25th Annual Report by the Diablo Canyon Independent Safety Committee, July 1, 2014—June 30, 2015
Preface | Executive Summary
Volume I TOC | Volume II TOC | PG&E Response | Contact the DCISC
25th Annual Report, Volume II, Exhibit B6, Minutes of the Diablo Canyon Independent Safety Committee on October 14–15, 2015 Public Meeting (Approved at the February 4, 2015 Public Meeting)
Tuesday & Wednesday, October 14–15, 2014, Point San Luis Conference, Room, Avila Lighthouse Suites, First & San Francisco Streets, Avila Beach, California
Notice of Meeting
A legal notice of the plant tour and public meeting and several display advertisements were published in local newspapers and mailed to the media and those persons on the Committee's service list. Information on the public tour and a copy of the meeting agenda were also posted on the Committee's website at www.dcisc.org.
I Call to Order–Roll Call
The October 14, 2014 public meeting of the Diablo Canyon Independent Safety Committee (DCISC), the seventy-second public meeting of the Committee, was called to order by Committee Chair Dr. Per Peterson at 1:30 P.M. at the Point San Luis Conference Facility at the Avila Lighthouse Suites in Avila Beach, California. Dr. Peterson welcomed the members of the public in attendance. Public meetings of the Committee may be viewed online in real-time over streaming video and are recorded for later broadcast on the local government access television channel (Channel 21). Dr. Peterson introduced and briefly reviewed the professional backgrounds and appointment of each of the members of the Committee.
- Committee Member Robert J. Budnitz
- Committee Member Peter Lam
- Committee Member Per F. Peterson
Dr. Peterson introduced and briefly reviewed the background of each of his fellow Members, Dr. Robert J. Budnitz and Dr. Peter Lam, as well as that of the Committee’s Technical Consultants Mr. R. Ferman Wardell and Mr. David C. Linnen and Assistant Legal Counsel Robert Rathie. Dr. Peterson recognized and introduced Ms. Maureen Zawalick, Pacific Gas & Electric Company (PG&E) Corporate Support Manager, who acts as the principal point of contact for the DCISC with PG&E and the Diablo Canyon Power Plant (DCPP).
III Public Comments and Communications
The Chair reviewed the procedures and advice from the agenda for the meeting concerning receipt of comments from members of the public wishing to address remarks to the Committee. The Chair advised time would be set aside for members of the public to comment on those matters listed on the agenda at the time the matter was considered by the Committee and inquired whether there were any members of the public present who wished to address remarks to the Committee on items not appearing on the agenda for the public meeting.
Ms. Sherry Lewis was recognized. Ms. Lewis stated she was speaking as a representative of the group San Luis Obispo Mothers for Peace (MFP) and inquired concerning a reference in the draft Minutes of the June 2014 public meeting of the Committee concerning a comment by Consultant Wardell on the effectiveness of DCPP’s program for addressing the Institute of Nuclear Power Operations (INPO) performance plan and what Ms. Lewis reported as a recent downgrading of DCPP by INPO in a recent evaluation. Mr. Rathie confirmed the version of the Minutes provided to Ms. Lewis was the same as included in the agenda packet for this meeting and the meeting minutes are simply a record of the discourse taking place during a public meeting. Dr. Budnitz commented that INPO is a nuclear industry organization which evaluates U.S. nuclear sites and its evaluations are not made public. The DCISC is afforded access to INPO reports concerning DCPP on a confidential basis and the Committee cannot comment on the substance of those evaluations in a public forum. Mr. Wardell confirmed Dr. Budnitz observation and stated the Nuclear Regulatory Commission (NRC) is also under certain constraints imposed by confidentiality restrictions in its use of information received from INPO.
Dr. Lam recognized the presence in the audience of Mr. Kevin Barker, Chief of Staff to California Energy Commission (CEC) Chairman Dr. Robert B. Weisenmiller, and Ms. Danielle Osborn Mills, CEC Senior Nuclear Policy Advisor. Ms. Osborn Mills addressed the Committee and stated she and Mr. Barker were happy to have the opportunity to attend this public meeting of the DCISC and she thanked the Committee Members for their service in providing a valuable benefit to members of the public and to PG&E as the operator of DCPP.
IV Consent Agenda
The only items on the Consent Agenda were approval of the Minutes of the Committee’s June 11–12, 2014, public meeting held in Avila Beach, and the Minutes of the Committee’s August 8, 2014, public meeting held in San Luis Obispo. Dr. Lam commented that these Minutes reflect a most robust and enthusiastic participation by members of the public at the June 2014 public meeting.
Items were discussed and reviewed for follow up or action and clarification was provided to the Committee’s Assistant Legal Counsel concerning certain references in the draft Minutes provided in the agenda packet for this meeting, and regarding necessary typographical and editorial corrections as well as concerning substantive changes to be made to the final version of the June and August 2014 Minutes which will be made in the final versions of both sets of Minutes which, for the June 2014 Minutes will become a part of the Committee’s 24th Annual Report on the Safety of Diablo Canyon Power Plant Operations (Annual Report) for the period July 1, 2013 to June 30, 2014, and for the August 2014 Minutes the 25th Annual Report for the period July 1, 2014 to June 30, 2015.
On a motion by Dr. Budnitz, seconded by Dr. Lam, the Minutes of the Committee’s June 2014 public meeting were approved as amended, subject to inclusion of the revisions discussed and changes provided to its Assistant Legal Counsel. On a motion by Dr. Budnitz, seconded by Dr. Lam, the Minutes of the Committee’s August 2014 public meeting were approved as amended, subject to inclusion of the revisions discussed and changes provided to its Assistant Legal Counsel.
Ms. Sherry Lewis, representing MFP, was recognized. In response to Ms. Lewis question Dr. Budnitz stated that each department at DCPP is made up of many sections. Ms. Lewis also suggested and the Members agreed that the Minutes be corrected to use the correct spelling of the Japanese word “Daini”.
Mr. Bill Dineen was recognized. Mr. Dineen thanked the DCISC for providing hearing assistance devices to attendees at its public meetings and he stated that DCPP would not be needed if more people had photovoltaic devices on their roofs as he does and which produces more electricity than he uses.
Ms. Rochelle Becker, the Executive Director of the Alliance for Nuclear Responsibility (A4NR) was recognized. Ms. Becker referred to comments she made at the June 2014 DCISC public meeting which were included in the Minutes of that meeting and clarified a statement that the position of the A4NR is that DCPP could continue to operate to the end of its current license only if it can do so safely and cost-effectively.
V Action Items
A. DCISC’s 24th Annual Report on Safety of Diablo Canyon Operations; July 1, 2013—June 30, 2014.
The Chairman reviewed the duty and obligation of the Committee to develop and make available its Annual Report on the safety of DCPP operations. Dr. Peterson stated preparation of the Annual Report was an intensive, collaborative effort led by Committee Technical Consultant Mr. R. Ferman Wardell. Dr. Lam remarked Mr. Wardell has done an outstanding job and deserves recognition and the thanks of the members of the Committee for his efforts. At Dr. Peterson’s request, Mr. Wardell reviewed the process employed by the Committee to develop its Annual Report for 2013–2014 and the single Recommendation from the Committee’s 24th Annual Report. Dr. Budnitz observed the Annual Report represents a compendium of the DCISC’s efforts over that twelve month period and its positions, policies, findings, conclusions and recommendation are set forth in the fact finding reports on which presentations are made at each public meeting during the Annual Report period.
Dr. Lam requested Consultant Linnen to briefly review the basis for the single recommendation, R14-1, in the 24th Annual Report. Mr. Linnen stated Recommendation R14-1 resulted from an event at DCPP during February 2013, when a maintenance activity to replace a fuse led to the de energizing of a 4 kV bus at a time when the affected unit was shut down and had no fuel within its reactor vessel. A Licensee Event Report (LER) was submitted by PG&E to the NRC and an extensive Root Cause Evaluation (RCE) was performed. The RCE identified two root causes one of which concerned the Maintenance organization leadership not being proactive in addressing human performance standards. Mr. Linnen stated the DCISC agreed with this aspect as a root cause. Nevertheless, the DCISC noted that there were a number of instances where the Maintenance and Operations organizations interacted prior to the event. Therefore, the DCISC based its Recommendation R14-1 upon its conclusion that Operations played a role commensurate with Maintenance in this event and recommended that DCPP reexamine the role of Operations in the event.
Mr. Rathie observed that, in accordance with the Restated Charter from the California Public Utilities Commission (CPUC), upon its approval, the Annual Report is provided to PG&E for its response which becomes a part of the final Annual Report. The Annual Report is then provided to the CPUC and to each of the Committee members’ appointing entities, the Governor, the California Attorney General and the Chair of the California Energy Commission as well as to the California Polytechnic University (Cal Poly) R.E. Kennedy Library and to public libraries in the local area, and on the Committee’s website at www.dcisc.org. On a motion by Dr. Budnitz, seconded by Dr. Lam, the Committee unanimously approved its Twenty-Fourth Annual Report PG&E’s on the Safety of Diablo Canyon Operations for the period July 1, 2013—June 30, 2014.
B. Update on Financial Matters and Committee Activities.
Mr. Rathie reported that a statement of revenue, assets, and liabilities was previously provided to the Members. He stated three payments under the grant which funds the DCISC activities have been received and, while it is difficult to budget as the Committee expends funds at different rates during a calendar year based upon its activities, it appears the DCISC will complete calendar year 2014 within the amount of the 2014 Grant. Any funds remaining unspent from 2014 will be returned to PG&E for credit to its ratepayers who provide all funds for DCISC operations. During calendar year 2013 the DCISC returned $73,750 .00 to PG&E’s ratepayers. Mr. Rathie directed the members’ attention to the pages in the agenda packet which included information on the dates for public meetings and fact-findings during the remainder of 2014 and for 2015 and he reported the dates for the June 2015 public meeting have been changed to June 16–17, 2015.
C. Discussion of Issues on Open Items List.
Dr. Peterson requested Consultant Wardell lead a review of items on the Open Items List, used by the Committee to track and follow issues, concerns, and information identified for subsequent action during fact-finding or public meetings. Dr. Budnitz observed there were 25 items on which the DCISC indicated it would take some action during the final quarter of 2014 and some of these items must necessarily be deferred. Items concerning which action was taken included the following:
|CO-12||Assess Flexible Power Operations||Defer to 1Q15 or later if new development occurs|
|CM-13||Maintenance Dept.||Rev Troubleshooting 1Q15 Defer balance to 2016|
|ET-5||Use of Social Media by ERO||Rev. Natl. Academy and NEI Reports prior to FF|
|RA-5||PRA Program||Move to 1Q15|
|RA-6||Monitor Seismic Fragility Analysis||Move to 1Q15|
|RP-13||PHC Rev. of Rad. Monitoring System||Schedule for Nov.2014 FF|
|SE-26||RPV Compliance Status||Schedule for 1Q15|
|SE-38||CFCU Modifications||Schedule for Nov.2014 FF|
|SF-1||Monitor ISFSI Operations||Coordinate with next transfer|
|SF-2||Relative Risk: Cask vs. Pool Storage||Add: (1) rev. potential for clad embrittlement due to hydriding;|
|(2) salt deposition by saltwater cooling towers & degradation of fuel storage canisters [Also follow—Closed Cooling item]|
|SC-3||Long Term Seismic Program||Schedule for 1Q15|
|SC-4||Monitor Tsunami Risk Analysis||Schedule for 1Q15 Rev. tsunami design basis & PRA|
|SC-8||Sewell Report||Open new item|
|LD-6||Observe operator license requal. class||Schedule for 2Q15FF|
|CL-3||Review Bechtel Closed Cooling Study||Coordinate/update with CL-5|
|CL-5||Once-Through Cooling||Continue to follow|
|BDB-6||FLEX Status||Delete comment on use of video|
|6/14 PM15||Post Annual Recommendations to Website||Update website|
During review of the Open Items List Dr. Budnitz provided an update on the tsunami report prepared in 2003 by Dr. Robert Sewell which was provided to the NRC and is the subject of a request made under the Freedom of Information Act by the DCISC to the NRC which is now under consideration. Dr. Budnitz reported the report by Dr. Sewell was called to the Committee’s attention by Mr. David Weisman, the Outreach Coordinator for A4NR.
VI Committee Member Reports and Discussion
A. Public Outreach, Site Visits and Other Committee Activities:
The Committee members and consultants reviewed and scheduled fact-finding visits and public meetings of the Committee as follows:
- Public meetings of the Committee were scheduled and confirmed for: February 4–5, June 16–17, October 21–22, 2015 and February 3–4, 2016.
- Fact-finding visits were confirmed and scheduled as follows:
-  November 19–20 RJB/RFW; December 2–3 PFP/DCL
-  January 21—22 PL/RFW; March 31—April 1 RJB/DCL; April 21–22 PL/RFW; May 19–20 PFP/DCL; July 7–8 RJB/RFW; August 5–6 PFP/DCL; September 29–30 PL/RFW; November 17–18 RJB/DCL; and December 9–10 PFP/RFW.
A short break followed
B. Documents Provided to the Committee:
Mr. Rathie directed the Committee's attention to the list of documents received since its last public meeting in June 2014. A copy of the list was included with the public agenda packet for this meeting.
VII Staff-Consultant Reports & Receive, Approve and Authorize Transmittal of Fact Finding Reports to PG&E
The Chair requested Consultant Wardell to report on a fact-finding visit to DCPP. Mr. Wardell reported on the August 13–14, fact-finding visit to DCPP with Dr. Peterson. Mr. Wardell reviewed the items and topics reviewed with PG&E during that visit.
- MIDAS (Meteorological Information and Dose Assessment System) Mr. Wardell reported MIDAS is used at DCPP in the event of a potential radioactive release to predict the path and magnitude of any radioactive plume and is used in conjunction with EPR2NET, which is used by control room personnel, and with the Emergency Assessment Response System (EARS) which determines if a radioactive release has taken place at the plant. MIDAS and EARS are used to help DCPP provide protective action recommendations to San Luis Obispo County (County) officials who analyze the data and decide on what actions to take. Once a full response team is in place at the County Sheriff’s office the County radio technicians and DCPP technicians in the Uniform Dose Assessment Center (UDAC) jointly take over responsibility for MIDAS and EARS. DCPP is now using the second MIDAS revision in conjunction with its seven meteorological tower and other weather instruments. Mr. Wardell stated MIDAS is an accurate system and its third revision is now available which will permit assessment of multi-point releases. The DCISC team reviewed the use of EPR2NET and the new MIDAS simulation. He stated DCPP is now in the process of implementing the third revision to MIDAS which should be in place by the end of 2014. He suggested the DCISC follow up on the implementation effort during first part of 2015.
- Safety-Security Interface Mr. Wardell stated DCPP has a formal process to assess security-related changes for their potential impact on the plant’s safety features. These reviews are conducted by the Engineering, Maintenance and Operations Departments and are coordinated with the Security Department. The DCISC fact-finding team found the program to be satisfactorily implemented.
- Spent Fuel Pool Instrumentation—Mr. Wardell reported the two DCPP Spent Fuel Pools (SFP) presently use level instrumentation which is mounted on the side of each pool. Since the accident at the Fukushima Daiichi Plant in Japan (Fukushima), the NRC has required nuclear power plants to install SFP primary and backup remote access level instrumentation supported by independent electrical power to primary and secondary instrumentation. DCPP is installing two instruments provided by Westinghouse Electric Company in each SFP which will be powered by different electrical bus bars (buses) with backup power provided for 72-hours with a local display within the Fuel Handling Building with the data also being fed to the Control Rooms. Mr. Wardell stated the team inquired, in response to a comment from a member of the public at an earlier public meeting, why a video monitor could not be used and the DCISC team was informed that steam and other limitations make the use of video monitoring impractical for level monitoring purposes. He stated the new instruments will be installed by May of 2015 for DCPP Unit-1 (U-1) and by the end of June 2015 for DCPP Unit-2 (U-2).
- Emergency Auxiliary Saltwater System (ASW) Layout Test Mr. Wardell described the function of the ASW as to provide access to the last cooling source, also termed the ultimate heat sink, to cool plant safety-related systems. During the accident at Fukushima a loss of ASW capabilities was experienced and DCPP is creating an Emergency ASW as part of its emergency response strategies and systems, an effort termed“FLEX” which has been developed by the nuclear industry in the aftermath of Fukushima. Mr. Wardell displayed the path of the piping used by the Emergency ASW to tie-in to the existing underground auxiliary service water and water piping and the location of the pumps used to provide suction for the Emergency ASW and he reported the components for the Emergency ASW are stored on trailers and within storage containers. Mr. Wardell reported the Emergency ASW uses diesel-driven pumps and no electricity is required. He reported that while DCPP has laid out the piping runs using quick joint connections and placed the pump in their locations, because the plant does not yet have the necessary permit water could not be pumped through the flexible piping, which ends in a kelp cage which extends into the ocean. He displayed several photos of the fact-finding team on site inspecting the system components. Dr. Peterson commented that the environmental permitting requirements which pose an impediment to actually testing the system in the ocean seem unnecessarily burdensome in context of nuclear safety, particularly as DCPP pumps millions of gallons of ocean water through its cooling systems on a daily basis. He stated the DCISC should follow up on the Emergency ASW permitting issue. In response to Dr. Budnitz’ inquiry, Mr. Wardell stated DCPP estimates it would take approximately 128 hours to deploy the Emergency ASW and Dr. Peterson observed that as the Emergency ASW function is to provide water for long term cooling, but in the short term after an accident cooling can be provided by injecting water into the steam generators (SG) and the SFP, this period appears to be adequate. Dr. Peterson stated it is important that training be sufficiently realistic that it generate confidence that under actual accident conditions that would disable the ASW that DCPP would be capable of responding. Mr. Wardell observed when the Emergency ASW was tested in May 2014 two pumps experienced problems and he recommended the DCISC follow up on future tests of the Emergency ASW pumps.
- Design Quality Effectiveness Mr. Wardell reported during the seventeenth refueling outage for U-1 (1R17) some field modifications experienced problems with design and corrective actions were taken during 1R18 which proved to be effective, although problems were also experienced during 1R18. DCPP reviewed 64 major and minor projects and determined 92% were accomplished without experiencing design quality problems and the plant is reviewing further corrective actions to improve its design process and Mr. Wardell stated the DCISC should continue to review issues of design quality released to the field which are now measured monthly by DCPP. Design quality is presently rated as “White” which is considered to be satisfactory by the plant.
- DCPP Review of Reactor Trip Commonalities—The DCISC fact-finding team reviewed the three reactor trips which have occurred due to flashover events in the switchyard. Mr. Wardell reported a thorough root cause evaluation (RCE) was performed and corrective actions were identified. An outside consultant was engaged to review the issue for commonalities and these were found to include contaminant buildup on insulators, bushings, and lightning arresters on high voltage equipment due, in part, to salt spray and dampness, dust, and particulate deposits due to exhaust products and soot from operation of the emergency diesel generators (EDG). The plant no longer performs washing activities on the insulators or transformers while the plant is at full power but reduces power and isolates transformers during washing. Bushings in certain insulators are also being changed and replaced with bushings that can better withstand contaminants. One transformer has also been moved to a more protected area.
- Seismic Fragility PRA—the probabilistic risk assessment (PRA) of seismic fragility was undertaken to determine the capability of safety-related systems, structures and components (SSC) in the plant to withstand seismic activity. Dr. Peterson stated that the absolute magnitude of an earthquake is not the most important factor in seismic fragility, rather it is the duration and acceleration at specific frequencies which is the principal factor in determining the vulnerability and sensitivity of SSCs, such as electrical equipment and nuclear fuel. There are also questions whether replacement or repair will be possible using FLEX strategies and whether personnel will survive an earthquake and retain the ability to retain access to necessary areas of the plant. Dr. Peterson observed when a situation departs from a plant’s design basis, human error and equipment damage can potentially exceed what was anticipated and training must be provided and guidelines need to remain available and this is an important area for the DCISC to follow. Dr. Peterson observed a lack of preparation, poor or no access to instrumentation, and poor decision making processes contributed significantly to difficulties experienced during the accident at Fukushima. In response to Dr. Budnitz’ inquiry, Mr. Wardell confirmed that in examining and evaluating SSCs at DCPP for unanticipated issues concerning seismic fragility there has been nothing discovered to date which would call into questions the SSC safety during an earthquake. Dr. Budnitz observed the PRA is being undertaken at the request of the NRC and is expected to be completed by mid to late 2015. The NRC is also requiring all nuclear power plants to review and evaluate the seismic capacity of their FLEX equipment and to report the results by the end of December 2014. Dr. Budnitz reported that he presently serves as an advisor to the NRC staff on that program to assist in the review of the FLEX equipment capabilities but he will recuse himself from the review of the submission by DCPP. Dr. Peterson stated an important issue for the Committee to follow concerns the questions of what are the likely states of damage in a plant that could follow a BDB earthquake event and whether the impact of that damage on access and personnel is going to be adequately addressed in context of the FLEX review.
- NFPA-805 Update Mr. Wardell reported nuclear power plant fire regulations now fall under Title 10 Code of Federal Regulations (CFR) Part 50 Appendix R which he described as employing a deterministic approach to fire safety. The National Fire Protection Association (NFPA) has now developed Standard 805 Regulation, a standard which retains some deterministic aspects but also adds risk-informed performance standards which provide what Mr. Wardell described as a more realistic look at fire protection. Using the 10 CFR App. R regulatory scheme DCPP has identified 105 separate and distinct fire areas. DCPP made the decision to transition to NFPA-805 regulations and the eight modifications required for this transition for each unit should be complete by their twentieth refueling outages.
- Reactivity Management Mr. Wardell reported the DCISC team reviewed this topic, which measures the fractional change in neutron population from one neutron generation cycle to the next as a measure of reactivity and he described this as a direct measure of nuclear safety. He reported the DCISC team found the DCPP procedures to be satisfactory including the role and function of the Reactivity Management Leadership Team which reviews monthly those events which impact reactivity. U-1 is currently in “White”, or satisfactory status, while U-2 is in “Yellow” status which indicates improvement is needed. Mr. Wardell reported the “Yellow” status for U-2 was due to the three flashover events which resulted in reactor trips and because a 12-month rolling average is used to measure reactivity events, both units should be in “Green” status by the end of October 2014.
- 2R18 Outage Plan—the fact-finding team reviewed the Outage Safety Plan which is developed to allow the outage to proceed safely as plant systems and components are taken out of service or tested and to ensure defense in depth is maintained at all times so as to prevent accidents and to mitigate any that occur. The DCISC representatives found the Outage Safety Plan for 2R18 to be satisfactory.
- Meet with NRC Resident Inspectors—the DCISC representatives met with both NRC Resident Inspectors to discuss the Bechtel Assessment concerning the proposal for the elimination of once-through cooling at DCPP, the seismic hazard studies, and the review of FLEX equipment. The DCISC representatives also discussed the Committee’s efforts to obtain a copy of the 2003 Tsunami Study prepared by Dr. Robert Sewell
- Chemistry Program—Mr. Wardell reported the DCISC fact-finding team reviewed the Chemistry Program which is used to manage water chemistry in primary and secondary plant systems, to minimize corrosion and biofouling, and to manage reactivity through the use of boron the Reactor Coolant System (RCS). The Chemistry effectiveness index measures various parameters of the Chemistry Program and Mr. Wardell reported U-1 is currently in “Green” status while U-2, due to iron in the SG secondary side caused by starting up the unit, is presently in“Yellow”status.
- DCISC Member Meeting with DCPP Site Vice President - Dr. Peterson reviewed the items reviewed during the fact-finding meeting.
Mr. Bill Dineen, a member of the audience, was recognized. Mr. Dineen remarked that installation of rooftop solar photovoltaic units could make DCPP unnecessary in the future.
Ms. Rochelle Becker of A4NR was recognized. She stated the issue of the reactor trips at DCPP was presently under review by the CPUC in its Energy Resource Recovery Account (ERRA) proceedings and she reported that the Office of Ratepayer Advocates has posed some excellent questions which the DCISC should review. Dr. Peterson stated the Committee would review the ERRA briefs cited by Ms. Becker.
Ms. Sherry Lewis of MFP was recognized. Ms. Lewis inquired whether the flexible piping used with the Emergency ASW might be used for the entirety of the Emergency ASW piping if necessary to run piping around obstructions. She further inquired whether PRA analysis leaves out loss of coolant accidents from consideration and she observed that there may be a number of considerations which are not part of any PRA analysis which should be considered. Finally she inquired whether the reactivity management discussed by Mr. Wardell occurs inside Containment. Mr. Wardell replied that there is sufficient piping available, both solid and flexible, to cope with obstructions and flexible piping is required for the piping run which extends into the ocean and, if necessary, flexible piping could be inserted between solid piping runs. Mr. Wardell confirmed that the reactivity management he discussed during his presentation occurs entirely within Containment. Dr. Budnitz confirmed that PRA analyses include loss of coolant accident scenarios of all different magnitudes as such events are possible initiating events for an accident.
Upon a motion by Dr. Budnitz, seconded by Dr. Lam, the August 13–14, 2014 Fact Finding Report was approved and its transmittal to PG&E authorized.
Once the Committee’s fact finding reports are approved at a public meeting they are no longer considered to be in draft form and are made available in a binder for inspection by members of the public, together with information concerning the professional backgrounds of the Committee’s technical consultants involved with preparation of its fact finding reports. Fact finding reports become part of DCISC’s Annual Reports.
The Chair requested Consultant Linnen to report on the next fact-finding visit to DCPP. Mr. Linnen reported on the June 24–25, 2014, fact-finding visit to DCPP with Dr. Budnitz. Topics reviewed with PG&E during that visit included the following.
- Trend in NRC Violations on Work Practices and Human Error—Mr. Linnen reported this review was a status check on an issue that had previously been reviewed in January 2014 and stemmed from three station level human performance events that occurred during the 4th quarter of 2013. The fact-finding team noted during a review this past June that the station had taken action on this issue which included more observations of work activities by supervisors and managers and examining lower level events more deeply for causal factors of human performance problems. Each work activity was being assigned a level of risk to maintain a consciousness of the potential impact of the work activity. The DCISC representatives noted from review of station performance reports that improvement was being made. The station’s most recent Plant Performance Improvement Report indicates that DCPP has not experienced a significant station level human performance event since February of 2014. Also, lower level events are being reported and tracked, and are referred to as Department Level events. During January through March 2014 the station experienced 16 of these lower level human performance problems, and during April through June there were 3. Mr. Linnen remarked the Committee should review this topic again during the 1st quarter of 2015 to see whether this improvement is being sustained.
- Nuclear Fuel Performance—the fact-finding team reviewed this as a periodic review regarding the station’s status with regard to maintaining the integrity of the nuclear fuel and preventing radioactive fission products from leaking from the fuel into the reactor coolant. In this regard Mr. Linnen observed the industry has been implementing a program aimed at achieving zero fuel leaks that was developed by the Electric Power Research Institute. The DCISC representatives noted in the review that DCPP has experienced no fuel leaks since 2011.
- Management of Online Maintenance Risk—Mr. Linnen reported this activity is undertaken by the plant to ensure that conducting maintenance on equipment during plant operation doesn’t pose an unacceptable risk to nuclear safety. To this end, nuclear organizations screen desired work activities for their potential risk to the plant. This program has become increasingly refined over the years so that the workers themselves are becoming more knowledgeable of the potential impact they might have on plant operation through their work. He stated station performance in this area was rated as “Green”, or healthy, for every month in 2014.
- Outage Planning and Execution Action Plan—Mr. Linnen reported the fact-finding team examined DCPP’s performance during 1R18 compared to its goals for the outage, as well as to previous outage performance. Key aspects were that the station experienced no station level human performance events and only 4 department level human performance events in 1R18 compared to 13 department level events in the prior refueling outage. Spent fuel cooling was interrupted for several minutes during 1R18 due to a disturbance in the electrical grid and the pump was then manually started by Operations. Department level human performance during 1R18 was the best in the station’s history. With regard to industrial safety, there were no lost time injuries and no recordable injuries during the outage. There were 13 events of personnel receiving radioactive contamination compared to the goal of 16, and the outage was completed in 32 days compared to a goal of 33. Mr. Linnen reported a significant number of major work activities were conducted as planned during refueling outage 1R18, including replacement of a vital battery, polar crane modifications, containment fan cooler unit (CFCU) damper modifications, and overhauls of the motors of a circulating water pump and a Reactor Coolant Pump. One problem that arose during return to power was due to the misalignment of the pump shaft and motor shaft of Reactor Coolant Pump 1–3 by the vendor which resulted in abnormal vibration and the need to take Unit 1 offline for 10 days shortly after startup in order to realign the pump and motor shafts.
- Management of Single Point Vulnerability—Mr. Linnen stated this topic pertains to any component whose failure by itself could result in a reactor trip, a turbine trip, or a decrease in power of greater than two percent. He observed that this may appear to be primarily an operability issue because if such a component fails, the unit shuts down or reduces power. However, a clear objective from a safety standpoint is to avoid any unanticipated transients. Dr. Budnitz remarked on the need to examine and understand why things go wrong in order to learn more generally about maintenance and follow up procedures. Mr. Linnen agreed and stated the issue of identifying single point vulnerabilities generated industry-wide efforts in the time period 2002-2006 and involves organizations such as the Electric Power Research Institute (EPRI) and the Nuclear Energy Institute (NEI). Mr. Linnen stated one example of a single point vulnerability occurred in 2013 and stemmed from the review of the auxiliary and startup transformers, where the transformer oil was evaluated to ensure that it was in fact meeting industry standards. A similar situation involved the single phase generator transformers when one transformer was found to have high moisture and oxygen in the oil which resulted in the replacement of that transformer.
- Critical Equipment Clock Resets—Mr. Linnen discussed the team’s review of Critical Equipment Event Clock Resets which are reflected in:
- Reactor trips, either automatic or manual.
- Events requiring the submission of a Licensee Event Report to the NRC.
- A Limiting Condition of Operation (which is a situation that would require the plant to shut down or derate within 24 hours).
- Unplanned reduction in power of more than two percent.
He remarked that since these types of events occur infrequently performance is assessed based upon the numbers that occur on a rolling 12-month basis. That is, every month, the number of events in the prior 12 months is tabulated. At the time of the DCISC review, looking back at that time on each month of the prior 12 months, it was noted that the plant had been experiencing between 9 and 11 resets during each of the rolling 12-month periods. However, Mr. Linnen reported most of those events occurred in the early months of the most recent 12-month period, and considerable improvement was noted when moving forward through that period. During the prior nine month period at the time of the DCISC review there were only four resets (which would translate to between 5 and 6 in a 12 month period) and during the most recent six month period there were two resets (i.e. annualized 4 events per 12 month period). Mr. Linnen stated the fact-finding team believes DCPP recognizes that equipment aging can be a factor in the types of events that result in clock resets, and the station is increasing its efforts to monitor and document aging and degradation mechanisms.
- Auxiliary Feedwater System Health—Mr. Linnen reported the Auxiliary Feedwater System (AFW) is a safety-related system that is relied upon to prevent damage to the nuclear fuel and to prevent over pressurization of the RCS in the event of transients such as a loss of normal main feedwater or a pipe rupture on the secondary side. The station’s color coding system for plant system health rated U-1’s AFW System as “White” and U-2’s as “Green”. He remarked the reason for U-1’s “White” rating pertains to the new auto/manual hand stations at the Hot Shutdown Panel as the demand button needs to be jogged in order for the controller to respond if demand is in the range of 0-10% or 90-100%. U-2 does not have this problem. The DCISC fact-finding team concluded that the few existing system health issues do not appear to be significant enough to negatively affect system reliability or plant safety. Nevertheless, considering the significance of this safety system, the fact-finding team felt that DCISC should conduct its next review of the AFW system prior to the end of 2015.
- 2013 Annual Radioactive Effluent Release Report and Annual Radiological Environmental Operating Report—Mr. Linnen summarized this topic and reported for 2013, the station’s releases of radioactive gases and liquids would each provide a calculated whole body radiation dose to a person who resided continually at the site boundary throughout the year that amounts to less than two one-hundredths of one percent of the Technical Specification (TS) limits, and ambient radiation levels did not change, and were within the pre operational range throughout 2013.
- Plans to Address 230 kV System Issues—Mr. Linnen reported this system is DCPP’s primary source of power to its vital electrical busses in the event of a loss of a station turbine generator. The station’s Emergency Diesel Generators (EDGs) are the backups to the 230 kV System. He reported an emerging issue is that as the electric demand in the region increases this could cause voltage variations on the 230 kV system, which could affect the system’s reliability if called upon to supply the plant with vital electric power. To address this DCPP has been engaged in a number of activities. One is to install high voltage stabilizing devices in the 230 kV switchyard. Another is to transfer non-essential 4 kV loads away from the 4 kV vital busses. The station is also pursuing a license amendment which seeks NRC approval to replace the current undervoltage relays with more robust relays, and plans are also in the works to install Voltage/Amperage/Resistance (or VAR) Compensators for stabilizing voltage in the 230 kV switchyard. Mr. Linnen remarked the DCISC representatives concluded that the station’s approach to this issue and the options being examining appear reasonable, and the Committee should continue to follow this issue.
- Component Mispositionings—Mr. Linnen reported that over the years, the station has done a very good job of avoiding significant component mispositionings that would have had a severe or major impact on the facility. Lower level events appear to be under better control having decreased in number steadily. These improvements have been attributed to training and greater emphasis during shift briefings and pre-job briefings.
- Operations Training and Time Critical Operator Action— Mr. Linnen reported that the training that was observed on this topic was exemplary. The instructor was highly knowledgeable with the subject and with the training material.
- Engineering Training—The DCISC fact-finding team also observed this training session which was conducted by an instructor who was presenting this material for the first time. The session was primarily a lecture which the DCISC team understood took longer than was expected and did not stimulate the degree of involvement of the engineers as the team found with the Operations training.
- Meeting with NRC Resident Inspector—Dr. Budnitz reported he met with both the NRC resident inspectors and discussed the DCISC’s efforts to obtain the release of the tsunami report prepared in 2003 by Dr. Robert Sewell.
- DCISC Member Dr. Budnitz Discussion with PG&E Chief Nuclear Officer.
The Chair requested Consultant Linnen continue his report with a report on the next fact-finding visit to DCPP. Mr. Linnen reported on the September 17–18, 2014, fact-finding visit to DCPP with Dr. Lam. Topics reviewed with PG&E during that visit were reviewed as follows:
- Maintenance Department Performance—Mr. Linnen stated during this most recent visit the DCISC representatives learned that managers and directors have continued observations of workers on a periodic basis and reported the results to the Plant Manager or Operations Manager. The results of these observations have led to a reduction in the number of outage maintenance rework activities from 92 in 2012, to 26 in 2013, and to 19 in 1R18.
- Results of Recent Audits by Quality Verification (QV)—Mr. Linnen reported this topic is routinely reviewed by the Committee to gain insights on the station’s performance from QV’s perspective. Mr. Linnen remarked that QV is extraordinarily familiar with the NRC requirements and QV audits are often validated by NRC audits. The Quality Assurance (QA) auditing group consists of full-time QV personnel. The QV’s assessment group looks more broadly, without focusing necessarily on NRC requirements, and consists of station line personnel who are loaned temporarily to QV and who evaluate performance with respect to management standards that strive to go beyond the federal requirements. This additional approach provides a benefit to the station by providing the line organization with a better understanding of desired standards of performance. The DCISC team suggests that the Committee follow up on an audit finding that the station’s performance with respect to entries into Limiting Conditions of Operation had been “Red”, or unsatisfactory for most months since June 2013.
Mr. Linnen remarked that the remaining topics that he would discuss were selected because they had not been reviewed by the DCISC for a number of years, rather than because of any noted performance deficiency.
- Self-Assessment Program—The Self-assessment Program itself was last reviewed in November 2011, and Mr. Linnen reported its structure appears to have remained essentially intact since that time. The results of these assessments are included in the station’s monthly Plant Performance Improvement Report and the DCISC fact-finding team concluded that the program appears to be in continuing good health and the program reports well designed and well structured. It was determined that the DCISC need not conduct another status check on this program as a whole for at least another two to three years, unless dictated by future performance issues.
- System Engineering Function—Mr. Linnen stated this is a very broad topic, and the team’s review consisted of an overview of this function as a whole rather than as an examination of a particular system. It was last reviewed in this aggregate manner back in 2011. The fact-finding team concluded that the System Engineering Function continues to be a very useful mechanism for documenting and discussing system issues, identifying priorities, tracking progress, and helping to gauge overall plant performance.
- DC Power System Health—Mr. Linnen reported this is a battery powered system that is kept charged with dedicated battery chargers. The information recently obtained by the DCISC showed that the systems in both units were rated “Green”. In addition, all of the individual performance categories for both units, such as Reliability, Material Condition, and Operations Concerns, were rated “Green” as well. There was one performance sub-category in both units that was not rated “Green”. That sub-category was Aging Issues Affecting Reliability. This pertains not to battery cells, but rather to circuit breakers in the system that are undergoing replacement due to aging (grease hardening issue which can affect reliability). Station’s plans are to complete the replacements by the end of refueling outages 1R19 and 2R19 and Mr. Linnen reported the system remains completely functional.
- Reactor Coolant System Health—The DCISC last reviewed this system in May 2009. Since that time U-2 suffered a seal failure of Reactor Coolant Pump 2-2 which took U-2 offline during 2R17 and when U-1 was coming out of 1R18 there was excessive seal leakage from Reactor Coolant Pump 1–3 due to misalignment of pump and motor shafts. Mr. Linnen reported that the fact-finding team concluded that DCISC might consider conducting another fact-finding visit on this system during the next 12 months.
- Vibration Monitoring Program—Mr. Linnen observed this topic was last reviewed in 2011, and is part of the station’s Predictive Maintenance Program, which itself is part of Reliability Centered Maintenance. The plant has permanent vibration sensors with remote Control Room readouts on its Reactor Coolant Pumps, Turbine Generators, and Main Feedwater Pumps. There are also about 300 other components that are monitored with portable vibration detecting equipment, mostly on a monthly frequency. The DCISC representatives were provided a copy of the station’s Predictive Maintenance Watch List, which listed components with elevated vibration, components with elevated temperatures, and abnormal oil samples, and the timetables for acting on the few vibration issues appeared to be reasonable. Mr. Linnen reported the total list had several dozen entries, and about one third of them pertained to vibration.
- Compressed Air System Health—Mr. Linnen remarked the next topic covered during the fact-finding concerned the Compressed Air System which was last reviewed in 2011. The system serves both units and is divided into two subsystems: Instrument Air and Service Air. Three Plant Air Compressors (PACs 5, 6, & 7) serve as the source of air for Instrument Air. These compressors are rotated one at a time, each for a week, to serve the plant. Because the Compressed Air System is not fully safety-related the valves required for safe shutdown are supplied with an additional source of air from the Backup Air/Nitrogen System. This is a passive pressure system of a Class 1 design with air or nitrogen accumulators located with and dedicated to each safe-shutdown valve. These are seismically designed to resist earthquakes and require no electrical power. Each is designed with capacity adequate for valve operation to assure safe shutdown. Four additional full-capacity compressors (PACs 0-1 through 0-4) are maintained on site and are intended to serve the system at any time when called upon, and are also to serve in a secondary role during refueling outages. However, as the fact-finding team understands, the compressors have not operated during the past 15 to 20 years. During outages, two additional diesel driven air compressors are brought onsite and are the primary source of compressed air during the outages. The System Health Report rates the system as “Yellow” or deficient. According to the grading system a grade of “White” could have been justified but the rating was purposefully downgraded to call attention to recent reliability problems of the three primary compressors. Mr. Linnen reported PAC 0-5 failed due to various components reaching the end of their useful lives and producing abnormal noise while operating. For part of the time when PAC-05 was unavailable, PAC-07 was also unavailable due to an oil leak from a degraded hose. This caused both operating nuclear units to rely on only one compressor, PAC-06. In addition, the Health Report noted that PAC-07 and its instrument panel are located outside the Turbine Building. In particular, Mr. Linnen stated the instrument and control unit is facing in a direction that exposes the panel directly to the sun and also to rain and saltwater impingement. Consequently, the instrumentation, controls, indicating lights, and temperature trip switches are unnecessarily degrading due to the harsh environment and the controls require frequent replacement. On another occasion PAC-06 would not shut down automatically on compressor high discharge pressure, which would lift the system relief valves. The DCISC fact-finding team concluded that although the Compressed Air System has remained operational and is served by a Back-up Air Nitrogen System for the pneumatically operated safe-shutdown valves, it has experienced a number of challenges to operability, including equipment aging, deterioration, and failure. Also, installed equipment that could serve as backups to the three primary air compressors has apparently not operated for some time. The station has recognized and documented these issues and has plans to address them. Based on the information that was provided, the fact-finding team concluded the Committee should take time to reexamine this system more closely, including a system walkdown, in the near future.
- Margin Management Program—The DCISC last reviewed this system in 2011. Margin is a concept and a principle defined as conservatism, that is, a safety factor, design factor, buffer, or cushion included in the design and analysis of every plant structure, system or component (SSC) from a procedural, design, operations and maintenance standpoint in order to accommodate a variety of factors. Putting all of this into practice requires the involvement of SSC engineers, the Margin Management Subcommittee, and DCPP’s senior station managers comprising the Plant Health Committee. Overall Mr. Linnen stated the program and its infrastructure (procedures and processes) and implementation were rated as “green,” or healthy at the time of the review. However, the Equipment Cornerstone was rated as “Red,” or unhealthy, due to multiple open margin issues during the last 12 months. Examples included a corroded firewater header between the units, the debris loading margin for the Residual Heat Removal System, and the loading margin for EDGs for both units. Mr. Linnen stated the fact-finding team concluded the DCISC should focus on the Margin Management Program during a future review.
- Meeting with NRC Senior Resident Inspector.
- DCISC Member’s Discussion with DCPP Site Vice President.
Following Mr. Linnen’s presentation, Mr. David Weisman of the A4NR was recognized. Mr. Weisman asked for confirmation from the DCISC that a formal request under the Freedom of Information Act has been made by the DCISC of the NRC for release of or access to the tsunami report prepared in 2003 by Dr. Robert Sewell. Dr. Budnitz confirmed that such a request had been made and that a copy, along with a copy of an earlier letter to the NRC Resident Inspector for DCPP, was included in the correspondence with the agenda packet for this meeting. Mr. Weisman then inquired whether, if the report were released in a form restricted to review by the DCISC, whether the DCISC would be allowed to share the report with PG&E. Dr. Budnitz responded that the Committee would review the conditions under which review might be granted with its Legal Counsel’s office prior to accepting the report with restrictive conditions. Dr. Lam stated that he appreciated Mr. Weisman bringing the report to the attention of the DCISC as it was his belief that the matter advances the Committee’s safety agenda.
Upon a motion by Dr. Budnitz, seconded by Dr. Lam, the June 24-25 and September 17-18, 2014 Fact Finding Reports were approved and their transmittal to PG&E authorized.
The Chair requested Assistant Legal Counsel Rathie to report on administrative, regulatory and legal matters. Mr. Rathie reported that the office of legal counsel has been involved with a number of administrative matters stemming from the Committee’s public meeting on August 8, 2014, including responding to inquiries from members of the public and making the draft of the Evaluation of the Bechtel Addendum to the Final Assessment available on the DCISC website, in draft form and in a form which shows changes from the earlier draft of August 11, 2014, which was posted to the DCISC website after the public meeting on August 8, 2014. Mr. Rathie reported information has been received concerning a meeting of the CPUC’s Independent Peer Review Panel (IPRP) on October 23, 2014, in San Francisco, California. He reported that he accompanied Dr. Lam to a meeting with the CEC Chair, the Chair’s Chief of Staff, CEC Senior Nuclear Policy Advisor, and the CEC’s Executive Director on October 1, 2014, in Sacramento, California. He remarked that the Governor’s office announced the reappointment of Dr. Peterson on September 10, 2014, to a three-year term on the DCISC from 2014 to 2017. The CPUC is now advertising for candidates for the CEC appointment to the DCISC for the 2015-2018 term. Mr. Rathie concluded his remarks by reporting that visits to the DCISC website (www.dcisc.org) averaged 39 visitors during the Committee’s public meetings in the period of the 24th Annual Report (July 1, 2013—June 30, 2014) and during that period the website has averaged 620 unique visitors to the site every month with most visitors coming from (in order): the United States, Ukraine, Finland, France, the Russian Federation, and China.
Copies of correspondence sent and received at the office of the Committee's Legal Counsel since the last public meeting of the Committee in June 2014 were included with the public agenda packet for this meeting.
IX Adjourn Morning Meeting
The Chair adjourned the morning meeting of the DCISC at 12:05 P.M.
X Reconvene For Afternoon Meeting
Dr. Peterson convened the afternoon meeting of the DCISC at 1:30 P.M.
XI Committee Member Comments
There were no comments at this time from the Committee members.
XII Public Comments and Communications
Dr. Peterson invited any member of the public present to address comments to the Committee on topics not on the agenda.
Mr. Bill Dineen, a resident of Nipomo, California was recognized. Mr. Dineen stated he was previously a biology professor at a college and became concerned about what was to be done with nuclear waste in 1977. He was arrested during that year along with others at the entrance to the Diablo Canyon site. He again posed the question of what was to be done with nuclear waste which he described as terrible legacy for future generations. He stated he has inquired of PG&E on how long nuclear waste lasts but has not received a satisfactory answer.
Dr. Gene Nelson, a resident of San Luis Obispo, California, was recognized. Dr. Nelson stated he holds a degree in radiation biophysics and serves on the Physical Sciences Division at Cuesta College and recently served in the engineering faculty at Cal Poly. He stated he is concerned about what he sees as a profit motive by organizations which assert an interest in public safety and he commented that his inquiries have demonstrated fear mongering can be very profitable. He stated he takes particular exception to organizations taking funds provided by electric ratepayers such as the Alliance for Nuclear Responsibility and the San Luis Obispo Mothers for Peace. Dr. Nelson stated the CPUC provides information on compensation provided on its web page as intervener compensation which is paid by public utilities from funds collected from their ratepayers and he provided information on hourly rates and total compensation for certain individuals.
Mr. Joey Racano, the Director of the California Ocean Outfall Group, was recognized. Mr. Racano stated his group deals with ocean outfall issues and he was speaking on behalf of what he characterized as a priesthood charged with guarding nuclear waste from the present day to the year 1,002,014. He commented the southern sea otter is a species listed as endangered and PG&E in performing seismic testing implanted sea otters with listening devices which have not been removed. He reported a new program is being implemented to measure levels of Strontium 90 in baby’s teeth which he remarked can only come from nuclear activities.
Mr. Steve Cleaver, a physics educator, engineer and ocean surveyor and local resident was recognized. Mr. Cleaver stated his belief that there is no real need for the elimination of once-through cooling by DCPP as there is little or no measurable effect on the fisheries as opposed to the huge impact proposed for the terrestrial environment and it appears to him the solution is worse than the problem. Mr. Cleaver stated that the alternatives being proposed for replacing once-through cooling at DCPP would, in his opinion, have a huge impact on plant safety.
Mr. William Gloege, a resident of Orcutt, California was recognized. Mr. Gloege stated he was thankful for DCPP providing clean air and less soot, smoke and ozone than would be produced by electricity generated from fossil fuel. He commented his wish would be that all industries in the U.S. operated with safety records comparable to DCPP. Mr. Gloege stated the opponents of nuclear power he has met are nice people and he directed his comments to those persons asking that they take another look at alternatives to nuclear power because closing a nuclear plant results in many tons of carbon being added to the atmosphere and he remarked this has been the case with South California Edison Company’s closure of its San Onofre Nuclear Generating Stations (SONGS). He remarked carbon in the atmosphere is partly responsible for the current drought in California and for global warming effects. He stated there are links between leadership of antinuclear groups and the fossil fuel industry.
Ms. Katherine Perepsky, a resident of Nevada City, California and owner of a timeshare in San Luis Bay was recognized. Ms. Perepsky stated she was a realtor and the presence of DCPP in the local area requires property owners to sign an acknowledgment of the plant presence in the area. She remarked DCPP is situated on seismic faults and after Fukushima it is known that worst case scenarios may occur. Mr. Perepsky stated that she is aware of the emergency siren exercises but is unaware of any plans in place to address evacuation routing. She remarked that since she has been visiting the local area for ten years she has noted a lack of sea life in the area and wonders if that is associated with the presence of DCPP.
Ms. Sherry Lewis, a representative of MFP, was recognized. Ms. Lewis stated that radiation was the worst pollution in the world and much worse than that caused by fossil fuel. She stated that the medical aspects of radiation have not been properly tested and that if a radiological accident were to occur not only the present but future generations would be affected.
Ms. Elizabeth Brousse, a representative of MFP, was recognized. Ms. Brousse stated that the DCISC failed to follow the criteria the authors set forth in the Evaluation of the Addendum by the Bechtel Corporation to its Final Assessment concerning the elimination of once-through cooling at DCPP. She stated the Evaluation fails to assess dangers to public and environmental safety of the plant’s current use of its once-through cooling system or to address the environmental dangers associated with an earlier proposal by Bechtel which the DCISC has affirmed as safe. She stated information obtained from PG&E concerning levels of salt deposition on sample coupons demonstrated that U-2 main transformer area experiences higher levels of salt deposition than for U-1 which accounts for the major problems U-2 has experienced with flashover events, yet the Evaluation fails to acknowledge that this was caused by the antiquated once-through cooling system which is required by law to be retired. Ms. Brousse stated the Evaluation proves the once-through cooling system is the cause of problems but the Evaluation fails to state this. She inquired whether the flashover problems were a safety problem. She requested that the DCISC provide her with information on how often spray from the once-through cooling system caused flashover events in the last ten years and whether the DCISC sees this as a safety problem. If so, Ms. Brousse demanded that this observation be included in the Evaluation.
Mr. Joe Olveira, a resident of Orcutt, California was recognized, Mr. Olveira stated nuclear energy is the safest form of electric energy in the world according to scientific fact.
Ms. Linda Seeley, a representative of MFP, was recognized. Ms. Seeley inquired whether Ms. Brousse’s comments should have been made at the time the DCISC considered the Evaluation. Dr. Peterson stated that would have been in accordance with Committee protocol but that Ms. Brousse’s comments would be considered by the Members nevertheless.
Dr. Peterson thanked the members of the public for their comments and stated the Committee would address answers to some of the questions later in the day.
XIII Action Items (Cont’d.)
Dr. Peterson stated the next item on the agenda was to review potential safety issues associated with various options to address once-through cooling at DCPP.
D. Evaluation of Safety Issues (“Evaluation”) for Bechtel Power Corporation’s “Addendum to the Independent Third Party Final Technologies Assessment of Alternate Cooling Technologies or Modifications to the Existing Once-Through Cooling System for Diablo Canyon Power Plant Addressing the Installation of Saltwater Cooling Towers in the South Parking Lot.” (Bechtel Addendum)
Dr. Peterson reported that at the public meeting on August 8, 2014, the public had not been accorded sufficient time to review the Evaluation of the Bechtel Addendum and it was therefore determined by the Committee to defer consideration of the Evaluation to this public meeting. He stated the Bechtel Addendum was in draft form as of August 8, 2014, and it was determined to leave the Evaluation in draft form to allow more time for review but that the draft version of the August 8, 2014 Evaluation had been provided to the State Water Resources Control Board (SWRCB). Dr. Peterson noted that the effect of having the DCISC review a draft of the Bechtel Addendum resulted, with the permission of the SWRCB, in the Bechtel Addendum being made available to the public earlier that would have otherwise been the case.
Dr. Peterson stated that together with Consultant Wardell as the authors of the Evaluation changes were made to the draft Evaluation for the August 8, 2014 meeting after the meeting. Subsequent drafts were provided on August 11 and October 7. Dr. Peterson briefly described the process used by the Committee to prepare the Evaluation for consideration at the public meetings of August 8 and October 14, 2014, and he stated the original technologies assessment study by Bechtel (“Bechtel Assessment” on which the DCISC provided its review on September 4, 2013, addressed seven different options for changing DCPP’s once-through cooling system which would essentially attempt to filter or reduce impingement while maintaining the use of seawater for plant cooling and a variety of options that could potentially be implemented in order to use cooling towers in a closed cooling system. Dr. Peterson stated the DCISC concluded in September 2013 that all of the options presented by the Bechtel Assessment could likely be implemented without major impacts on plant safety but there remained key areas of uncertainty regarding their effect on plant reliability.
Subsequent to the release and review of the Bechtel Assessment comments were received including from the group Friends of the Earth (FOE) and Bechtel was directed by the SWRCB Review Committee for Nuclear Fueled Power Plants (RCNFPP) to perform a study of certain additional options which might reduce the cost of construction including moving the location of the proposed cooling towers from north of the plant site to the south, implementing the use of seawater as the coolant makeup rather than using desalinated and reclaimed water, and to change the cooling water temperature to permit the use of smaller cooling towers. Dr. Peterson observed there is a limit where if it were reached the water from the cooling towers would be too warm to be able to be used in the plant’s existing Service Cooling Water System (SCW) used to provide heat removal from a wide variety of non safety-related equipment. Therefore, if the cooling towers were made large enough it becomes possible to keep the existing SCW. With smaller cooling towers it would be necessary to build a small once-through cooling system for the SCW which would not require a complete change out of the SCW as the quantity of water needed for the SCW is quite small. Dr. Peterson stated none of the plans proposed for cooling towers at DCPP call for changing the use of seawater for the Auxiliary Saltwater System (ASW) which is a safety-related cooling load. Dr. Peterson remarked the principal purpose of the proposals to eliminate once-through cooling at DCPP is to reduce the total amount of water used to cool the plant by eliminating the use of seawater to cool the condensers which he described as having a very large thermal load.
Dr. Peterson observed that with reference to the Bechtel Addendum and the Bechtel Assessment there are various permutations of all the proposals which might be employed in various combinations. He stated Mr. Bill Powers, an engineering expert engaged by FOE, has also proposed locating the cooling towers at a higher elevation thereby reducing the amount of excavation required. Dr. Peterson stated the Evaluation included consideration of whether the proposed changes would require DCPP to obtain a license amendment from the NRC and in this respect the Evaluation disagrees with Bechtel’s position that the 10 CFR 50.59 process would be adequate to allow plant modifications but Dr. Peterson observed that only the NRC could make such a determination. Dr. Peterson stated that the implications of modifying the plant include assessment of the impact on a number of safety-related systems including the flooding analysis for the Turbine Building, analyzing the impact on the ASW and he stated that in DCISC’s judgment it is likely that the NRC would require a license amendment.
Dr. Peterson stated the potential impact of placing cooling towers to the south of the plant site involves the impact upon normal access and upon a number of plant support facilities that are now located in that area. He stated the southern option would have a larger impact upon plant operations than if the cooling towers were located to the north of the plant site. The Bechtel Addendum proposes that the majority of construction would occur during a 6.3—6.5 year period during which both units would remain in operation. The final connection of the cooling towers would require excavation within the protected area and temporarily disabling and rerouting the ASW and replacing the fuel storage tanks for the EDGs during a dual unit outage which would extend for 2.3 years.
Dr. Peterson observed the Evaluation did not address the cost estimates or the schedule but focused upon safety impacts on operations, emergency response, and security. He stated the closest analogy to what is proposed is offered by the security-related modifications to the plant which were undertaken after September 11, 2001, which the DCISC has closely followed. Dr. Peterson observed security and safety aspects can sometimes be in conflict as security involves limiting access while safety involves assuring access and egress. He stated DCPP has a process for reviewing the implications of such changes which includes creating temporary barriers to assess whether the restrictions proposed would cause problems related to operability or safety.
Dr. Peterson observed such a review for the modifications proposed in the Bechtel Addendum and Bechtel Assessment would be substantially more challenging but would be lessened if the cooling towers were located to the north of the plant site. The needs created by a southern siting for the cooling towers would also require changes to safety-related systems including installation of new cooling water ducts which enter the protected area from the south and create impacts on the design of the ASW, which is the primary safety-related heat sink, as well as on operability of the EDGs because of impacts on underground piping and the need to replace the underground diesel fuel storage tanks. Bechtel has also proposed replacement of the EDGs by temporary emergency diesel generators which would be challenging due to the fact the EDGs must be protected from external missiles and other threats. Dr. Peterson stated the Evaluation recommends a probabilistic risk assessment be done to quantify these potential impacts. He commented that there could be some positive impacts on plant safety and reliability through the installation of cooling towers including reducing or eliminating periodic problems which have occurred with circulating water pumps due to impingement on the Traveling Screen System which have now been addressed at DCPP by implementation of winter storm watches and the reduction of power during winter storms, thereby making the consequences of a plant trip less severe, as well as the installation of a bubble curtain to protect the Circulating Water System from intrusion by fish and sea life.
Dr. Peterson reported the Evaluation considered the potential safety impact of using seawater for evaporative cooling in place of fresh water. He reported a study by the CEC reviewed the use and effect of high salinity water used in cooling towers on accelerated corrosion on unprotected metal surfaces on buildings and equipment. This report concluded that nearly all plants with high salinity cooling towers, both natural and forced draft, have encountered accelerated corrosion. Dr. Peterson reported that use of saltwater cooling towers with drift elimination at DCPP is expected to release approximately 830 metric tons of salt each year in aerosol form and a key question involves where that salt will be deposited on the plant site. Dr. Peterson reported data shows that the majority of the time the wind would carry a plume from southern-sited cooling towers to the south and away from the plant but 11% of the time the wind would carry the plume to the north and over the plant, while 23% of the time the plume would be expected to rise in light to no wind conditions.
DCPP is once again collecting data on current salt deposition rates at various locations and it appears the current rate of deposition is approximately 1.5 or 2 metric tons per year. Dr. Peterson stated modeling tools could be used to develop more accurate projection for salt deposition which would be important tools in reviewing the impact on systems and equipment which use large volumes of air such as the EDGs, the ventilation systems, and the dry cask spent fuel storage systems as well as upon the reliability of high voltage equipment including the switchgear in the 230 kV and 500 kV Switchyards where a simultaneous failure would lead to a loss of offsite power. Dr. Peterson observed that most of the flashover problems experienced by U-2 appear to be associated with drift from the Outfall which is pulled by the wind between the Administration Building and the Turbine Building and the use of freshwater could reduce or eliminate that issue. Use of saltwater cooling towers could increase deposition rates substantially from the present and periods of adverse weather with higher deposition rates could increase flashover events and this is subject to analysis through modeling. Dr. Peterson stated the Evaluation reviewed the use of high salinity cooling towers by the Palo Verde Nuclear Generating Station (Palo Verde) in Arizona which uses reclaimed water from the City of Phoenix in a desert environment with different wind and humidity than at DCPP and Palo Verde produces a lower salinity release, containing approximately one-half the amount of salt that is forecast for DCPP if saltwater cooling towers were built. Dr. Peterson stated the Evaluation concludes that more study concerning the implications of using saltwater cooling towers is required.
Dr. Peterson reported the Evaluation reviewed the use of smaller cooling towers to reduce cost and address siting issues and determined their principal impact would be an additional derating of the plant’s power output and for the southern siting option the inability to modify the SCW and therefore a separate once-through system to provide water to the SCW would be required operating essentially as it does now, while circulating water that would go to the turbine condensers, the dominate use of cooling water, would be shifted to water from the cooling towers. He reported the Evaluation did not identify substantive negative impacts on safety from the various different impacts on condenser back pressure.
With reference to placing the cooling towers at a higher elevation, Dr. Peterson reported the principal impact would be on the pressures at which the condenser cooling water piping would operate together with an increased risk from leaks and flooding which should be studied and he remarked the DCISC has added entries to its Open Items List to review several of the items identified in the Evaluation including the current flooding design basis and how that might change and impact the Turbine Building and the EDGs.
Dr. Peterson summarized the recommendations from the Evaluation which include:
- Evaluating the impact of southern siting for cooling towers on plant security, emergency response and safety capabilities.
- Analyzing how extensive an NRC review might be necessary, specifically regarding the replacement of the ASW underground piping.
- Performing a probabilistic risk assessment to quantify the impact of cooling towers on the risk of transients and any reduction in safety margins.
- Evaluating the impact of salt deposition on various equipment including periods of adverse weather conditions.
Dr. Lam commented that Dr. Peterson and Consultant Wardell had performed a tremendous piece of work on an exceptionally tight schedule and this was accomplished within the requirements of California’s Bagley-Keene open meeting laws. Dr. Lam remarked that much more work needs to be done by Bechtel and he suggested that the title of the draft Evaluation be revised to indicate that the Evaluation was preliminary as the DCISC does not yet have enough information to reach a final determination and more observation and study is required.
Dr. Budnitz remarked the DCISC review of the Bechtel Assessment approved by the Committee at its meeting on September 4, 2013, concluded that more information was required to evaluate the seven options in the Bechtel Assessment but the DCISC review concluded that with more information if the design and safety analysis were done properly it was likely any one of those seven options would meet the NRC’s safety review criteria. Dr. Budnitz stated that the Evaluation of the Bechtel Addendum reviewed the use of cooling towers located on the south side of the plant and use of saltwater rather than fresh water for cooling and stated that it was his belief that if done properly either or a mix of those proposals could likely be licensed by the NRC. Dr. Budnitz observed that in its September 4, 2013 review of the Bechtel Assessment and in the current Evaluation of the Bechtel Addendum the criterion used by the DCISC was that any alternative proposal should provide at least approximately the same level of overall nuclear safety and any degradation of safety, even if the proposal met the NRC safety criterion, was unacceptable. Dr. Budnitz stated that some features of the newly proposed designs would likely improve safety by addressing problems with the existing once-through cooling system which, like all systems, has failure modes which produce the potential for accidents. If the replacement technology does not suffer from worse problems safety could be improved. Dr. Budnitz stated making such a determination requires analysis of a complex mix of frequencies and consequences of accidents and it is on that basis that the DCISC offers its recommendation that not enough design and analysis has been done to answer questions about the level of safety that would be achieved by the proposals provided in the Bechtel Assessment and Bechtel Addendum. Dr. Budnitz stated the DCISC in its reviews and evaluations did not address issues of cost or schedule except as insofar as scheduling issues could impact safety. He stated it is important to understand how nuclear safety analysts analyze the safety of a plant which is a different process than that used by the NRC to determine if a plant meets the minimum levels of safety necessary to obtain a license to operate. Dr. Budnitz observed all U.S. nuclear plants need to be better than the NRC licensing criteria and all the plants currently running exceed the NRC criteria. Dr. Budnitz remarked that when issues occur at DCPP such as the flashover events the report of those events is reviewed by nuclear operators around the world. Three events at DCPP involved flashovers in the last approximately two years and the DCISC believes that any new design must result in much fewer of these flashover events in order to be safer than at present. Before this can be determined more analysis is required to obtain an NRC license for a new design and even more analysis is required to determine if the new design would meet the DCISC’s safety criterion that the plant must remain at least as safe as it is now. Dr. Budnitz remarked there is a community of safety experts who would be involved in scrutinizing any proposed new design and this is a positive benefit for the analysis and ultimate determination concerning safety of the design proposals.
Dr. Peterson requested comments from members of the public.
Mr. Joey Racano representing the California Ocean Outfall Group was recognized. Mr. Racano stated the safety issues identified by the State of California are issues which the state wants to see DCPP follow through concerning and it is time to upgrade to the best available technology. He stated that the plant has intruded on the ocean environment and that if salt is a problem the plant should be removed from the coast where it would not need to use ocean water for cooling purposes. He observed DCPP is constructed upon faults and there is no reason for the plant to be so located, as doing so is dangerous as is anything which is proposed to extend the operational life of DCPP. He requested a few moments of silence in recognition of the 25th Anniversary of the Loma Prieta earthquake. Mr. Racano directed attention to the issue of what he described as en echelon faults which he stated are parallel faults which can interact to give vertical acceleration to seismic energy sufficient to overwhelm DCPP‘s safety features despite any retrofitting. He stated his group believes DCPP should be upgraded to the best technology and this should be done without the ocean intruding on the nuclear plant as it is only a matter of time until another earthquake similar to Loma Prieta occurs and such an event would be a calamity as there is an overabundance of nuclear waste stored at DCPP on earthquake faults.
Mr. Bill Powers, an engineer speaking on behalf of Friends of the Earth, was recognized. Mr. Powers stated that a comment letter he submitted to the Committee was in draft form and would be revised. He also remarked he misunderstood the concern expressed in the Evaluation concerning flooding. Mr. Powers stated his belief that the conclusion in the Evaluation that use of saltwater evaporative cooling by cooling towers located to the south of the plant would have a sufficiently negative impact so as they might not meet the DCISC safety criterion should be modified to recognize and reflect several other statements in the Evaluation that certain questions could not be answered due to lack of information, study and analysis and a reference to that additional study should be included in the Evaluation’s conclusion.
Mr. Powers reported he provided information to the RCNFPP regarding a Bechtel paper on seawater cooling which listed more than 30 operational reactors worldwide which use seawater cooling tower. Dr. Peterson observed that the issue involved the use of high salinity cooling water not necessarily seawater and that the issue of salinity in the Bechtel report was not well defined. Mr. Powers reported that the Hope Creek Nuclear Plant (Hope Creek) in New Jersey is slightly larger than the individual units at DCPP and uses a saltwater cooling tower located in the vicinity of the Hope Creek plant’s high voltage switchyard. He reported that since Hope Creek began operations in 1986 it has maintained a comparable overall operational capacity factor (98% for Hope Creek) to that of DCPP U-1 (92%) and U-2 (88%) and over the period 2010-2013 all three units are at 92%. Mr. Powers stated this represents a 28-year operational case study of a similar reactor to those at DCPP using a saltwater cooling tower located adjacent to the high voltage switchyard. Mr. Powers reported Florida Power & Light Company has applied to the NRC to build Turkey Point Units 6 and 7, which will be approximately the same size as DCPP and will use either reclaimed water or seawater with a slightly higher salinity than is proposed by Bechtel for DCPP. He remarked that in his opinion this demonstrates that there is no insurmountable safety issue related to seawater cooling.
Mr. Powers observed the Evaluation was somewhat selective in its use of conclusions from the 2010 CEC report and that this report includes other conclusions that utility size cooling towers have been designed, built and operated successfully using seawater and recent installations of mechanical draft cooling towers operating with high salinity using corrosion resistant material have operated successfully. He stated the cooling towers proposed by Bechtel for use at DCPP would be made of fiberglass and would not be expected to experience the degree of degradation experienced by cooling towers and basins constructed of concrete. He reported all studies reach the conclusion that there was no significant increase observed in salt concentrations in soils or vegetation in the vicinity of plants using high salinity towers and no symptom of environmental injury. He stated the 2010 CEC report was generally favorable to the use of seawater cooling towers.
Mr. Powers stated the arcing issues experienced by the DCPP transformers were caused by the impact of the higher salt deposition rate on U-2 due to prevailing winds taking spray from the once-through cooling Outfall between the Turbine Building and the Administration Building to the U-2 transformer area. He remarked that with the use of cooling towers the impact of salt deposition from the Outfall would be eliminated. Dr. Peterson stated there is a concern with the substantively greater amount of salt produced by the cooling towers and the current release from the Outfall is a more focused release. Dr. Peterson reported wind data shows that approximately 20% of the time the wind would carry the salt deposition from the cooling towers over the plant site and study using modeling is needed to determine how much of the salt would be deposited close to the cooling towers as opposed to elsewhere on the plant site. Mr. Powers agreed that more study is needed and commented the Evaluation did a superb job in demonstrating deposition tendencies at the plant. He stated that the U-1 transformers were not further away from the Outfall than the U-2 transformers and it was only the salt deposition rate due to wind patterns which was the cause of U-2 experiencing more events challenging its reliability. Mr. Powers stated in his opinion it was premature to conclude that salt deposition from cooling towers would be worse than that salt deposition currently experienced at DCPP originating from the Outfall and he asked that the Committee acknowledge this in the Evaluation. Dr. Peterson replied that the Outfall source is relatively small and focused on a limited area of the plant and it is necessary to consider other systems that do not now experience much salt deposition but might see significantly more if the use of cooling towers replaced the volume of seawater at the Outfall.
Dr. Peterson stated in anecdotal discussion it was mentioned that employees prefer not to park their cars near a cooling tower and Mr. Powers agreed that much of the drift which comes off a cooling tower is deposited in the vicinity of the tower. Mr. Powers stated it was estimated approximately 237 tons of salt would become airborne away from the immediate vicinity of the cooling towers. Mr. Powers stated he was in agreement with the DCISC that more modeling exercises are necessary but he differs from the Evaluation in that he does not believe that a safety determination can be made at present that salt deposition represents a definite negative impact from saltwater cooling towers. Mr. Powers stated the Evaluation has set the DCISC against Bechtel’s conclusion that the salt deposition issue is an operational and maintenance issue and he opined this is based on a wealth of information from Bechtel’s experience and he questioned how the DCISC could be in a position to question Bechtel given Bechtel’s experience in designing, building, and operating facilities which use saltwater cooling towers. Dr. Peterson observed it is difficult to make direct analogies between DCPP and other plants due to more complex wind patterns at DCPP as compared to other plants located in simple topography without proximity to mountains and the ocean. Mr. Powers stated he gives credit to the Evaluation for acknowledging that installation of seawater cooling towers could improve DCPP reliability by reducing trips associated with kelp if the Outfall were eliminated, which would also eliminate a prime source of problems for U-2.
Mr. Powers stated that the Evaluation conflicts with Bechtel’s assessment of whether a license amendment would be required and he remarked that in 2007 the CEC Independent Energy Policy Report included a nuclear workshop during which the then Acting Deputy Director for the NRC Division of License Renewal made the statement that use of cooling towers at DCPP represented a state issue under the auspices of the SWRCB and that the NRC would not be involved in making a determination of whether NRC regulations would preclude the use of cooling towers at nuclear plants, Dr. Peterson stated that there is likely more to the NRC role in that the NRC would be involved in the decision as to whether a licensee would be allowed to make the modification to use cooling towers and the NRC Acting Deputy Director may have been commenting in policy terms on a decision of once-through versus closed cooling. Dr. Budnitz stated he interpreted the then Acting Deputy Director’s comments as meaning the NRC would not intervene to tell the licensee or the licensee’s state regulator whether or not the NRC would insist on the change to cooling towers. Dr. Budnitz observed there are 40-50 nuclear plants in the U.S. which use cooling towers and it is clear that the NRC has a process to license the use of cooling towers but would not intervene in a decision to require their use but would review the change and the plans as the NRC would for any plant and if the NRC safety criterion was met a license could be issued which, Dr. Budnitz stated, is essentially consistent with the conclusion reached in the Evaluation. Dr. Lam remarked that before his retirement in 2007 he sat as a Federal Administrative Judge on the NRC’s Atomic Safety Licensing Boards and if this issue were before him in that judicial role, without commenting on the merits of an intervention petition, procedurally a back fit of the magnitude being proposed for DCPP would certainly require a public hearing. Dr. Lam stated he appreciated the comments offered by Mr. Powers and would consider and agreed to make changes in the preliminary Evaluation in response to Mr. Powers’ comments.
Mr. Powers again stated he misunderstood the concern expressed in the Evaluation about flooding but stated that flooding might not be an issue dependent upon the proximity of the cooling towers to the Turbine Building and he stated the cooling tower for U-1 is expected to be located 2,000 feet from the Turbine Building on a cliff over the Pacific Ocean, with the cooling tower for U-2 projected to be located somewhat closer to the Turbine Building, but any water with the potential to flood the Turbine Building should be precluded by engineering design. Mr. Powers remarked that concerns about the EDGs and the ASW would not be expected to affect plant reliability as those modifications would take place during the time both units would be off line and not operating.
In concluding his remarks, Mr. Powers again stated his belief that the Evaluation should include in its conclusion the statement that more study is required to determine if there are overall safety impacts which might not meet the DCISC safety criterion. Mr. Powers remarked that he saw no reason the cooling towers should be located at an elevation of 115 feet as both the existing duct work and condenser upgrade to 50 psig would provide adequate headroom to locate the cooling towers in the south parking lot without the need for significant excavation other than for the pipes going to and from the towers.
Dr. Budnitz remarked that SONGS is no longer running due to issues with the replacement of its SGs although there have been many other individual SG replacement projects and it might have been assumed that the engineering would be performed correctly but this turned out not to have been true and therefore attention needs to be paid and issues need careful further analysis.
In response to Consultant Wardell’s question Mr. Powers stated the Hope Creek plant was designed to use cooling towers and he was unaware of whether protective devices were designed for the high voltage switchyards at Hope Creek but he remarked the CEC has suggested a remedy for salt deposition by installing salt resistant insulators. Mr. Powers reported Hope Creek uses a hyperbolic tower which he presumed included use of a mist eliminator. Dr. Budnitz remarked the Hope Creek plant has protection for hurricanes. Mr. Powers stated he did not evaluate a wind rose diagram for Hope Creek. In response to Consultant Wardell’s inquiry, Mr. Powers stated he did not see security as a major issue with the transition to the use of cooling towers by DCPP but he agreed that a PRA analysis would provide more confidence in making a recommendation.
The Chair opened the floor to public comments.
Dr. Gene Nelson was recognized. Dr. Nelson stated that as DCPP was not broken and there was no need to fix it and the SWRCB actions were simply a disguised method to shut down nuclear power plants in California as nuclear plants have the greatest amount of waste heat to release to the environment and accordingly would require the most complex cooling systems. He observed that cooling towers which would increase salt deposition and their construction of fiberglass could result in a fire if the towers were targeted by terrorists. He remarked DCPP is 85 feet above sea level and unlike at Fukushima gravity would keep saltwater out of the plant’s safety-related systems but the SWRCB’s actions could result in a large amount of saltwater and brackish water becoming located above the 85 foot level. In summary, Mr. Nelson stated his belief that the SWRCB plan would create a potential for a man made tsunami at DCPP.
Ms. Rochelle Becker, representing the A4NR was recognized. Ms. Becker stated she sits on the RCNFPP and as a member of that Committee she requested that a satellite webcast location be established in San Luis Obispo for presentation of the Bechtel Addendum to the RCNFPP on November 18, 2014. Ms. Becker stated the CEC supports that request and she stated that it was important that the DCISC send representatives to the meeting as well as provide support for the request to establish a satellite location for a webcast of the meeting in the local area.
Dr. Henriette Groote was recognized. Dr. Groote remarked she was a supporter of MFP and A4NR and she complimented Dr. Peterson for a clear and lucid report on the Evaluation of the Bechtel Addendum. She stated she was unclear whether the Evaluation favored the northern or the southern location for the cooling towers and she inquired if the Evaluation considered that at some point there could be simultaneous interaction between the flooding and salt deposition problems. Dr. Budnitz responded that the Evaluation neither favors nor disfavors either site but merely evaluated the options and issues in connection with each location in accordance with the DCISC’s safety criterion but until more analysis is done the relative factors associated with each proposed site cannot be adequately evaluated. Dr. Peterson remarked that the use of freshwater would result in less salt deposition and the northern location in less disruption during the construction phase but whether those impacts are sufficient to affect a final decision is something that requires additional analysis. Dr. Budnitz observed the freshwater option would require construction of a very large and very expensive desalination plant but that matter was not one that involved nuclear safety.
Mr. William Gloege of Orcutt, California was recognized. Mr. Gloege remarked that a number of attacks have been made on DCPP’s operations including false reports that the plant was leaking radiation. Reports on the seismic faults in the vicinity of the plant have established that those faults are minor and do not have the capacity to create sufficient earth movement to damage the plant. He stated his opinion that the issue of cooling towers is part of a game to shut DCPP and that these actions have the potential to harm the environment because were DCPP to close more smoke, soot and ozone would be released into the air. Mr. Gloege remarked the DCISC deals with safety and should therefore consider the negative safety impact on human beings if the plant were to close as well as the impact of its closure on global warming issues. Dr. Peterson responded that the charter of the DCISC directs it to review and focus its attention on operational safety and the issues raised by Mr. Gloege fall outside its remit.
Mr. Damon Moglen, representing FOE and overseeing its program on DCPP, was recognized and was connected to the meeting by telephone. Mr. Moglen thanked the Committee for the opportunity to address the meeting. He commented he believed the concern expressed in the Evaluation with salt deposits on the spent fuel canisters was an oversight as there was no basis or references to documentation in support of that concern in the Evaluation and in his opinion the references to an impact on the spent fuel canisters should be removed from the Evaluation. Mr. Moglen observed that the Evaluation contained very little analysis of the problems which currently exist as a result of DCPP’s use of once-through cooling including the Outfall producing sediment which causes tripping problems. Mr. Moglen stated the Evaluation should clearly document that there are problems with the current cooling system, aside from the issues of entrainment and entrapment of sea life, which have an adverse effect on plant safety. Mr. Moglen commented that during the period when both reactors would be shut down there would be no issues of plant operational safety aside from maintaining water to the SFPs and he commented there is experience with large scale projects concerning replacement of the SGs and the reactor vessel heads which might be more relevant than the efforts to address post 9-11 security issues. Mr. Moglen observed in its earlier Evaluation of the seven technologies addressed in the Bechtel Assessment the DCISC did not identify issues in accordance with its safety criterion in connection with the wedge-wire screen proposal which he stated would create entrapment problems but the Evaluation of the Bechtel Addendum now raised potential safety problems with the southern siting proposal without using the same criterion and he encouraged the DCISC to take an even-handed approach concerning its assessment.
Ms. Sherry Lewis representing MFP was recognized. Ms. Lewis stated dry cask storage should not be an issue as its duration extends beyond the operational life of the plant and she observed that over time salt deposition would be expected to occur on the canisters without cooling towers and she stated her opinion that this factor needs to be taken into account. Dr. Peterson noted the Committee has added an item to its Open Items List to address salt transport and its potential effect.
Dr. Budnitz, in response to Mr. Moglen’s comments, remarked that installation of the cooling towers was projected to take more than six years during which both units would remain in operation followed by two years of a dual unit outage. Dr. Budnitz stated that in his opinion it was likely the NRC would require a full core offload to the SFPs for the two-year dual outage rather than leaving the cores in the reactor vessels and, if that were the case, there would be little risk of problems with the reactors while no fuel was present in the core and accordingly no nuclear safety issues with the reactors and the vessels would be available for extensive inspection. In the alternative, the cores might remain within the vessels and the SFP inventories would consist of older assemblies while cooling would have to continue to the reactor vessels as well as to the SFPs.
Ms. Carole Hisasue, a resident of Los Osos and member of MFP was recognized. Ms. Hisasue read a statement by Ms. Jane Swanson, spokesperson for MFP. In the statement Ms. Swanson stated her belief that the Evaluation inadvertently left in place two references to potential salt damage to the spent fuel casks from salt deposition without including evidence on this issue and those references should be deleted from the Evaluation. Dr. Peterson replied the statements referred to by Ms. Swanson would remain part of the Evaluation based upon an understanding that use of saltwater cooling towers would very likely significantly increase the rate of salt deposition at the Independent Spent Fuel Storage Installation (ISFSI) but would consider modifying the recommendation to make it clear the Evaluation was not reaching a premature conclusion on the potential safety effect of salt deposition and that modeling analysis on this issue should be done. Dr. Peterson commented new issues have also arisen with regard to the potential for hydriding and embrittlement of fuel cladding as a consequence of the manner in which the spent fuel canisters are dried and packed which the DCISC will review. Ms. Hisasue commented the SWRCB has determined that the cooling towers are needed by 2015 as once-through cooling is harming the marine environment and the only responsible thing to do is to shut down DCPP until the towers are built both during construction and connection of the towers. She stated that after listening to the presentation she understands that determining the type of tower to be used will take time as there are safety issues involved and this assessment will be very expensive and the cheapest option for both PG&E and its ratepayers would be to shut down the plant and replace it with a clean energy power plant as nuclear power is not green power and radiation can be lethal.
Mr. Joe Olveira, a resident of Orcutt, California was recognized. Mr. Olveira observed the state is very short of fresh water and PG&E has been studying the effects of once-through cooling at DCPP for many years and he commented it was important in this matter to be logical and focused upon science and engineering. Dr. Peterson stated the DCISC Charter would not permit the Committee to judge whether the environmental impact of once-though cooling or that of the cooling towers was necessary.
Ms. Simone Malbouef was recognized and stated she was speaking in support of requiring PG&E to comply with the State Marine Environmental Protection Policy of 2010. She reported on September 25, 2014, the local newspaper ran an article by former NRC Senior Resident Inspector Dr. Michael Peck and she read from that article Dr. Peck’s description of the process used to evaluation his differing professional opinion concerning nuclear safety issues with reference to the NRC standards used to evaluate DCPP’s safety based upon Dr. Peck’s perception that its regulatory seismic design basis margins had eroded but which resulted in no change in the NRC’s conclusion that DCPP could continue to operate in accordance with its operating license. Ms. Malbouef stated the duration of the process outlined for the installation of cooling tower, which she stated would take 21 years, would extend beyond the plant’s currently licensed operational lifetime. She further stated that the controversy over the seismic faulting at the plant site would also need to be assessed as to its effect on undermining safe operation of DCPP. Ms. Malbouef stated an engineer at the Fukushima nuclear plant attempted to report defects and cover ups at that plant to the Japanese government and the engineer has reported nuclear power is unstable and therefore unsafe and nuclear accidents are bound to occur and have occurred three times in our lifetime. She stated she joins in opposing the continued proliferation of nuclear power and supports the shut down and closure of DCPP.
Ms. Linda Seeley was recognized. Ms. Seeley stated she was representing MFP and stated PG&E should be viewed in a cautionary light. She stated PG&E employees were extremely conscientious but the corporate culture was suspect. She stated her opinion that PG&E commissioned Bechtel to perform an assessment of alternatives to once-through cooling so that the report would indicate an excessive cost and it was FOE that reviewed the report and identified less costly alternatives. Ms. Seeley reported PG&E has been fined for its role in causing the gas transmission explosion in San Bruno, California which resulted in eight deaths and the destruction of 38 homes and PG&E has recently been found to be complicit by having an improper relationship with the staff of the CPUC which resulted in the resignation of the CPUC President and PG&E is under investigation for improper communication with NRC staff based upon its release of the report on the Shoreline Fault at the same time as the NRC release of its final determination of Dr. Peck’s concern. Ms. Seeley advised the DCISC that PG&E might be using the DCISC for its own purposes and the DCISC could be an unwitting victim of another allegation of PG&E engaging in collusion. She closed her comments by stating it was her hope that the Evaluation would be modified in response to the comments made by Mr. Powers. In response to Dr. Budnitz response for clarification of her comments, Ms. Seeley stated she believed the DCISC could be duped by PG&E to advance PG&E’s profit motives and the DCISC is advancing PG&E’s interests by raising safety concerns with the cooling tower proposal which are not based upon good science and she stated it was her impression the Evaluation included conclusions based upon allusions. Dr. Lam commented that he found some of Mr. Power’s comments persuasive and could support some but not all of Mr. Power’s comments. Dr. Budnitz commented the DCISC is not concerned about how the proposal to install cooling towers would be paid for, whether by PG&E or by its ratepayers, as that was not within the DCISC’s remit. Dr. Peterson observed some of the FOE recommendations involve design changes to the plant which the Evaluation concluded would likely not have safety implications for the plant but the use of saltwater and the issue of operating the plant during a protracted construction period does raise important questions which could involve substantive impacts on plant safety.
Mr. Steve Cleaver was recognized. Mr. Cleaver stated he is a local physics educator. He stated he believes that the issues reviewed by the Committee go beyond operational safety concerns but he recommended the Evaluation be clarified to include the clear recognition that there is a huge amount of uncertainty concerning the safety impact of the proposals discussed. The Committee responded that the Evaluation includes the statement that absent additional experiments, analysis and measurement not as much is known as needs to be and even when that analysis has been completed there will remain a certain amount of uncertainty regarding the safety implications of the changes proposed. Mr. Cleaver observed that when the Evaluation is approved, it will be used by a number of persons whose only purpose is to advocate shutting down DCPP.
Mr. Hector Garcia was recognized. Mr. Garcia stated he and his family are local residents and he is employed by PG&E as an engineer. Mr. Garcia stated the plant is very safe and has been so since the 1980's and that he would not want his family to live in the local area were that not the case. He stated his opposition to the installation of cooling towers is based upon proven evidence of the plant’s reliability.
Dr. Peterson expressed the Committee’s appreciation for the comments by members of the public and he apologized to the PG&E personnel who were in attendance expecting to present reports to the DCISC as the Committee had required more time than expected to entertain public comment. Dr. Peterson stated there was a consensus of the membership that the Evaluation should be modified and labeled as preliminary due to insufficient information in certain respects to reach conclusions about the safety impacts of closed cooling and accordingly the need for more study. Dr. Peterson stated the recommendations in the Evaluation should be modified to make clear that more study is required on the use of saltwater and that more study and modeling is required concerning the matter of salt deposition that would be expected on different areas of the plant including a comparison of the use of saltwater compared to freshwater for closed cooling with the continued use of the Outfall for once-through cooling. Dr. Peterson observed the Evaluation should be revised to also address the possibility that a probabilistic risk assessment (PRA) might determine that the overall reliability of the plant would increase or decrease as a consequence of the changes proposed and further study in this regard is needed. Dr. Lam stated that the first five pages of Mr. Powers’ comment letter appeared to be consistent with Dr. Peterson’s observations. Dr. Budnitz remarked the recommendation concerning the PRA analysis need only be revised to indicate that the analysis should quantify any change in the margins of safety and the reference to the higher salt deposition rates producing a negative impact on the ISFSI and spent fuel casks modified to indicate these impacts are likely to be less than the impact on the reactors. Dr. Budnitz stated the references to the consideration of the requirement for a license amendment should remain a part of the Evaluation as this matter would only be determined by the NRC following an extensive and involved public hearing process. The Members discussed the process to make changes to the Evaluation before its adoption and directed Consultant Wardell to revise the Evaluation in view of the public comments and the Committee’s discussion and direction and provide a revised Evaluation, including a version which shows the proposed revisions, for the Committee’s consideration later during this public meeting. The Chair also directed that a letter be sent to the SWRCB in support of the establishment of a satellite location in San Luis Obispo to permit members of the local community to observe and possibly take part in the deliberations of the SWRCB on November 18, 2014. The discussion of this matter closed with the observation that when approved the DCISC Evaluation of the Bechtel Addendum is due to be submitted to the SWRCB on or before November 4, 2014.
A short break followed.
XIV Information Items Before the Committee
The Chair requested Mr. Cary Harbor, DCPP Director of Compliance, Alliance and Risk to introduce the first of the informational presentations requested by the Committee for this public meeting. Mr. Harbor remarked that PG&E welcomed the previous dialogue between the DCISC and the members of the public concerning safety and he stated from PG&E’s perspective nothing is more important than the safety of the general public. Mr. Rathie reported that Mr. Wardell would be providing individual emails to each member later this evening with the revised draft Evaluation of the Bechtel Addendum and in accordance with the process for completing the evaluation all comments on the revised draft should be provided by Members individually to Mr. Wardell.
Mr. Harbor introduced Mr. Kevin Braico, Mechanical Design Engineer at DCPP and stated Mr. Braico has a degree in Mechanical Engineering and five years of nuclear experience.
Buried Pipes and Tanks Program.
Mr. Braico stated the core purpose of the Buried Piping and Tanks Program is to provide increased assurance of structural and leakage integrity of buried piping and tanks. Special emphasis is placed on safety-related systems and those tanks and piping containing licensed material or environmentally hazardous material. He reported DCPP has a relatively limited amount of buried piping on site compared to others in the industry and this provides DCPP with the ability to place special emphasis on opportunities to inspect its piping and tanks. Opportunistic inspections are utilized in addition to the required inspections to enhance reliability. Mr. Braico stated DCPP’s Buried Piping and Tanks Program has been reviewed and inspected by the NRC using the NRC’s Temporary Instruction Inspection 2515/182 protocol entitled “Review of the Implementation of the Industry Initiative to Control Degradation of Underground Piping and Tanks.” The last inspection was conducted in July of 2013 and no findings were identified.
Mr. Braico explained buried piping and tanks are below grade and in direct contact with the soil or concrete while underground piping, while it may be encompassed by buried piping, consists of piping and tanks that are below grade but are contained within a tunnel or vault such that they are in contact with air and are located where access for inspection is restricted. He stated he would cover both types in his presentation.
Mr. Braico reported in 2009 the US nuclear industry committed to implement an industry initiative to manage buried piping integrity designated as NEI 09-14, “guideline for the Management of Underground Piping and Tank Integrity.” He stated the Electric Power Research Institute (EPRI) hosts Buried Piping Integrity Group (BPIG) meetings twice a year to discuss: industry operating experience; monitoring equipment; inspection technologies; repair options; new materials; and research results. Representatives of INPO and the NRC, as well as the vendors who provide services for maintaining reliability, attend these meetings.
Mr. Braico displayed a map of DCPP indicating locations of its 21 miles of buried piping and 1 mile of underground piping and 2 buried tanks (there are no underground tanks) including the Auxiliary Saltwater System (ASW), emergency diesel fuel oil, firewater. In response to Mr. Linnen’s inquiry, Mr. Braico replied other nuclear plants may have three to four times the amount of buried piping as is installed at DCPP. He displayed graphic schematics of the individual systems and discussed and described the scheduled inspections completed including:
- Auxiliary Saltwater—from the Intake Structure to the Turbine Building consisting of 3,000 feet of buried piping per unit which uses cathodic protection and is constructed of carbon steel with PVC internal line and an epoxy outer coating. He reported the southern portion of the ASW piping was replaced in 1997-1998 to remove all piping from the tidal zone elevation. The piping is also inspected by video crawler during every fourth refueling outage and was last so inspected during 2010 and 2011. In response to Dr. Peterson’s request Mr. Braico stated the replacement of the southern portion of the piping was motivated by its location being too close to the tidal zone resulting in its submergence in saltwater and corresponding increases in corrosion rates. The piping was abandoned in place and new piping constructed at a higher elevation. In response to Dr. Peterson’s inquiry, PG&E’s Mr. Jearl Strickland replied he was responsible for the ASW bypass project and the replacement was initially conducted under the 10 CFR 50.59 process but, because the types of thrust blocks which were used required analysis techniques which differed from the analysis previously used by the NRC, a license amendment was required for the replacement of the ASW piping. Dr. Peterson observed that experience essentially resolves the issue of whether the installation of cooling towers would require DCPP to obtain a license amendment from the NRC and validates the DCISC’s position concerning the matter. In response to Dr. Lam’s question, Mr. Braico stated the NEI and EPRI industry initiatives function essentially as regulatory guidance for license renewal and were created so that plants would have a common goal and common path to managing buried piping and the NRC was consulted to ensure it was agreeable to the industry initiative.
- Diesel Fuel Oil—including the underground transfer piping running along the Turbine Building which runs within a trench and is covered with a steel or concrete plate, covering and the diesel fuel pump vaults located within buildings, and the piping that transfers fuel oil to the buried diesel fuel oil tanks. This system consists of approximately 1,500 feet of underground piping and Mr. Braico reported both diesel fuel oil tanks were upgraded and replaced in 1996 and 1997 with triple-walled tanks. Monthly inspections are made of the tank vaults and there is an active link as well which monitors inside the tank vaults, transfer piping, and the pump vaults. In response to Dr. Peterson, Mr. Braico confirmed DCPP has the capability to inspect all of its diesel fuel supply piping. He reported every 10 years an advanced inspection is performed which includes removing the tank, transfer pump and pump vault covers and doing a thorough inspection for corrosion or leaks. Personnel also physically inspect the inside of the diesel fuel oil tanks.
- Firewater—Mr. Braico stated the Firewater System is separated into two sections with the primary system consisting of approximately 7,300 feet of buried piping constructed of cement or PVC pipe to support the plant and connects to the Turbine Building, the Auxiliary Building, and other facilities in the area. Metallic components of the Firewater System consist of risers and valves which are generally encased in concrete which he stated results in a very low corrosion type of piping system. The Firewater System is inspected on an opportunistic basis and Mr. Braico stated the main source of degradation is from heavy loads resulting in collapsing the concrete piping. Dr. Peterson observed that following the Kashiwazaki-Kariwa earthquake in Japan in 2007 buried piping mounted to the foundations of buildings survived but underground or buried piping in the soil was broken due to soil movement but he remarked it was his understanding that none of the firewater piping outside of buildings at DCPP is nuclear safety-related. Mr. Braico stated that the system is designed so that failure in one section can be addressed by rerouting piping in other directions. Dr. Budnitz confirmed that firewater systems were not classified as safety-related but do support an important aspect of safety at nuclear plants.
Mr. Braico reported scheduled inspections are made of the ASW piping system, the diesel fuel oil piping system, hydrogen and nitrogen piping systems, as well as the laundry drain, and these are in addition to opportunistic inspections of the firewater, domestic water, and sewer piping. He stated the Buried Piping and Tanks Program is a priority-based program, developed and implemented throughout the industry. A database was compiled of all buried piping and tanks parameters (i.e. material, coatings, external environment, internal fluid, consequence of failure, and inspection results). This information is used to determine the likelihood of degradation and the consequences of its failure. The combination of the likelihood and consequences combine to form the priority ranking of the piping and allow focused efforts on the most significant piping. Mr. Braico stated that, in general, DCPP has a limited and well designed, Buried Piping and Tanks Program which has resulted in primarily low to medium priority results. Only one system is considered high priority and that is the ASW discharge piping and there the focus has been on the discharge piping as it leaves the Turbine Building and extends to the ocean, which portion is located within the soil and there will be a new system designed and installed as a result of inspection, while the remainder of the ASW discharge piping is protected by being encased in concrete.
In response to Dr. Budnitz’ request Mr. Braico stated he meets at least twice each year with his peers at other nuclear power plants to discuss piping inspections and results and the STARS Alliance (STARS), a joint nuclear utility initiative, facilitates a monthly teleconference concerning coordinating efforts and providing information on buried piping issues for its members. In response to Dr. Lam’s question, Mr. Braico stated opportunistic inspections can occur when a design change is being implemented or other work is in progress in the field which may involve excavation and provide an opportunity to observe piping.
Ms. Sherry Lewis was recognized. In response to Ms. Lewis inquiry Drs. Budnitz and Peterson replied firewater is used to extinguish fires and that some, but not all, of the underground below-grade piping can be accessed while buried piping inspection opportunities are much more limited. Mr. Braico replied underground piping is located in a vault or a trench, generally has a leak detection system installed, and is covered with steel or concrete plating which requires a crane to lift. Piping that is part of a daily walkdown inspection is not considered to be underground or buried piping.
Mr. Harbor introduced DCPP Manager of Regulatory Services Thomas Baldwin and reported Mr. Baldwin has more than 30 years’ experience in the nuclear industry and holds a Bachelor of Science Degree in Mechanical Engineering and has worked in leadership roles at DCPP in Engineering and Regulatory Services and also holds a Senior Reactor Operator License.
Review of NRC Performance Indicators, Licensee Event Reports & NRC Notices of Violations
Mr. Baldwin reported his presentation would cover the time between June 2014 and September 2014, particularly in the area of NRC oversight. He stated in summary all NRC performance indicators meet NRC green performance expectations. Two violations of very low safety significance were reported since the last DCISC meeting. He stated his presentation would cover more than four months of NRC inspections involving 2000 hours by both on site and specialized inspectors.
Mr. Baldwin reviewed two slides with a chart which summarized the NRC Performance Indicators that all nuclear stations report about every quarter. Mr. Baldwin stated that DCPP continues to meet all NRC performance indicator thresholds and sets more rigorous thresholds for the Performance Indicators than the thresholds set by the NRC and monitors those on a continuous basis in order to enter areas of declining performance into the Corrective Action Program before they can impact the performance on the NRC indicators. The NRC Performance Indicators, which are also available to members of the public on the NRC’s website, include:
- Unplanned Scrams per 7000 Critical Hrs.
- Unplanned Power Changes per 7000 Critical Hrs.
- Unplanned Scrams with Complications
- Safety System Functional Failures
- Mitigating Systems Performance Index, Emergency AC Power System
- Mitigating Systems Performance Index, High Pressure Injection System
- Mitigating Systems Performance Index, Heat Removal System
- Mitigating Systems Performance Index, Residual Heat Removal System
- Mitigating Systems Performance Index, Cooling Water Systems
- Reactor Coolant System Activity
- Reactor Coolant System Leakage
- Drill/Exercise Performance
- ERO Drill Participation
- Alert & Notification System
- Occupational Exposure Control Effectiveness
- Radiological Effluent Occurrence
Mr. Baldwin reported on the single Licensee Event Report (LER) initiated and issued by DCPP over the last several months as follows:
- LER 2-2014-001, issued July 2, 2014, Lightning Arrester Failure Resulting in Reactor Trip. Mr. Baldwin reported this event occurred in February 2014 and was reported as an LER in July 2014 for failure of a U-2 lightning arrester which caused the output of the station to be redirected through the failed arrester to ground. Plant protection systems detected the event and automatically actuated and separated U-2 from the grid and tripped the turbine which, with U-2 at 100% power,caused an automatic trip of the reactor. Mr. Baldwin stated all systems worked as designed. The failed lightning arrester was removed but because of the extensive damage it was not possible to definitively identify the cause of its failure and corrective actions are being taken to address possible causes. These corrective actions include shutting down each unit approximate every 90 days to wash salt and dust buildup on the insulators. Mr. Baldwin commented washing normally occurs during regular rainfall but the area is currently in a drought. In response to Mr. Linnen’s inquiry, Mr. Baldwin confirmed that DCPP is reducing power for both units as salt and contaminants build up on insulators for the units although the flashover events have occurred only on U-2. He responded to Mr. Linnen’s question by stating that compared to other nuclear plants DCPP experiences extremely heavy buildup of contaminants. He reported DCPP is procuring larger insulators which will provide the lightning arresting function but will not be as vulnerable to conductive buildup of contaminant. Mr. Baldwin reported additional quality controls are being employed in connection with this procurement.
Mr. Baldwin reported on two violations received from the NRC3as follows:
- NCV (“Green”—Failure to follow Procedure Associated with Seismically Induced System Interactions (C-C Aspect P.1 Identification). This violation was identified by the NRC during a walkdown when temporary or portable material and equipment, including a steel cart, a loose valve cap, and a guardrail that could potentially interact with permanent equipment were identified as unsecured or improperly positioned. Mr. Baldwin reported the Seismically Induced Systems Interaction Program is designed to address these types of issues and provides instructions and controls to protect plant equipment and deviations from procedural requirements were identified in connection with this violation.
- NCV (“Green”)—Inadequate Design Control with Respect to Seismic Induced System Interaction of Safety Related Components (No CC Aspect). Mr. Baldwin described this violation as similar to that discussed above. It was identified by the NRC from an observation atop a heat exchanger when a small gap was identified between a vent on the heat exchanger and structural steel in too close proximity to the heat exchanger which was not in accordance with DCPP design requirements for maintaining minimum distances between equipment to prevent the items coming into contact with each other. A portion of the structural steel was cut away to avoid the interaction and it was determined that had contact occurred the heat exchanger would have met all design requirements and remained capable of performing its function. In response to Consultant Linnen’s query, Mr. Baldwin replied the NRC inspectors typically are observant when in the plant for loose materials or improperly secured temporary equipment but climbing on to a heat exchanger is unusual and he characterized the discovery as a happenstance observation.
Mr. Baldwin summarized and reviewed the NRC inspection reports issued during the period of his report:
- Emergency Preparedness Annual Inspection Report (2013-502, 7/17/14) which found the Emergency Preparedness Program to be effective.
- Mid-Cycle Assessment Letter for DCPP (2014-006, 9/2/14) which found DCPP’s performance remains acceptable.
- Integrated Inspection Report (2014-003, 8/8/14)
In summary, Mr. Baldwin reported all NRC performance indicators continue to meet NRC green expectations. Cross-cutting performance is strong, with no cross-cutting themes or developing trends identified.
In response to Dr. Budnitz inquiry regarding a report on an unanalyzed condition with reference to humidity which could be caused around the 4 kV electrical busses due to a high energy line break, Mr. Baldwin stated the situation involved a discovery that equipment in the room had not been qualified or documented to be able to perform its function in high humidity conditions. The ventilation dampers from the area on top of the turbine deck were closed to prevent steam from entering the room and the equipment was sent to a test lab for evaluation and the equipment subsequently qualified to perform its function in the high humid condition and this event report was subsequently retracted.
Ms. Rochelle Becker of the A4NR was recognized. Ms. Becker stated that the Office of the Inspector General for the NRC issued a report concerning the SONGS steam generators which found the replacement of the steam generators at that plant should have been done pursuant to a license amendment request (LAR). She posed the question to the DCISC and to PG&E concerning the problems with the NRC’s process, which it had not admitted to, resulting in the SONGS ratepayers investing $670,000,000 into the steam generators. She inquired if there were any changes contemplated by PG&E to be made under the 10 CFR 50.59 process which would permit the public to have more faith that the NRC would actually follow its own criteria so that Californians may judge whether these are good investments. Dr. Budnitz stated that he received the report of the NRC Inspector General and would review it.
XV Adjourn Afternoon Meeting
The Chair adjourned the afternoon meeting of the Committee at 5:25 P.M.
XVI Reconvene For Evening Meeting
Dr. Peterson convened the evening meeting of the DCISC at 5:40 P.M. He introduced the other Members and welcomed members of the public present in the audience and those following the meeting by the streaming video available through a link on the Committee’s website at www.dcisc.org or at www.slospan.org
XVII Committee Member Comments
There were no comments by Committee members at this time.
XVIII Public Comments and Communications
Dr. Peterson inquired whether any member of the public wished to comment or address the Committee on matters not appearing on its agenda for this meeting.
Dr. Gene Nelson was recognized. Dr. Nelson stated he wished to repeat his earlier statement concerning the proposal to eliminate once-through cooling with closed cooling at DCPP. Dr. Nelson stated he is a resident of San Luis Obispo, California, and serves on the Physical Sciences Department at Cuesta College and has taught at Cal Poly. He stated the matter before the SWRCB is a disguised means to shut down nuclear power in California. As nuclear plants produce the greatest amount of waste heat they require the largest and most complex cooling systems. Unlike Hope Creek, the closed cooling system for DCPP would have to be applied as a retrofit and would compromise the long term safety of the plant due to the increase in the amount of salt produced. Dr. Nelson stated PG&E located the plant 85 feet above sea level and the proposal before the SWRCB would result in large amounts of dangerous salt and brackish water being placed above the 85 foot level with potentially disastrous consequence. He stated the proposal would create a potential man-made tsunami and cooling towers constructed of fiber reinforced plastic towers and although they offer greater resistance to salt they would be far more flammable than reinforced concrete towers which suffer degradation from exposure to salt. He closed his remarks by stating his opinion that the proposal before the SWRCB to convert DCPP to the use of closed cooling is a disaster waiting to happen.
Mr. William Gloege, a resident of Orcutt, California was recognized. Mr. Gloege stated the DCISC has a responsibility for the safety of human beings and it is legitimate to look at the impact on the safety of the population if DCPP were to shut down. He stated his opinion that the DCISC is defining its safety role too narrowly and DCPP was producing and protecting the safety of the air. He urged the DCISC to reconsider and widen its mandate to review the safety of human beings in relation to DCPP and to the potential effects of shutting down the plant. Dr. Peterson responded that in order for the DCISC to remain effective it is important that it focus exclusively on the operational safety of DCPP. Dr. Peterson stated the DCISC takes no position on whether the plant should operate or whether the license from the NRC should be extended as those issues represent policy decisions. The role and function of the DCISC should be to ensure that the plant is operated in the best manner and remains among the top rated nuclear power plants in terms of its operation.
XIX Information Items Before the Committee (Cont'd.)
The Chair requested Mr. Cary Harbor, Director of Compliance, Alliance and Risk at DCPP, to continue with the informational presentations by PG&E. Mr. Harbor introduced Mr. John MacIntyre, Director of Maintenance Services at DCPP and stated Mr. MacIntyre would be presenting tonight in place of DCPP Operations Services Director Jan Nimick. Mr. Harbor stated Mr. MacIntyre has more than thirty years of experience in the nuclear industry and holds a Bachelor of Science Degree in Nuclear Technology, a Senior Reactor Operator License, and has served in leadership roles in the Quality, Operations and Maintenance organizations.
Presentation on the State of the Plant Including Key Events, Highlights and Station Activities.
Mr. MacIntyre reported the NRC licensed operator examinations conducted on August 27, 2014, for 12 Operations license candidates resulted in 7 reactor operators and 5 senior reactor operators successfully completing their initial NRC examinations. This evaluation consisted of a written exam, a series of dynamic simulator exams, and a series of Control Room in-plant and administrative job performance measures.
Mr. MacIntyre stated PG&E released its Advanced Seismic Study on September 10, 2014. He stated this research confirms earthquake safety at Diablo Canyon. Dr. Budnitz confirmed that the Committee would be receiving a presentation on the Advanced Seismic Studies following Mr. MacIntyre’s presentation.
Mr. MacIntyre reported the NRC Problem Identification and Resolution (PI&R) inspection was conducted on September 11, 2014, to review the effectiveness of the plant’s Corrective Action Program and he summarized the results and findings from that inspection as follows:
- 3 Proposed “green” Non-Cited Violations (NCVs)
- DCPP has a strong Corrective Action Program
- No challenges to Safety Conscious Work Environment
- Use of operating experience is very good overall
- Good inspection with commendable results
In response to Mr. Linnen’s question, Mr. MacIntyre stated the PI&R inspection uses a series of interviews with individuals and teams to assess, both vertically and horizontally within the organization, and to reach an overall conclusion concerning safety conscious work environment attributes and he described it as a very thorough process.
Mr. MacIntyre provided a report and update on the current status of both units as follows:
- Station Update—Unit 1
- 500 kV Lightning Arresters Cleaning—reduced power and separated from transmission grid. Completed on September 6, 2014. Targeting replacement with new design in December 2014. Mr. MacIntyre stated both units have been off line approximately every 90 days for cleaning as a result of flashover events on U-2 which resulted in unit trips. A root cause evaluation has determined the design requires upgrading to prevent failure and improve overall station safety. Previously installed lightning arresters used ceramic bushings which produced shrapnel upon their failure and those bushings have now been replaced with polymer bushings and, subsequent to another failure, the polymer bushings were upgraded to a design adapted for a greater incidence of contamination which at DCPP is produced by it marine environment, diesel generator exhaust, and dust from construction activities. Since this upgrade a subsequent failure has occurred and the plant instituted the current cleaning regime to address the problem until yet another design is installed. U-2 will receive the newly design bushings during its current refueling outage and U-1 will receive them during the next scheduled cleaning. Mr. MacIntyre reported that by December 2014 both units will have been upgraded with what he described as new old-style ceramic lightning arresters. He confirmed Dr. Peterson’s observation that the problem of excessive buildup of contaminants is partially due to the current drought conditions.
- Station Update– Unit 2
- 500 kV Lightning Arresters Cleaning. Reduced power and separated from transmission grid Completed on July 19, 2014.
- Forced Outage—on August 14, 2014. U-2 experienced a forced outage as a result of maintenance work scheduled on its EDGs EDG 2-2 was out of service for a planned Maintenance Outage Window (MOW). Work was complete on EDG 2-1 and was in the process of being completed on EDG 2-2 when a failure mechanism was identified on EDG 2-3 due to a cap screw holding an injector to a fuel rack on the generator. U-2 was shut down to repair EDGs 2-2 and 2-3. A full Extent of Condition review using ultrasonic testing to inspect the cap screws was performed on all the other EDGs. All were found to be satisfactory and this issue was confined to EDG 2-3. However, as EDG 2-2 and 2-3 were both inoperable U-2 was placed in a very short shut down action situation. As repairs were being completed to EDG 2-3 and refueling was underway a leak occurred on the fuel pump which required the fuel tank to be drained again and this extended the time to complete the maintenance on EDG 2-3. With two inoperable EDGs U-2 was required to shut down to complete maintenance on EDGs 2-2 and 2-3.
Mr. MacIntyre reported U-2 entered a refueling outage on October 5, 2014. He described and discussed the major scope and performance goals for the work to be performed during the outage as follows:
- Primary Scope:
- Steam Generator sludge lance / eddy current testing (4 S/G’s)
- Reactor Coolant Pump (RCP) 2-2 motor overhaul
- RCP 2-3 seal package
- Containment Fan Cooler Unit (CFCU) inlet damper modification
In response to Dr. Peterson’s inquiry, Mr. MacIntyre reported approximately three pounds of sludge was removed from each steam generator which he described as a very positive indication of plant chemistry.
- Secondary Scope:
- Circulating Water Pump 2-2 Motor overhaul
- Turbine extraction steam bellows replacement—Phases A, B & C
- 480 V bus G breaker replacement—56 breakers
- 500 kV switchyard relay and breaker upgrades
- Battery and DC panel 2-2 replacement
- Lightning Arrester replacement
- Performance Goals:
- Recordable & Disabling Injuries 0
- Nuclear Safety Events 0
- Human Event Site Clock Resets 0
- Outage duration (days) ≤ 33
Mr. MacIntyre reviewed and briefly discussed upcoming activities for U-1 as follows:
- 21G1 Generator Backup Alarm Relay Replacement
- Repair North East Condenser Salt Leak
- 500 kV Lighting Arresters Replacement
Following the conclusion of his presentation, in response to Dr. Lam’s question, Mr. MacIntyre replied that in his position at DCPP he is focused upon equipment reliability and performance concerns and it is his expectation that maintenance on equipment and design modifications will result in excellent operational reliability. He remarked the PI&R process which he discussed in his presentation is used to evaluate failures and put processes in place to improve performance and has been successfully implemented to address a number of issues around equipment reliability. He stated that as a nuclear engineer he has a responsibility to the members of the public to ensure the safe, reliable, and affordable operation of DCPP and he takes this responsibility very seriously. Mr. Harbor remarked that PG&E places paramount importance upon the safety of its personnel and therefore it is important that they have the tools, coaching, and standards to ensure they can perform their jobs safely. Mr. MacIntyre observed that the plant completed 18 million man-hours of work without a lost time injury which is within the top decile of performance within the nuclear industry but he stated continued attention needs to be paid to industrial safety and human performance.
Following Mr. MacIntyre’s presentation, Dr. Gene Nelson was recognized. Dr. Nelson commented that he has toured the plant several times and been impressed with the stress placed upon three point contact when ascending or descending a stairway.
Mr. Harbor stated the next information topic would be presented by Dr. Norman Abrahamson, PG&E’s Chief Seismologist with more than 29 years’ experience who holds a Ph.D. in seismology from U.C. Berkeley and who also serves as adjunct professor at U.C. Berkeley and U.C. Davis. Dr. Abrahamson stated he would be assisted in the introductory portion of the presentation concerning source characterization by Dr. Stuart Nishenko who served as the technical manager for the field operations portion of the Central Coastal California Seismic Imaging Project (CCCSIP).
Advanced Seismic Safety Studies.
Dr. Nishenko stated he would be reviewing the results of the CCCSIP report which is a project of PG&E conducted in response to the recommendation of the CEC and per the direction of California Assembly Bill 1632 (AB 1632). He reported the purpose behind the CEC’s recommendation was based upon a recognition that in the twenty years since the original Long Term Seismic Project (LTSP) there have been significant improvements in geophysical data acquisition including geophysical instrumentation, geophysical data processing, differential global positioning system navigation, geographic information systems, and in the use of computerized axial tomography (CT) versus x-ray scans. Dr. Nishenko reported the project identified ten specific parameters, with the assistance of the CPUC’s Independent Peer Review Panel (IPRP) which were key to seismic hazard assessment and he provided a comparison of the range of values, using a tornado diagram, which showed the ratio of hazard values at a fixed point for these significant parameters based upon data collected in 2014 compared to that from 2011 when the report on the Shoreline Fault was completed. Dr. Nishenko stated the diagram shows that the CCCSIP has been able to significantly reduce the range in values. In response to Dr. Peterson’s question, Dr. Nishenko stated that in order to do a seismic hazard assessment you must know something about the frequency of occurrence of earthquakes and the geometry of the faults on which they are occurring as these have implications on how close the fault plane is to DCPP and he commented, as an example, the 2014 data collection was able to constrain the dip values and the geometry of the Los Osos Fault which now is thought to be much steeper dipping than was believed in 2011. He described this as a narrowing of the uncertainty of the selected parameters. Dr. Peterson remarked and Dr. Nishenko agreed that the original estimates had conservatisms which have now been reduced. Dr. Budnitz commented the concept of conservatism does not apply in this context as the process involves making a best estimate to capture uncertainties to provide more confidence in the ultimate hazard assessment for the site and the point is to better understand the data in order to use it in the hazard calculation. Dr. Nishenko remarked regarding the issue of linkage between the Shoreline and the Hosgri Faults it is highly unlikely that a rupture would propagate from one fault to the other but that possibility cannot be excluded and so for purposes of conservatism that consequence was examined. Dr. Lam remarked and Dr. Nishenko agreed that uncertainty analyses generate probability distributions and the uncertainties are generally dealt with by introducing a conservative bias, so as more and better data is acquired a convergency toward a lesser hazard is observed. In response to Dr. Peterson’s comment, Dr. Nishenko pointed out that the data on specific parameters was presented as ratios without a mean value and he agreed with Dr. Peterson’s observation that the main improvement indicated by the data was a better understanding of the geometry of the faults as well as their respective slip rates.
Dr. Nishenko displayed photos showing how the low energy seismic survey work was conducted offshore including the use of multi beam echo sounding for high resolution mapping of the sea floor and low energy seismic reflection which uses sound waves to produce echoes as they reverberate off the sea floor and a photo of the vessel used to conduct these surveys which tows a P-cable array of 14 hydrophone streamers each 50 meters long. Dr. Nishenko reported that the CCCSIP study was one of the first studies to use this technology outside of the oil and gas industry. The survey creates bins of data with dimensions of 2 meters vertically and approximately 3 meters horizontally, which define the minimum spatial resolution of the independent geological features on the sea floor.
Dr. Nishenko displayed photos which show the capabilities of the technology available in the 1980's including those used for the LTSP and compared the results to the data acquired in 2009/2010 using multi beam echo sounder imagery which now shows the Shoreline Fault existing 600 meters offshore from DCPP and provides much greater clarity and resolution than was available with the 2009/2010 data. He reviewed the survey activities conducted for the CCCSIP during 2009/2011, pre AB 1632, and those continuing in 2012. The 2009/2011 work included multi beach echo sounding and potential field mapping for the LTSP, 2-D/3-D low energy seismic surveys (LESS) of the Shoreline Fault zone, and 2-D/3-D onshore seismic reflection surveys in the Irish Hills and Los Osos Valley. The 2012 work included 3-D LESS on the southern Shoreline Fault zone, 3-D High Energy Seismic Survey (HESS) on the Hosgri Fault zone to Point Sal, 3-D HESS on the Hosgri Fault zone to Estero Bay, and 2-D/3-D onshore seismic investigations of the western Irish Hills and DCPP. In response to Dr. Peterson’s inquiry Dr. Nishenko stated the Shoreline Fault was discovered as a result of micro seismic activity aligning along the fault’s trace, the coincidence of the epicenters, and a number of marine magnetic anomalies in its central section. Dr. Nishenko stated part of the initial investigation was to obtain a better understanding of the Shoreline Fault’s geometry and length and the location of its intersection with the Hosgri Fault, the nature of that intersection, and how far it extends into San Luis Obispo Bay. The 2012 work focused on specific sites where estimates could be obtained on fault slip rates and had the advantage of more experience using LESS techniques with a primary objective to understand how fast the Shoreline and Hosgri Faults are slipping.
Dr. Nishenko displayed a schematic diagram showing the product of the digital data on a survey block area of San Luis Obispo Bay and that of a 3-D perspective view of a smoothed similarity bedrock surface of San Luis Obispo Bay, which strips off 15 meters of sea water and 25-30 meters of sediment to allow the cretaceous sandstone structural features at depth to be examined. He described the technology as analogous to a person having a CT scan as opposed to an x-ray as it shows different angles and orientations that were not possible previously with vertical seismic profiling such as was used in the 1980's. Dr. Nishenko reported the photo indicated that a valley had been created and eroded numerous times associated with past glaciation, most recently 20,000 years ago, and the offset of the faults, which have occurred in the last hundreds of thousands of years, can be spotted more easily on the valley walls where they cross geomorphic features. Dr. Nishenko remarked that the spacing between survey lines in the past was approximately 800 meters and now that has been reduced by the use of high resolution data collection and post processing techniques to 12 -15 meters and therefore more subtle features on the sea floor topography are revealed including sharp lineations associated with the Shoreline Fault and Oceano Fault zones. In response to Dr. Peterson’s query Dr. Nishenko confirmed these data sets consist of terabytes. He pointed out the location of the Shoreline Fault, the Oceano Fault and the Los Berros Faults which converge toward the northwest in the vicinity of a navigational hazard known as Souza Rock. Dr. Nishenko stated the motion of the Shoreline Fault zone is shown to be in the order of hundredths of a millimeter a year with the rate of horizontal motion to vertical motion being 10 to 1. The Oceano Fault, predominately a vertical high angle reverse fault, has a rate of amount 0.1 millimeter per year and, together with the Los Berros Fault, shows little evidence for horizontal motion. In response to Dr. Budnitz inquiry on the difficulty of determining the vertical motion of the mostly horizontal Shoreline Fault, Dr. Nishenko stated that this determination is dependent upon its age because the 3 meter cube data envelope can only resolve features that have offsets greater than 3-6 meters so the strata do not show a cumulative offset accumulated beyond 3-6 meters but Dr. Nishenko stated with some of the horizontal horizons evidence is seen for vertical offset of older horizons which are a few hundred thousand years old.
Dr. Nishenko described a slide showing the paleoshoreline dating to 155,000—185,000 years ago in the vicinity of the Shoreline Fault which he reported shows approximately 10 meters of right lateral offset, giving a rate of 0.06 millimeters per year over the last 100,000 years and he stated in response to Dr. Budnitz’ comment that the major uncertainty is the age of the feature which is based upon relative stratigraphy and not an absolute age date and could be off by 35,000—50,000 years. Dr. Nishenko stated a similar analysis was done for the Hosgri Fault where a number of submarine channels were identified, likely related to drainage of the Santa Maria River, and the data shows the offset of the Hosgri Fault over the last approximately 342,000 years with an estimate of the rate of offset on the order of 600—650 meters which gives a slip rate of 1.8 -1.9 millimeters per year which he described as consistent with estimates of slip rates determined farther to the north. In response to Dr. Peterson’s comment, Dr. Nishenko displayed a graphic showing data for the Hosgri Fault slip rate which appears to be approximately ten times larger than the slip rate for the Shoreline Fault and Dr. Nishenko reported relatively the Hosgri Fault remains the primary source. Dr. Peterson observed that, by way of comparison and context, there are structures on the Hayward Fault in the San Francisco Bay area that have been offset by 10 inches in the last 70—80 years. In response to Dr. Lam’s inquiry, Dr. Nishenko stated the interpretation of the data on the slip rates for the Hosgri and Shoreline Faults would be addressed by the Senior Seismic Hazard Analysis Committee (SSHAC) study which PG&E is in the process of completing in response to the NRC’s 10 CFR 50.54(f) letter and the SSHAC study takes a probabilistic approach to seismic hazards as opposed to the CCCSIP report which employs a deterministic analysis.
Dr. Nishenko reported that in response to the CEC recommendation and AB 1632, PG&E determined to employ both high energy and low energy 3-D seismic surveys and made the decision to do the low energy surveys first because permits were received from the State Lands Commission, while PG&E continued to explore the possibility of doing the high energy surveys using air guns. A geophysical permit was subsequently granted from the State Lands Commission but the California Coastal Commission denied the permit on the grounds of environmental concerns. Dr. Nishenko stated PG&E remained interested in the questions to be addressed by the high energy surveys and in the geometry of the Hosgri Fault, as during the LTSP there was controversy about whether the Hosgri Fault was a vertical strike-slip fault or a low-angle thrust fault dipping to the east or possible a listric fault. In response to Dr. Lam’s query Dr. Nishenko stated this controversy was driven by two groups, one of which believed the major faults on California’s borderland were low-angle listric faults while the other group believed the faults in the Santa Maria Basin were high-angle strike-slip faults. He remarked that the data now available from seismic monitoring in the area includes studies on gravity, magnetics, and observations from more earthquake activity and he stated the controversy, in his opinion, has now been resolved in the CCCSIP report.
Dr. Nishenko displayed a graphic showing the comparison with the depth of penetration into the earth’s crust using different techniques including low energy seismic surveys penetrating 200—300 meters, air guns using high energy survey techniques which penetrate 5—6 kilometers with clear imagery but remain above the seismogenic zone, which for earthquakes occurring along the Hosgri Fault is typically at depths greater than 3—4 kilometers, down to 15-16 kilometers. He reported the combination of potential field data and seismicity is consistent with the Hosgri Fault being a high-angle vertical fault and strong evidence is not present for a reverse fault or a listric fault as previously hypothesized. Dr. Budnitz observed that the data appears to indicate there is a much lower probability of shallow reverse fault characteristics and Dr. Nishenko confirmed that the data in the report shows that if the dip of the Hosgri Fault is changed the variation on the magnetic field values constrain the dip, indicating it is characterized as vertical rather than shallow. In response to Dr. Lam’s question, Dr. Nishenko confirmed that with a record including 40 years of seismic activity and with advances in the ability to more accurately locate earthquakes, review patterns of magnetic and gravitational anomalies, and better assumptions concerning composition of the rock, which led in part to the identification of the Shoreline Fault, there is an increased level of confidence in the interpretation of the Hosgri Fault as a vertical fault.
Dr. Nishenko displayed a photograph of the vibrocise vehicles, each weighing 65,000 pounds, used to conduct high energy seismic reflection profiling surveys in the Irish Hills during 2011 and 2012. The purpose of this effort was to integrate surface geologic mapping with shallow high resolution seismic profiling down to 5—8 kilometers. He displayed a map of the Irish Hills where survey activities occurred on 110 miles of access roads over very steep topography with limited access which made the feasibility of doing true 3-D profiling somewhat limited. He displayed a ‘fence diagram’ summarizing the major elements of the interpretation of the geology and geologic structure of the Irish Hills which he stated is an asymmetric basin formed about 22,000,000 years ago in a transtensional regime with active spreading and opening of the basin about 3,000,000—4,000,000 years ago coincident with plate motion in the Gulf of California which altered its features from transtensional to transpressional and then the basin closed again. Dr. Nishenko stated the Edna Fault near the center of the Irish Hills is a steep fault, on the order of 60—80 degrees dip, and it appears to be the major structural boundary of the basin to the northeastern side and there are a number of blind faults associated with the Edna Fault. The Los Osos Fault to the east is also a steep fault with a dip of 55—80 degrees and is characterized by a mostly reverse or reverse oblique motion but it does not appear to be as well developed as previously believed and as you approach Morro Bay, the Edna Fault dives and becomes a blind fault or a fault propagation fold rather than an actual fault surface. To the west is the Shoreline Fault which has been demonstrated to be a steep vertical fault and the San Luis Bay Fault which cuts across DCPP’s Avila Beach gate and obliquely across the Irish Hills and joins with the Shoreline Fault further to the north. Dr. Nishenko stated that while the fence diagram only shows the top few kilometers it is believed that all the faults he mentioned converge or coalesce at depth into a single root zone associated with the Edna Fault zone and he confirmed, in response to Dr. Budnitz’ remark, that this is consistent with the change from transtensional to transpressional occurring 3,000,000—4,000,000 years ago.
Dr. Nishenko stated that the formations are Franciscan and are very broken up. He displayed graphics which compared geologic cross sections with the proponent model which PG&E is addressing as part of the IPRP and AB 1632 process. He compared the cross sectional view proposed by Dr. Douglas Hamilton on which Dr. Hamilton based his prediction about the geometry of certain faults. Dr. Nishenko stated Dr. Hamilton’s proposal inferred the offshore thrust of the Los Osos Fault as the essential feature of geology to explain the uplift of the Irish Hills. Dr. Nishenko stated the CCCSIP data collection and seismic imaging process now demonstrates that the Los Osos Fault dip is steeper than the 45 degree dip originally proposed. With reference to the San Luis Bay Fault zone, the projected zone where Dr. Hamilton inferred offshore thrust is proposed to exist shows no evidence of cross cutting the vertical fault zone and the data shows no evidence for vertical faults being offset by sub horizontal faulting and Dr. Nishenko stated the geology in that area is best represented by a steeply dipping San Luis Bay Fault. However, Dr. Nishenko stated the Irish Hills are uplifting but other models may need to be considered to explain this including the role of the Los Osos Fault and the southwest boundary zone, with a series of reverse faults dipping toward one another to produce the uplift and also perhaps other offshore faults such as the Hosgri Fault.
Dr. Nishenko reported the CCCSIP report also addressed concerns with the Diablo Cove Fault which was uncovered during excavation for DCPP during the 1960's and he displayed a photo of the mouth of Diablo Creek taken in 1972 during the construction of DCPP. He stated there is no dispute that the fault is present and that it goes underneath the corner of the Turbine Building. He displayed a graphic showing the attitude of the fault with reference to excavations done during initial construction of DCPP and two pictures of the fault. He stated there is not a lot of displacement across this feature and when it was mapped in the 1960's it was observed that there is a quaternary alluvial terrace deposit atop the bedrock surface that dates to 125,000 years ago and the fault does not disrupt that deposit indicting its lack of activity during that period. The fault appears to be discontinuous with directional surface traces which do not follow the same trend and no evidence is present for significant or any offset at depth based upon high resolution seismic profiling and no convincing evidence of an offshore connection. Dr. Nishenko described this as a secondary faulting feature more akin to a bending moment fault associated with the bending and folding of rock rather than a through-growing seismic feature. Dr. Nishenko stated that all lines of evidence have led PG&E to disregard the Diablo Cove Fault as a seismic threat to the plant.
Dr., Nishenko reported the third element of the seismic imaging project involved the installation of an array of ocean bottom seismometers (OBS), comprised of a three component accelerometer and a three component broadband seismometer, offshore from Point Buchon to monitor in detail the area of the intersection of the Hosgri and Shoreline Faults and he displayed a map of the installation area and a photo of the 1-ton concrete cap containing the OBS which protects the device from trawling activities on the sea floor. The OBS devices are connected by cable to provide real time monitoring capability when earthquakes occur.
In summarizing his presentation, Dr. Nishenko stated the Hosgri Fault slip rate has been revised from 0.5 to 6 millimeters with a preferred rate of 2.25 millimeters per year to approximately 1.8 to 1.6 millimeters per year and the Shoreline Fault slip rate previously estimated at 0.3 millimeters per year has been revised to 0.01 to 0.06 millimeters per year. The previous assumption in the LTSP of a boundary between the Hosgri Fault and the San Simeon Fault has been relaxed to assume a rupture could propagate and produce a larger magnitude earthquake on the Hosgri Fault. The possibility of a linked rupture of the Hosgri and Shoreline Faults was analyzed and no convincing evidence was found for a joint simultaneous rupture in the past but for purposes of the analysis and investigation of the consequences they were linked together. Finally, the length of the Shoreline Fault was established as 45 kilometers, from its intersection with the Hosgri Fault off Point Buchon to its southern terminus near Guadalupe in Point South, which is almost double its 2011 estimate of 23 kilometers due to extending the Shoreline Fault through San Luis Obispo Bay. As a result, the Shoreline Fault was found to have an increased maximum magnitude length relationship.
Dr. Norman Abrahamson, Chief Seismologist for PG&E Geosciences, continued the presentation. Dr. Abrahamson stated that two approaches exist to doing a seismic hazard analysis. A deterministic approach postulates that an earthquake has occurred and estimates what the range of ground motion might be. A second approach is probabilistic and focuses upon how large is the ground motion produced at a specific site from all possible faults, adds those contributions together, and tracks the rate at which seismic events occur. Dr. Abrahamson remarked the NRC is moving toward the use of probabilistic results for risk assessment and the CCCSIP studies were not prioritized to optimize deterministic results. He stated the sensitivity diagram used by Dr. Nishenko impacts probability. A common currency of seismic moment is developed taking the area of the fault, the amount of its slip (or an abrupt release), and the rigidity of the crust to calculate the energy released by the earthquake. This calibration of magnitude uses data from the seismogenic portion of the rupture not the aseismic slip so that for a fault that is creeping, such as the Hayward Fault, it is not releasing the type of energy which concerns seismologists. Dr. Abrahamson reported energy is determined using the area of the fault and its rigidity but the slip rate is used and he described the area of the fault and the slip rate as key parameters, as doubling the slip rate and if the other factors stay the same, the rate of earthquakes is doubled. Events of lesser magnitude, slower slip rates with less area are not screened out of the data but are included in the sum of the data. In response to Dr. Budnitz’ question concerning how a paleo event which occurred long ago can be differentiated, Dr. Abrahamson replied that if no evidence of creep exists but active creep is ongoing it is assumed it is all seismogenic and an episodic release is presumed. He remarked that very few faults creep and the San Francisco Bay area is unusual in that a number of such faults exist there.
Dr. Abrahamson reported that initially in the study of the Shoreline Fault there was no direct evidence of its slip rate. Gravity and magnetic data were consistent with a vertical strike-slip fault and the only manner to assess the slip rate was to review its gross geomorphology compared to other faults. Its slip was accordingly estimated at between 0—1.0 millimeter per year. With data now available on the Shoreline Fault deformations an actual measurement of the slip rate is possible. In 2011, with an assumption of 1/3 millimeter per year, the Shoreline Fault was believed to contribute 20% to the seismic hazard at a 10-4. With the new slip rate calculation using CCCSIP data the Shoreline Fault is now believed to contribute 4% to the seismic hazard at the same level. Dr. Abrahamson stated that at that level it is not worthwhile to engage in an effort to refine the slip rate calculation by taking core samples. The Shoreline Fault is now seen as a much smaller contributor to the probabilistic hazard. A different case is established under a deterministic approach, as the deterministic approach does not include how often an event might happen. Dr. Abrahamson stated the seismic hazard approach is to be mean-centered and to capture the scientific uncertainty and there is no intent to be conservative. The energy from an earthquake may be released in many small events or in one large event or in an even larger earthquake which will happen less often. He stated the probabilistic risk type of analysis is somewhat counter intuitive in that larger earthquakes and a linkup of faults produces a lower hazard because such earthquakes happen less often. For the deterministic approach, when faults are linked a larger earthquake is produced with a larger ground motion. So what is conservative for deterministic is unconservative for probabilistic. Dr. Abrahamson described the CCCSIP efforts as therefore being directed to using the best science to track and reduce uncertainty by collecting data to begin to limit ranges of the models that are not inconsistent with observations. Dr. Budnitz observed, and Dr. Abrahamson agreed, the logic of the probabilistic approach to seismic hazard assessment enables disparate faults and sources to be pulled together in a way that produces a coherent measure of the hazards at the site. Dr. Peterson observed that an understanding is required of the energy imparted at different frequencies during an earthquake and Dr. Abrahamson agreed and confirmed that strong ground motion can be produced from moderate as well as large earthquakes. Dr. Abrahamson remarked the analysis presented to the DCISC was simplified to use 5 hertz as the frequency but the broad range of frequencies are covered in the CCCSIP study. In response to Dr. Peterson’s question on predicting the frequency at which energy will be delivered by a seismic event Dr. Abrahamson replied that determination is empirically derived from earthquake recordings taken around the world with a large standard deviation employed as part of the probability calculation and seismic hazard calculation includes a combination of the chance that an earthquake will occur, the probability of the event, and the site’s location relative to the distribution of the ground motion. Dr. Abrahamson remarked that DCPP is more likely to get strong shaking from a very unusually energetic moderate-sized earthquake, magnitude 6—6 ½, than it is from a larger event. Dr. Peterson observed Dr. Abrahamson statement illustrated the argument for probabilistic analysis as it looks at what gives the greatest risk from the events which happen with the most frequency and Dr. Abrahamson agreed and added the probabilistic approach recognizes that strong shaking can be produced by a range of earthquakes with varying magnitudes but if lesser magnitude events are more frequent then there is a higher chance that one of them will produce excessively strong ground motion.
Dr. Abrahamson observed earthquake scenarios involve magnitude, geometry, and location. He stated geometry is an important parameter for DCPP due to the ‘hanging wall effect’ whereby the hanging wall of a thrust fault can produce up to twice the ground motion and high frequency content as produced on the other side of the fault. Global ground motion models are constructed using data from earthquakes around the world and use distance, reference to the rock site conditions, and the frequencies observed and the strength of shaking for an average rock site. The results are then applied to assess DCPP’s site response with data on site-specific rock and soil property and recordings at DCPP from past earthquakes. This permits a spectrum to be created whereby the worldwide models are calibrated to the site conditions at DCPP to provide an accurate representation of what the shaking will be under different earthquakes. In response to Dr. Lam’s query, Dr. Abrahamson replied the latest data set has approximately 20,000 earthquake recordings, including almost 1,000 recordings within 20 kilometers for magnitude 6 and above events, which he described as greatly improved from the amount of data available when the initial work was begun in the 1970's and later. In response to Dr. Peterson’s observation, Dr. Abrahamson stated the directivity effect, the increase in strength as the energy propagates, is addressed as a contribution to the distribution in the models and is included in the calculation of the broad standard deviation although broad uncertainties still exist.
Dr. Abrahamson displayed a graphic of the geophysical survey activity in the vicinity of DCPP including the locations where the vibrocise trucks operated and the location of the thousands of seismometers used to take readings and he stated that these seismic exploration efforts have produced data that no one has ever had access to in terms of attempting to characterize the site conditions. He remarked these surveys propagated underneath the power plant and with that data tomography can be done and inverted to determine velocity. He displayed a 3-D site velocity model for DCPP with high velocities of 1,500—1,800 meters per second through very hard rock indicated in red, lower velocities of 1,000 meters per second in green, and even lower velocities of 600 meters per second in blue. He described the area of DCPP as having complicated geometry, as the area was in a previous subduction zone from which the accretionary wedge is scraped off, but he stated that the deeper readings become more consistent. Dr. Abrahamson remarked this type of image has never before been available and previous data was acquired by boring into the subsurface. Dr. Abrahamson stated PG&E now has a better understanding of the variability of the geologic structures below the power plant and this is important as higher velocities typically lead to lower ground motion.
Dr. Abrahamson provided a graph of the average of the shear wave velocity profiles for the DCPP Power Block and the Turbine Building foundations, as determined by data previously acquired and data acquired as part of the CCCSIP surveys. He observed the Turbine Building is a lower velocity structure, with more amplification when compared to the Power Block and this would result in larger ground motions going to the Turbine Building for the same earthquake than for the Power Block. In response to Dr. Peterson’s question Dr. Abrahamson confirmed the Turbine Building and the Power Block are not coupled together in such a fashion that they would move together during an earthquake.
Dr. Abrahamson stated the traditional DCPP site response evaluation uses the recorded ground motions at the DCPP free-field site, particularly from the San Simeon and Parkfield earthquakes, to adjust the global average models to DCPP site-specific characteristics. He stated a key finding, as the global data sets have increased, is that the global average is not correct. Wave propagation through the crust is a systematic, repeatable, behavior. Dr. Abrahamson stated that ten earthquakes in the same area going to the site are going to pass through the same crust and each site has its own personality and with the new empirical data from the CCCSIP it is now possible to observe this deviation from the global average and measure the elastic properties of DCPP buildings and calibrate the model for DCPP’s shallow and deeper soils. Drs. Peterson and Budnitz observed this is important for a fragility assessment and provides a firmer basis for infrastructure response spectra. Dr. Abrahamson stated that before those spectra can be established it is necessary to account for attenuation by distance using recordings at other sites to remove the average affective source and the propagation by distance from those earthquakes. This records the event as a function of distance but does not use DCPP-specific data to compare to the global model. After correcting for the path and the source, site-specific data indicates that there is a site resonance in the range of 2—3 hertz and the DCPP site has stronger amplification at low frequencies and weaker amplification in the range greater than 5 hertz as compared to an average rock site in California.
Dr. Abrahamson displayed a graph of the DCPP site-specific terms from the San Simeon (in blue) and Parkfield (in red) earthquakes showing the site-specific high and low ranges and the global average high and low ranges. He confirmed Dr. Peterson’s observation that the data shows a higher content in the lower frequency ranges and less in the higher frequency ranges where mechanical equipment might be expected to be more fragile. Dr. Abrahamson stated the data shows a lower content than the global average would indicate. He stated PG&E is now developing new and better fragility models based upon the data from this site-specific spectrum. More data, even from very small earthquakes, will be evaluated from the densely recorded areas around DCPP which will give an even better evaluation.
Dr. Abrahamson reported the data collected for the source characterization will be used in the SSHAC study and a deterministic evaluation is being done to evaluate whether a problem exists using bigger magnitudes including assuming a longer Shoreline Fault and a linked event on the Hosgri and Shoreline Faults to assume a larger earthquake. Dr. Abrahamson remarked DCPP is not very sensitive to the magnitude of the earthquake when assessing high frequency shaking levels. He displayed a map of the Hosgri and Shoreline Faults and confirmed Dr. Peterson’s comment that high frequency shaking comes from within an approximate distance of 25 kilometers and the main structural models are in the 3—8 hertz range with fragilities being key to the parameter he discussed. Dr. Abrahamson reviewed a graph of the latest ground models, developed last year, and noted that at magnitude up to 5—8 from magnitude 5—6 ½ the ground motion goes up by a factor of 2, but once the 25 kilometer range is reached, around magnitude 6.2, the curves begin to flatten for both the Hosgri and Shoreline Faults and there is very little increase in the high frequency ground motion close to the fault as more and more total energy is added to the earthquake as it spreads out over a large diameter. As the data goes from magnitude 6 ½—6.7 or 7 the ground motion is changed by less than 10%. Dr. Peterson observed this data indicates that stronger earthquakes or earthquakes involving a longer length fault will generate stronger ground motion at low frequencies. Dr. Abrahamson reported the lowest frequency considered by the current approaches is ½ hertz. Dr. Abrahamson reported the plant’s cranes are sensitive to ground motion and sloshing of the spent fuel pools will occur and did occur during the San Simeon earthquake and new models include data to 0.1 hertz as the NRC has requested that studies go at least to 0.5 hertz. Dr. Peterson remarked that at Fukushima there was considerable uncertainty about the spent fuel pool water levels as the ground motion at low frequencies from the Great Japan earthquake occurred for a protracted period of time during which water was observed sloshing over the spent fuel pool handrails.
Dr. Abrahamson reported the scientific data in California shows the faults can produce large earthquakes and therefore allowance must be made for rare occurrences of earthquake faults rupturing simultaneously and creating larger earthquakes. Dr. Peterson observed this supports the fact that the most important vulnerabilities will tend to come from a combination of factors associated with smaller earthquakes and to focus on extremely large earthquakes misses this point.
Dr. Abrahamson displayed a graph showing deterministic sensitivity of the Power Block and the Turbine Building under the various design spectra including work done in 1977, in 1991 as part of the LTSP, and the CCCSIP studies using local data. The spectrum now peaks at 2 ½ hertz, and is still bounded by evaluations done from the 1977 spectrum and the conclusion is that there is no immediate safety issue and PG&E will proceed with the SSHAC study to complete the full evaluation to build the full probabilistic analysis. He displayed a graph of the sensitivity when the Shoreline and Hosgri Faults are modeled as linked and rupture together. Dr. Abrahamson stated the geometry is such that as the rupture goes from one fault to the other it is releasing bend, which is basically an energy sink, and so the rupture stops. From all the dynamic rupture models conducted it was not possible to get more than 2 kilometers onto the next fault. Dr. Abrahamson remarked that if the Shoreline Fault had been located on the other side of the Hosgri Fault the conditions would have been more favorable for a longer rupture. He reported that postulating a 7.3 magnitude event on the Shoreline Fault and linking it to the Hosgri and San Simeon Faults creates a larger earthquake but with the magnitude at short distance it doesn’t move the ground motion model as much and therefore the plant is not especially sensitive to the magnitude of a seismic event and Dr. Abrahamson stated the biggest issue for PG&E is the angle and dip of the faults as those are the factors which have the most impact in terms of the near fault ground motion. Dr. Peterson observed and Dr. Abrahamson agreed that in the 5 hertz range, where many of the fragilities exist, the actual peak acceleration and duration shown on the graph would be significantly lower than the plant’s design basis. Dr. Abrahamson confirmed that most of the equipment fragilities are not driven by fatigue and with the distances involved the strongest part of the shaking at large amplitudes lasts for approximately ten seconds even as the magnitude of the earthquake increases. Dr. Peterson confirmed his understanding that with the lower frequency coming from a longer distance the duration shaking at higher frequencies will not last long and the lower frequency will be of longer duration.
In summarizing his presentation, Dr. Abrahamson stated the new seismic source information shows the potential for larger magnitude events on the Hosgri and Shoreline Faults and the slip-rates for the Hosgri and Shoreline Faults are somewhat smaller than previous estimates which only affects the probabilistic results. There is now much more detailed site velocity information available specific to DCPP which Dr. Abrahamson described as unprecedented and unavailable in any other place in the United States. He stated the implications for DCPP include a showing that the updated ground motions are bounded by the results of the 1977 ground motion spectrum and the plant has more margin than previously estimated. Dr. Peterson observed that while this was valuable information, DCPP needs to also confirm that plant personnel are going to remain safe during an earthquake. Dr. Abrahamson confirmed Dr. Budnitz’ observation that the studies Dr. Abrahamson discussed are feedstock for the SSHAC analysis which will then complete the probabilistic integration and later, after that integration, there is also a differentiation process as a part of the probabilistic SSHAC process and Dr. Abrahamson confirmed this work will be completed within the next six months. The full, updated hazard analysis is due to be completed by March 2015, and Dr. Abrahamson confirmed the three ground motion characterization workshops held recently were conducted using this data. In response to Dr. Lam’s request, Dr. Abrahamson stated there is a potential, not a certainty, for larger magnitude events on a larger area of the faults but the margin for such events comes not from the magnitude of the event but from the ground motion model. He stated it is a two-part process, first to characterize the source which is determinative of the magnitude and the geometry involved and then to use the ground motion model to estimate the shaking from the event. Dr. Abrahamson stated the greatest change from what was done in 1977 and in 1991 is the improved ground motion model and that improved model is responsible for the difference in the spectra, not the source characterization. PG&E now has much larger data sets than previously available and now has local data for use to assist with calibrating and correcting the global model. In response to Mr. Wardell’s inquires, Dr. Abrahamson replied the Loma Prieta earthquake was too far away to be recorded at DCPP due to its distance. Dr. Peterson remarked he is now convinced that large earthquakes can occur on the Hosgri Fault and their frequency at under 1,000 years means that at some point in the future a large event will occur and this needs to be considered in the plant’s seismic design basis. Dr. Abrahamson remarked there is no doubt that the Hosgri Fault is active. Dr. Abrahamson confirmed, in response to Mr. Wardell’s question, that DCPP is near multiple faults and therefore a very robust design basis is required as DCPP has a higher seismic hazard than other nuclear power plants and accordingly it has a much higher seismic design basis. He remarked that an analysis of the level of safety involves not just the hazard but also the capacity of the plant to withstand the hazard. Dr. Abrahamson stated the Diablo Cove Fault is a bedrock fault or fracture that goes only to depths of tens of meters and is incapable of producing a large earthquake. All of California has bedrock faults but he stated the Diablo Cove Fault is not a seismogenic source capable of releasing significant energy.
Dr. Peterson thanked Dr. Abrahamson for his presentation and opened the floor to public comment.
Dr. Gene Nelson was recognized. Dr. Nelson stated he previously discussed the subject of what he termed aperture earthquakes with Dr. Abrahamson and he described this as a core concept which he summarized as the concept that essentially the impact of an earthquake is going to be based upon the proximity of the faults and the earthquakes effects attenuate quickly over relatively short distances.
Mr. David Weisman, representing the A4NR was recognized. Mr. Weisman remarked that during the Committee’s discussion of the Evaluation of alternatives to once-through cooling at DCPP it was agreed that the work was preliminary in nature and he suggested that PG&E’s use of the term “Final” for its recent report on the CCCSIP seismic analysis was a misnomer and that report was really a preliminary draft. Mr. Weisman commented during Dr. Nishenko’s report on the effort to identify the range of hazards by use of the tornado diagram Dr. Nishenko referred to the input of the IPRP but that represented the only discussion of the IPRP which, he remarked, was akin to the manner in which coordination with the IPRP took place. Mr. Weisman stated the IPRP last met on July 11, 2013, and the IPRP raised a number of issues which were discussed in Drs. Nishenko’s and Abrahamson’s presentations including the need for more data and more study. Mr. Weisman stated the IPRP was created by the CPUC to act as an ombudsman for PG&E’s ratepayers and to ensure that PG&E’s report on the seismic conditions at DCPP received a fair and open review. However, he stated PG&E delivered the CCCSIP report to the IPRP on the same day as the story of its release appeared in local newspapers. Mr. Weisman remarked in his discussions with the CPUC he was advised their review would take six to eight months and he observed this puts the schedule for conclusion of that review well past the date of March 2015 by which PG&E must complete the SSHAC study. Mr. Weisman reported the IPRP will meet on October 23 and again of November 17, 2014 and he suggested that the DCISC should attend those meetings. Mr. Weisman stated that as a member of the public and a PG&E ratepayer he would not characterize the CCCSIP studies as being final because the ombudsman assigned to protect the public and the ratepayers’ interests was not consulted. He stated that PG&E has issued statements that the CCCSIP study would be made publicly available but he questioned when and to whom it would be made available. Dr. Budnitz replied that he and Dr. Peterson are planning to attend the scheduled meetings of the IPRP and will monitor the work of the IPRP as the DCISC has done for the SSHAC ground motion workshops. Dr. Budnitz stated it was not important to him what PG&E chose to title its report because until the IPRP has had a chance to review and opine on the work it will not be final. Dr. Lam stated he appreciated Mr. Weisman’s comment and he was comfortable with labeling Drs. Nishenko’s and Abrahamson’s presentations as preliminary.
Dr. Nishenko, in response to Mr. Weisman’s remarks, stated that as part of PG&E’s commitment to transparency all data collected for the CCCSIP project has been made available on two public websites. The marine data is located on the United States Geological Survey (USGS) website with the National Archive of Marine Seismic Data and the land seismic data is presently available on the Incorporated Research Institutions for Seismology (IRIS) website which is a university consortium. Dr. Nishenko reported that various levels of peer review were conducted as part of the CCCSIP studies including review of each individual chapter through an independent technical review process, and the entire CCCSIP report is being compiled under a nuclear quality assurance process. He remarked the DCISC, the NRC, and the IPRP all act as independent reviewers and all comments received will be taken into consideration. Dr. Nishenko stated the CCCSIP report is in the nature of a snapshot in time and PG&E continues to have a long term commitment to monitor and assess seismic safety issues for DCPP as part of the LTSP. Dr. Nishenko confirmed, in response to Dr. Budnitz’ inquiry, that the data sets derived from the CCCSIP will be used by the SSHAC Level 3 group to inform the ultimate results of their analysis. Dr. Budnitz observed that in this process there is always the probability that there will be new information and in that sense the SSHAC results are a snapshot in time. Dr. Abrahamson stated that the best that can be done with the data is to set the ranges and uncertainty bounds such that when future studies are conducted the results are found to be within those bounds. Dr. Budnitz agreed and stated that with reference to the SSHAC guidance, if data is found to move within the center, the body, and the range this creates a level of confidence and the process is a success. Dr. Abrahamson confirmed that PG&E is not taking the position with the CCCSIP studies that the matter is closed and will not be further reviewed, and as new techniques and information are developed they will be incorporated into the hazard analysis. He commented the SSHAC study marks the end of phase one but incremental updates will continue with possibly a major update in ten years. Dr. Lam remarked he found merit in the willingness of the A4NR to also examine the data and the numerous assumptions involved in this approach in order to advance a safety agenda for DCPP.
Ms. Sherry Lewis representing MFP was recognized. Ms. Lewis commented use of the term ‘final’ would likely be confusing to the public and gives an impression that is not accurate. Dr. Budnitz replied the DCISC is without authority to direct PG&E with regard to the title of its study.
Mr. David Weisman representing the A4NR was recognized. Mr. Weisman reported that in the transmittal letter with the CCCSIP study from PG&E’s Chief Nuclear Officer to the NRC it was stated that the underlying data would be made available to academic institutions and stakeholders after the peer review process and this statement is what caused him confusion as it appears to be different than the statements made following the presentation.
Mr. Wardell reported that he has transmitted a revision of the Evaluation of the Bechtel Addendum showing the changes from the version reviewed and discussed earlier in this public meeting to each DCISC Member and to Mr. Linnen, and Mr. Wardell asked that each of them provide comments directly to him this evening for preparation of a second draft to be considered the following day.
XI Adjourn Evening Meeting
Drs. Budnitz and Peterson thanked the PG&E representatives and the members of the public for their attendance. The Chair commented the Committee has scheduled a public tour of DCPP for the following morning at 8:00 A.M. which has been booked by prior reservation, and the public meeting of the Committee will reconvene at 1:00 P.M. tomorrow. Dr. Peterson then adjourned the evening meeting of the Committee at 8:35 P.M.
Public Tour of Diablo Canyon Power Plant
The three members of the DCISC accompanied by 17 members of the public, PG&E tour guide Mr. John Lindsey and the Committee’s consultants, conducted a tour of certain accessible areas of the Diablo Canyon Power Plant (DCPP). The members of the public responded to the DCISC advertisement concerning the public tour placed in a local area newspaper and on the DCISC’s website. The group met at the PG&E Energy Education Center for an introduction to the Committee members and consultants and a short presentation on the background and role of the Committee. Mr. Lindsey provided a brief overview of DCPP including its history, operation, the nuclear fuel cycle, spent fuel storage and plant security. PG&E discussed how the plant’s cooling systems work, with the ocean water two physical barriers away from the reactors. The group was issued visitor badges and then departed for DCPP.
After entering the plant through the Avila gate, the members of the public were then divided into two groups, each accompanied by at least one DCISC member and consultant, and each group visited in turn the Control Room Simulator Facility and the lobby of the Security Building for a demonstration of screening of personnel entering the protected areas of the plant and viewed the ocean water Intake and Outfall Facilities where DCPP pulls in and expels seawater used for cooling. The bus then drove by the site of the Independent Spent Fuel Storage Installation (ISFSI) for a description of its purpose and features and then stopped at the plant overlook site and the group received a briefing from PG&E representatives on the various external features and buildings.
Questions & Comments From the Public
During the ride back to the Energy Education Center the group received information on radiation protection and members of the public took the opportunity to ask questions of Committee members and consultants.
Conclude Public Tour
XXI Reconvene For Afternoon Meeting
The October 15, 2014, afternoon public meeting of the Diablo Canyon Independent Safety Committee was called to order by its Chair, Dr. Per Peterson, at 1:05 P.M.
XXII Committee Member Comments
Dr. Budnitz reported the discussion during the previous evening session on seismic issues was of great interest and contained a substantial amount of technical information which will take some time to fully assess.
XXIII Public Comments and Communication
The Chair invited any comments from members of the public.
Mr. David Weisman representing the A4NR was recognized. Mr. Weisman stated he would provide to Dr. Lam a legal brief on behalf of the A4NR dealing with cost recovery for PG&E’s seismic studies. Dr. Budnitz remarked this brief had already been provided to the DCISC. Mr. Weisman stated he based his earlier comments regarding PG&E’s treatment of the IPRP process as part of the final seismic review on the brief. Mr. Weisman remarked that from discovery and document requests made by the A4NR documents were identified from PG&E which address different levels of mitigation strategies proposed by PG&E to deal with contingencies posed by the IPRP’s review including to address a situation where the IPRP might propose additional data processing or interpretation in its review of the CCCSIP project’s results which are to be provided to the IPRP as a condition of CPUC funding for the CCCSIP project. Mr. Weisman stated documents received include information on PG&E’s assessment of risks from the IPRP process including concern about the impact to scope and schedule which he stated were rated as a high level of concern by PG&E. Mr. Weisman reported PG&E has considered stressing with the IPRP that advanced processing and methods of interpretation techniques recommended by academia and the industry were used in the CCCSIP study and that the process and data will be made available to the IPRP before the technical reports are to be provided for IPRP review. Mr. Weisman stated PG&E has identified the charter of the IPRP to be the review of results and PG&E may be planning to potentially challenge any recommendation by the IPRP for additional processing or interpretation as being outside the scope of the IPRP’s mandate. Mr. Weisman remarked that the California Coastal Commission did not completely reject PG&E’s application for a permit to conduct the high energy offshore studies but rather the Coastal Commission stated the permit submitted by PG&E did not meet the needs of the Coastal Commission. Mr. Weisman cited information from an email provided to the A4NR concerning the high energy studies and Mr. Weisman observed PG&E never went back with a revised application for a Coastal Commission permit. Mr. Weisman also cited information from internal emails from PG&E’s Legal Affairs Department, redacted in part by PG&E, and from PG&E’s Director of State Agency Relations, to PG&E staff which Mr. Weisman stated were obtained by the A4NR pursuant to a discovery request concerning the IPRP Report No. 6 and PG&E’s communication with CPUC staff regarding the IPRP and Mr. Weisman observed that after IPRP Report No. 6 all public meetings ceased. Mr. Weisman commented he remains skeptical concerning PG&E’s commitment to further review. Mr. Weisman stated there were emails produced in response to A4NR’s discovery request which he was not allowed to review as only the A4NR’s attorney executed the required nondisclosure agreement. Dr. Lam stated that Mr. Weisman provided him with a copy of the A4NR Opening Brief dated February 28, 2014, and he confirmed the DCISC previously received a copy of the document. Dr. Lam stated without reference to the merits of counsel’s arguments in the Brief, the Brief contributes to a useful public debate.
Ms. Jane Swanson, representing MFP, was recognized. Ms. Swanson requested confirmation that the DCISC was not a member of the inter-agency review committee (the RCNFPP). Dr. Peterson stated that Ms. Swanson’s statement was correct. Ms. Swanson stated that the Evaluation claims during the August 13, 2013 meeting of the RCNFPP that the DCISC was asked to provide its recommendations. She observed the notes of that meeting contain references only to the DCISC representatives making comments to Bechtel. Ms. Swanson stated her belief that the DCISC is attempting to give the impression that it has a more formal role in the SWRCB process than it actually has and therefore the comments of the DCISC to the SWRCB are entitled to the same weight as those provided by any individual citizen. Dr. Peterson replied that as a state-chartered committee, reporting to senior state government officials, the DCISC was not acting as members of the public in performing its review. Dr. Peterson remarked that review of operational safety at DCPP is something the DCISC is obligated to conduct under its charter from the CPUC. Dr. Peterson stated it was his expectation that there is a corresponding obligation on the part of other state bodies to formally involve the DCISC in matters concerning its charter. Ms. Swanson commented that it was her belief that the DCISC was not requested to provide its Evaluation by the SWRCB/RCNFPP but instead the DCISC decided on its own initiative to do so. Dr. Budnitz remarked that this was not an accurate statement concerning the Evaluation of the Bechtel Assessment which was approved by the DCISC on September 4, 2013. Dr. Budnitz confirmed that at a previous meeting of the RCNFPP the DCISC expressed interest in conducting a review of the Bechtel Assessment and was asked to do so by the RCNFPP. Dr. Lam stated that it was his recollection the DCISC identified the obligation to conduct the review prior to being requested to do so by the RCNFPP. Dr. Peterson remarked he was surprised initially that the meetings of the RCNFPP were not well publicized and attending the meetings in person was a way to remain cognizant of matters that could potentially represent major changes to DCPP and its operation. Ms. Swanson thanked the Members for their responses and stated she intended to state that the DCISC’s Evaluation was not entitled to a standing different from that of the public. Ms. Swanson stated the draft Evaluation of the Bechtel Addendum draws unsubstantiated conclusion and, in her opinion, appears to be biased. She stated her belief that the DCISC should commence its review again from the beginning because the Evaluation gives the appearance of an attempt by the DCISC to lobby on behalf of PG&E’s effort to gain an exemption from the state’s Marina Protection Policy.
Dr. Peterson stated the FOE comments and critique of the Bechtel Addendum were focused on the ways in which cooling towers might be designed to reduce their cost. Dr. Peterson stated the Evaluation agrees that some of the changes proposed would be unlikely to have a substantive impact on plant safety. He remarked, however that a proposed six-year construction period on the south side of the plant with both units remaining in operation would have a substantive effect on operation of the plant as would the use of saltwater in the cooling towers with the associated potential to greatly increase the quantities of salt which would be deposited on the plant. Dr. Peterson remarked that after the attacks on September 11, 2001, modifications were made to the plant to enhance security and these modifications were very carefully reviewed for their impact on safety particularly in the area of emergency response and plant operations. Dr. Peterson stated his belief that a large scale construction project located to the south of the plant site would certainly require very careful review and would generate some negative impact on plant operation and the question which must be answered is the magnitude of that impact and whether it is acceptable as compared to the alternative of siting cooling towers to the north of the plant. Dr. Peterson stated he doubted that a conclusion could be reached that the DCISC has some ulterior motive in its concerns on these two particular issues as the Evaluation discussed several other design changes which could make the proposed design changes more affordable and which would likely not have a substantive effect on plant safety. Dr. Peterson stated that in its Evaluation the DCISC must use its best judgment and the DCISC has committed to further study of the specific questions in greater detail in order to establish a better factual basis for its understanding.
Mr. Rathie distributed copies of the revised draft of the Evaluation of the Bechtel Addendum in a final version and in a version showing changes from the version provided with the public agenda packet for this meeting.
Dr. Lam proposed that a disclaimer be added to the Evaluation that the DCISC has no intention to assist any parties’ effort or to contribute to any conclusion that would be counter- productive to compliance with the federal Clean Water Act. Dr. Budnitz strongly objected to adding the disclaimer proposed by Dr. Lam as the DCISC’s Charter provides for its independent role. Dr. Peterson then called for public comment on the latest draft.
Dr. Gene Nelson was recognized. Dr. Nelson stated he emailed a formal statement regarding his position in opposition to the proposal to install cooling towers at DCPP. He observed the SWRCB would force PG&E to place a large volume of highly conductive saltwater and brackish water with a high flow velocity above the 85 foot level at the plant. He stated his opinion this is a disaster waiting to happen and an earthquake would not be required to unleash what he described as a man-made saltwater tsunami at DCPP and thereby seriously compromise long term plant safety. He recommended that the DCISC oppose the proposal by the SWRCB. Dr. Nelson commented he provided two articles from Forbes magazine to the Committee related to safety of the public and remarked that it was his belief the safety of the public should be within the DCISC purview because of the harm to the public which would occur if DCPP were to shut down. He closed his remarks by stating the SWRCB proposal is just a way to shut down DCPP similar to what happened to SONGS and it should be rejected.
Ms. Sherry Lewis of MFP was recognized. Ms. Lewis stated that a disclaimer in the Evaluation would mean nothing as she would not believe it.
Ms. Rochelle Becker of the A4NR was recognized. Ms. Becker, who serves on the RCNFPP, stated the RCNFPP very much appreciates having the DCISC’s input and that the DCISC was formed for just such a role. She stated the DCISC was not initially invited to participate by the RCNFPP because the RCNFPP discussions were focused upon technology and then later upon economics. The DCISC was formed to assess and alert the public to safety concerns at DCPP. She remarked the DCISC has a different opinion than Bechtel concerning the need for a license amendment and no decisions have been made. Ms. Becker thanked the DCISC for supporting a request that the SWRCB support a webcast of its meeting on November 18, 2014. She stated that PG&E has also agreed to support a local webcast of that meeting and has offered to pay the cost which, Ms. Becker observed, would come from its ratepayers. In response to Dr. Budnitz’ inquiry. Ms. Becker confirmed that the invitation to the DCISC was discussed by the RCNFPP.
Mr. Pat Kelly, President of the Avila Beach Community Services District, was recognized. Mr. Kelly stated he was pleased that there was no offshore high energy testing performed as the local dungeness crab season proved to be the best in history. Mr. Kelly stated disturbing or destroying the marine mammal environment is not worth proving whether the plant is safe or not. Mr. Kelly inquired whether the water temperature, which he reported is currently higher than normal, has an effect on cooling. He remarked he was surprised to find the life of a dry storage cask was only 15 years and is now being extended to 20 years. He inquired how much it costs to change a dry cask but said he would not demand an answer of what that cost is over the 200,000 years that it will need to be addressed. He inquired who would pay for the waste created by DCPP and he suggested PG&E and its stockholders be required to contribute to an escrow account. Mr. Kelly stated that as DCPP is licensed to produce energy until 2024 after that date operation of the plant should cease. Dr. Budnitz replied that the efficiency of the DCPP cooling system is somewhat dependent upon the water temperature at the Intake Structure and the system is slightly more efficient when the ocean water is colder in the winter and accordingly the plant produces slightly less electricity during periods of warm ocean water due to the thermodynamic properties of the heat exchanger cycle. Dr. Peterson stated that dry cask storage at DCPP is licensed for 20 years but evidence indicates the casks could function effectively for approximately 100 years although the coastal environment at DCPP is more challenging to materials than an inland environment. Regarding the cost of storage, PG&E has a contract with the U.S. Department of Energy (DOE) that legally obligates the DOE to pay the cost for storage as the U.S. government is in partial default of these contracts by not beginning to accept the waste when it was contractually obligated to do so. The federal government is also under obligation to pay the cost for disposal of the fuel in consideration of the fact that PG&E previously paid a fee to the Nuclear Waste Fund. Dr. Peterson observed that the U.S. waste program has collapsed and is nonfunctional and therefore it is the federal taxpayers that will have to pay. Dr. Lam observed the NRC has a Waste Confidence Rule which means the NRC is fully confident and committed to licensing and operating a long term waste storage repository. Dr. Budnitz stated that the term of the license for dry cask storage is analogous to a state issuing a driver’s license for five years and then subsequently requiring a reassessment, reexamination and relicensing of the driver’s ability to drive. He observed that the duration of a license and the duration that something will remain safe are not the same thing and the NRC will be conducting a detailed evaluation before a license renewal or a new license for the ISFSI would be issued but until that process occurs no one knows whether engineering projections will be found to be correct. Dr. Lam stated he was sympathetic to the public concern over the period over which the waste will remain hazardous.
Ms. Simone Malbouef, a resident of Los Osos, California was recognized. Ms. Malbouef directed the attention of the Committee to, and she read from, an article by Mr. David A. Bunker which appeared in the Summer 2014 issue of the ‘Tahoe Quarterly’ which she stated contained revelations on the impact of the drawing out of ground water supplies in the California Central Valley and its impact on seismic activity. She reported that in some areas of the Central Valley land has dropped more than 28 feet due to the vacuum created by the evacuation of the aquifer. She reported the USGS has termed the sinking of the valley floor one of the largest alternations of land surface attributable to human activity and this activity has caused the Sierra Nevada and the California Coastal mountain ranges to rise and create more stress on seismic faults. Ms. Malbouef stated the earth’s crust is surprisingly elastic and over the last 150 years a volume of water equivalent to the water of Lake Tahoe has been drained from under the land in the Central Valley without any replenishment and water well drilling continues unabated. She commented she was surprised that emptying the Central Valley aquifer and the current drought conditions could affect mountains so dramatically and this is startling news for those in the local area living near 13 earthquake faults and serves as a reminder that the mountains, fresh water and the ocean are interconnected and she stated that we are just beginning to learn that this is the case. Ms. Malbouef stated the residents of Napa, California on August 24, 2014, experienced a 6.0 magnitude earthquake and she stated humans are not capable of predicting when an earthquake will occur or its magnitude and the same is true of tsunamis. She observed the accidents at Three Mile Island, Chernobyl, and at Fukushima were all the result of natural disaster, human error, or design flaws and natural disaster and human error are not within our control. However, destruction can be consciously mitigated by choosing to replace archaic and dangerous technology with safer more sustainable sources of power which support life on earth but do not threaten it, including solar, wind and wave technology which advance the creation of a world free of harmful effects of man-made carbon and radiation.
Dr. Peterson requested Mr. Cary Harbor, Director of Compliance, Alliance and Risk at DCPP to continue with the information presentations.
XXII Information Items Before the Committee
Mr. Harbor introduced the Engineering Supervisor for Digital Systems at DCPP Mr. Brian Maule. Mr. Harbor reported Mr. Maule has more than twenty years’ experience in the industry, holds a Bachelor of Science Degree in Electrical Engineering, and has experience in the Instrument & Control organization at DCPP.
Digital Control Systems Overview.
Mr. Maule introduced himself and stated he is a resident of the San Luis Obispo area and a Cal Poly graduate. He stated use of the term “digital” means that control functions have moved from electro-mechanical control to computer control, much like has been done with modern motor vehicles. This change from electro-mechanical to computers matters because the end result is that control systems have become more reliable, ultimately providing a safer operating plant. Mr. Maule reported there are three primary digital control systems at DCPP:
- Turbine Control System (in-service 2004)
- Feedwater Control System (in-service 2005)
- Process Control System (in-service 2012)
Mr. Maule stated the purpose of the digital Turbine Control System is to regulate the governor valve position which in turn controls steam flow during all modes of turbine operation. Essentially, the system controls the turbine generator during plant startup, normal operations, and plant shutdown. In response to Dr. Peterson’s observation, Mr. Maule confirmed the Turbine Control System has been digital for some time and was replaced in 2004 with a new digital system.
Mr. Maule reported the purpose of the Feedwater Control System is to automatically maintain SG water levels during steady-state operations. The system restores and maintains the water levels within safe levels during normal unit transients. Newer controls have reduced or eliminated operator interaction during system transients, preventing unnecessary plant trips, and simplifying operation.
Mr. Maule described the function of the Process Control System as to convert physical plant parameters such as temperature, pressure, level, and flow into electrical signals during normal operation. These signals are used for plant control (pumps, valves, heat exchangers, and tanks), operator indication, and computer monitoring and recording. He remarked that the recorded signals are used by Operations to trend parameters and also to provide a historical record which assists in identifying any system degradation.
Mr. Maule displayed computer ‘screen shots’ of the turbine control display and feedwater control display and a photo of the control board display. He described some of the control functions and their locations on the displays and stated that the digital displays are recreations of the previously used Westinghouse displays and therefore they remain familiar to the plant operators.
Mr. Maule described and discussed the common benefits and features of the Process Control Systems as follows:
- Common Benefits
- Common/shared platforms, inherent redundancy
- Cost savings (parts & labor)
- Reduced impact on maintenance
- Ease of redundancy
- Less maintenance required
- Flexibility—used for different systems
- Zero moving parts
- Common Features
- Triple redundancy
- System functionality not affected by module failure
- Faulted modules can be replaced online, thus maintaining uninterrupted control
- Built-in online diagnostics without additional external hardware or software
- Utilized in critical petroleum and chemical production plants
In response to Consultant Linnen’s question, Mr. Maule replied that redundancy is not required by regulation but is a design feature and redundancy is valued and used in the petroleum and the chemical industry as well as in the nuclear industry. He stated that all three process control systems share a common hardware platform and a flexible software commonality in that they are flexible as they function as logic controllers and are not similar to home-based computers. In response to Consultant Wardell’s inquiry Mr. Maule confirmed that the process control systems are safety-related systems. In response to Dr. Budnitz’ question Mr. Maule stated the systems are comprised of three separate modules, each processing the same signals and if one detects a fault the other two will continue to work.In reviewing the performance history for the process control systems Mr. Maule reported that none of the digital control systems he discussed have ever caused a unit trip at DCPP or at another nuclear power plant, lost their ability to perform a safety function, or caused an unplanned change in reactor power. As a result, the operators have an overall system that they can depend upon to safely and reliably control the plant under all conditions. Mr. Maule reported that recent upgrades include the process control system (in-service 2012) and the auxiliary control system (in-service 2006). He stated future upgrades are planned for the Condensate Polisher Control System and the Reactor Protection System, which he stated is not a control system.
In reply to Dr. Lam’s inquiry, Mr. Maule stated he has a total of seven people in his group, six employees and one contractor. He stated that his group does not do maintenance on the systems but rather maintains the data and tracks the replacements necessary to keep the process control systems operational. In response to Dr. Budnitz’ comment, Mr. Maule stated during refueling outages there is a goal not to have to touch the process control systems and therefore there is not a work overload during refueling outages for his group as most work on the process control systems is done offline without interaction with the control room. Mr. Maule confirmed Dr. Peterson’s observation that DCPP has been designated as a lead plant on replacement of its Reactor Protection System. In response to Dr. Budnitz’ inquiry, Mr. Maule replied that DCPP has more digital systems than most other nuclear power plants and is considered to be a leader in the area of digital systems and frequently consults with other plants to identify and solve problems which he stated provides valuable operating experience to DCPP.
Mr. Harbor remarked that from his previous experience as a control room supervisor he found the use of the digital process control systems to be extremely beneficial for the operators as the systems have protections built into them prior to actuation which greatly assist in avoiding human performance error.
Ms. Sherry Lewis, a representative of MFP and resident of San Luis Obispo, California was recognized. Ms. Lewis inquired what might happen if the computers described by Mr. Maule were somehow disabled and whether the possibility for human intervention in the process control systems existed. Mr. Maule replied that from a control systems perspective the situation described by Ms. Lewis was not an issue as the process control systems control the operation of the power plant but it is the Reactor Protection System which would operate to safely shut down the plant and the process control and Reactor Protection System are entirely separate systems by design and they do not interact. Dr. Peterson confirmed that there are many opportunities for human intervention to bypass a Reactor Protection System initiated shut down or ‘scram’ and the plant can be shut down automatically or manually and this dual functionality is required by NRC regulation.
Mr. Harbor introduced Mr. Jeff Harker, Maintenance and Technical Training Manager at DCPP. Mr. Harbor stated Mr. Harker has worked in the nuclear industry for 25 years, holds a Bachelor of Science degree in Nuclear Technology and has held positions in the Chemistry, Radiation Protection, and Training organizations at DCPP.
Maintenance and Technical Training Update
Mr. Harker stated he was proud to work at DCPP and recognized that his job includes the responsibility for safe operation of the plant and he described the DCPP workforce as a motivated group. He began his presentation with a review of its objectives which include describing the basic elements of the Maintenance and Technical Training Programs Strategic Plan, providing a timeframe for completion, highlighting actions completed to date, and describing results achieved and the ongoing monitoring efforts.
Mr. Harker stated training programs at nuclear power plants are required to be on a four-year accreditation renewal cycle. Operations training programs are on a separate cycle from Maintenance and Technical (M&T) training programs and this cycle is offset by two years with an onsite accreditation team visit scheduled in the interim between Operations and M&T cycles. The last Operations training program accreditation renewal was in January 2014. The next onsite Training Program Accreditation Team Visit (ATV) is scheduled at DCPP for the week of December 7, 2015, and Mr. Harker described this as a week-long evaluation visit in preparation for making a recommendation to the Training Programs Accrediting Board regarding the M&T training programs which are due for renewal in March 2016.
Mr. Harker described the origin of the M&T Training Programs Strategic Plan as including a Accrediting Board critique which was conducted immediately following the last Operations training program accreditation renewal. The results of this critique are captured as a self-assessment. Recommendations include developing a plan for M&T program renewal activities, scheduling and conducting mock boards to prepare for the process earlier, and holding a first board with internal members. The M&T program’s focus kickoff will be conducted to reenergize the group for the M&T programs and to demonstrate board experience to program owners and inspire line personnel to leverage training opportunities.
Mr. Harker discussed and described the contents of the M&T Training Programs Strategic Plan as follows:
- Challenge Statement
- Actions to Leverage Training Programs
- Organizational awareness of Board discussion
- Provide Systematic Approach to Training (SAT) refresher
- Routine communications to station personnel
- Training Staff Action
- Functional Organization Actions
- Strategic Communication Plan—Included in the Overall Plan
- Power History Events Analysis—Evaluated Against Training
- Contains each event in power profile
- Identifies Training activities associated with each event
- Update on an ongoing basis
- Reviewed at each Training Oversight Committee (TOC) meeting
In response to Dr. Budnitz’ inquiry, Mr. Harker described this as an across-the-board plan and he replied the Strategic Communications Plan is communicated to the DCPP workforce through the plant’s E-Connect communications network, within the training committees, and to the training oversight and advisory organizations. The TOC is comprised of plant senior leadership.
Mr. Harker described the training organization staff’s actions as including benchmarking to learn from the accreditation renewal process experienced by other nuclear power plants including South Texas, Callaway, Constellation, Entergy, and Wolf Creek; the development and implementation of a comprehensive process to prepare and issue an Accreditation Self Evaluation Report (ASER); prepare for the Accreditation Team Visit (ATV); prepare for the review by the Accrediting Board; as well as periodically briefing the TOC on industry findings; developing a peer review process through the STARS Alliance; and participating in industry self-assessments, ATVs, and mock boards at other plants. In response to Dr. Budnitz’ inquiry, Mr. Harker stated the Accrediting Board is made up of five members with extensive experience and gave as examples experience as ex NRC inspectors, senior executives from universities, senior executives from the airline industry. The ATV team is provided with the ASER which is then provided to the Accrediting Board. Mr. Harker reported other functional organizational actions at the departmental level include:
- Identifying at least one “training for performance improvement” item or aspect from 1R18.
- Identifying training successes resulting in better performance in 1R18.
- Rejuvenating the Performance Improvement Roll-Up process by review of Corrective Action Program documents, ensuring self-assessment techniques are used to identify opportunities and low level trends or issues are identified and addressed promptly.
- Identifying more than one benchmark or program in the next 12 months.
- Participating in industry mock boards to gain practice and experience
Mr. Harker stated the response to performance analysis requests of the DCPP Training Department is improving. He described the STARS Alliance accreditation renewal process as placing a focus on accreditation renewal by going from the critique stage to a process for the next fourteen months. Mr. Harker reported DCPP sponsored the creation of the STARS alliance document which is now used by the entire STARS Alliance. The STARS Alliance accreditation renewal process consists of three main sections addressing maintenance of the accreditation process including:
- ASER Development (tables with actions completed and to be completed)
- Station Preparations for ATV
- National Nuclear Accrediting Board
Nineteen separate attachments include check lists, lists of due dates, and owner-identified items. Mr. Harker reviewed the key ASER dates for the upcoming M&T Training Programs Strategic Plan which provides for the completion and issuance of the ASER (Rev 0) during the first quarter of 2015 and provides time for revision and review before issuance of ASER (Rev 3) by the end of the third quarter of 2015.
Mr. Harker reviewed the results achieved by the M&T Training Programs as follows:
- Heightened awareness in training committees
- TOC review of ATV preps (standard agenda item every quarter)
- Lower threshold for evaluating issues for training solutions
- Mechanical Maintenance performance improvement training for low level rework activities identified in1R18
- Process clarification through written guidance
- STAR’s Accreditation Renewal Process document
- Alignment with STARs partners
- Peer review of Comprehensive Self-Assessment Report and potential Station Identified Findings
- On-going monitoring primarily through all training committees
- Weekly phone call with directors and managers at other plants
Mr. Harker stated that the results involve a three-tiered approach with the Curriculum Review Committee consisting of students serving as the first tier, the Training Advisory Committee as the second tier, and the TOC as the third tier.
In concluding his presentation, Mr. Harker stated DCPP recognizes strong training programs are critical to the safe operation of the plant. DCPP has strong accredited training programs and a sustainable accreditation renewal process. Guidance is provided to help maintain accredited training programs. DCPP uses extensive industry peer involvement in multiple activities to help guard against isolation and encourage adoption of industry best practices. In response to Dr. Lam’s request, Mr. Harker identified the involvement of the students in the training process, using a process of analysis, design and evaluation, as the single most essential feature of a successful training program. Dr. Budnitz thanked Mr. Harker for a good report.
Ms. Sherry Lewis representing MFP was recognized. Ms. Lewis stated she had understood only the final portion of Mr. Harker’s presentation. Dr. Budnitz remarked that Mr. Harker provided information on the requirements for training and had described how the process to meet those requirements is successfully implemented at DCPP. Dr. Budnitz confirmed that it is the ATV team not the Accreditation Board that visits the plant and the accreditation process, while it is monitored by the NRC, is conducted by the nuclear industry.
Ms. Elizabeth Brousse representing MFP was recognized. Ms. Brousse inquired whether persons who have been trained at DCPP by its accreditation process could use or employ their accreditation at another nuclear power plant. Dr. Budnitz replied and clarified that the accreditation process is for plant programs not plant personnel. He observed that skills acquired at one plant would not be adequate without additional training if an individual were to be transferred to or employed at another nuclear power plant. He confirmed Ms. Brousse’s observation that Mr. Harker’s presentation was a discussion of an industry model for training accreditation.
Dr. Gene Nelson was recognized. Dr. Nelson observed he was impressed with Mr. Harker’s presentation and the process described by Mr. Harker as a living process with the lessons learned disseminated to ensure errors are not repeated. Dr. Nelson remarked that ‘Focused Learning’ is a company located in San Luis Obispo, California and Focused Learning was responsible for the development of the approach described by Mr. Harker as analysis, design and evaluation.
This concluded the informational presentations requested by the Committee from PG&E for this public meeting. Dr. Peterson expressed the thanks of the Committee to Mr. Cary Harbor and to all the PG&E personnel who attended and made presentations to the DCISC at this public meeting.
XXIV Concluding Remarks & Discussion By Committee Members Of Future DCISC Activities
The Chair requested Consultant Wardell to review the revisions made to the Evaluation of the Bechtel Addendum. Copies of the revised Evaluation in both its final proposed version and a version showing the changes made to the draft which was a part of the agenda packet for this meeting were distributed to the Committee and made available to the public at the same time. Mr. Wardell described the process he used to incorporate comments received from the Members, Consultant Linnen and Assistant Legal Counsel Rathie and the comments made by members of the public during the discussion of this matter earlier in the public meeting including the comments offered by Mr. Bill Powers on behalf of FOE. Mr. Wardell summarized the changes to the Evaluation which concerned the following:
- Statement by Mr. Powers that the NRC would defer to the State of California regarding a decision to require cooling towers in place of once-through cooling at DCPP. The DCISC does not fundamentally disagree with that observation but believes that the NRC will retain the ability to review such a proposal for its nuclear safety effect.
- Experience of the DCISC with NRC licensing activities. Information has been added to the Evaluation addressing this question.
- FOE’s comments regarding the effects of salt deposition from the use of saltwater by the proposed cooling towers. The Evaluation was revised to further address this issue.
- Risk to operational safety. The Evaluation was revised to clarify that the DCISC is primarily concerned with a risk to nuclear safety during the estimated six year period when both units are proposed to continue operations while construction activity occurs in the area where the south parking lot is presently located. The DCISC agrees the primary nuclear safety issue during the two year dual outage period is likely to be continued cooling to the plant’s SFPs.
- References to Hope Creek using saltwater for cooling. The DCISC’s research shows that the single unit at Hope Creek operates well but uses brackish water from the Delaware River estuary for cooling not saltwater. This brackish water is believed to have a salinity level approximately 1/3 that of saltwater.
- Salt deposition study taking into account the potential elimination of the Outfall and its effect on salt distribution location and rates. The DCISC agrees that in such a study related to the Outfall’s replacement by cooling towers this would be appropriate. However, the DCISC believes the impact of the Outfall on salt deposition at the plant is less than what would be produced by the proposed cooling towers.
- Conclusions in the Evaluation on the impact on nuclear safety. Changes to the Evaluation were made to references in terms of the likelihood of such changes having a potential to impact nuclear safety. The Evaluation retains the conclusion that everything presented to date for the DCISC’s review requires further study and analysis before any final conclusion or decision on any of the matters under consideration.
Dr. Lam stated he was comfortable with the revisions to the Evaluation as presented by Mr. Wardell but offered the following as an additional paragraph: “The DCISC’s charter is to review and make recommendations concerning the safety of operations at DCPP.” Dr. Lam stated his suggested revision was prompted by his sensitivity to public comment that the DCISC’s evaluation is being conducted outside of its charter, that by providing its evaluation the DCISC is doing another organization’s bidding, and that the DCISC lacks independence in this matter. Drs. Peterson and Budnitz accepted Dr. Lam’s proposed change to the Evaluation.
Dr. Peterson stated he remains sensitive to the concerns expressed by Dr. Lam, particularly to concerns expressed regarding the DCISC’s evaluation of certain design changes which were proposed in the interest of reducing cost. Dr. Peterson observed that the Evaluation’s review of cooling options includes reference to certain of the options being unlikely to generate significant nuclear safety concern. Dr. Peterson commented that concern with an increased risk of flooding may lie principally in that such a design change might trigger the need for a license amendment. Dr. Budnitz’ agreed but he remarked the change to the flooding risk still needs to be evaluated as a potential safety risk. Dr. Peterson remarked that the use of saltwater for makeup cooling is a significantly greater concern as there appears to be no similar use to serve as a precedent, with the Palo Verde plant in Arizona serving as the closest potential model but Dr. Peterson observed the salinity of water used by Palo Verde is less by a factor of three or four, the plant is located in different topography from DCPP, and the desert produces much lower humidity than DCPP’s coastal setting. Dr. Peterson observed the information provided by Mr. Powers concerning Hope Creek appears to have been inadvertently inaccurate and more investigation is needed on the issue of salt transport and its effects on safety related equipment and systems. Dr. Peterson remarked that the use of reverse osmosis to treat seawater should not be dismissed too soon as it need not be prohibitively expensive because the water to be produced need not be treated to a level greater than necessary to remove salt. Dr. Peterson stated that the DCISC differs from Bechtel in that the DCISC believes that the modifications to the DCPP cooling system suggested by Bechtel are very likely to require a license amendment from the NRC.
Dr. Gene Nelson was recognized. Dr. Nelson stated he was on the faculty at Cuesta College, had previously taught at Cal Poly, is a member of the group Green Nuclear Power, holds a Ph.D. in radiation biophysics and also has prior experience in the area of water treatment. Dr. Nelson expressed his opinion that the flooding issue discussed in the Evaluation would require a license amendment from the NRC and he commented it was the need for a license amendment that resulted in the closure of SONGS. Dr. Nelson noted that the proposal would require large amounts of water moving at a high velocity.
On a motion by Dr. Budnitz, seconded by Dr. Lam, with the incorporation of the amendment offered by Dr. Lam and the changes reviewed by Mr. Wardell, the Evaluation of the Bechtel Addendum was unanimously approved as amended and the Members directed the DCISC Legal Counsel’s office to transmit the approved Evaluation to the SWRCB and post it on the DCISC website.
On a motion by Dr. Peterson, seconded by Dr. Lam, the DCISC unanimously approved and directed, in response to a request by the Executive Director of the A4NR, that a letter be sent to the SWRCB expressing the support of the DCISC for the establishment of a location in San Luis Obispo County where the proceedings before the SWRCB on November 18, 2014, might be readily accessed by a live, real time, webcast made available to the members of the local community.
The Members and Consultants discussed with Ms. Zawalick confirming the dates in 2015 tentatively identified for future fact-finding, emergency response drills, and meetings of DCPP’s Nuclear Safety Oversight Committee. Dr. Peterson remarked the public tour during this meeting had fewer participants than usual and it was observed that as PG&E is again offering public tours which visit the protected area of the plant which are not currently a part of the DCISC tour and perhaps the format for the DCISC tour should be reviewed and revised. The Legal Counsel’s office was requested to obtain information on the number of persons who have recently toured DCPP and to review this information in context of the format for the public tour to be conducted with the DCISC public meeting in February 2015.
Ms. Sherry Lewis was recognized. Ms. Lewis stated the PG&E tour visits areas of the plant not a part of the DCISC public tour. Dr. Budnitz stated the PG&E and DCISC tours are not intended to be the same and that on the DCISC tour the public is accompanied by and has the opportunity to interact with the independent safety experts who serve on the DCISC. Dr. Budnitz stated the DCISC public tours are an important element of its mandate to conduct public outreach.
Dr. Budnitz stated he had just learned that the NRC will be releasing on the day following this public meeting its underground safety report for the Yucca Mountain proposed waste storage site in a version which does not include previous redactions and that the report will be available on the NRC’s website at 3:00 P.M. (EST) on October 16, 2014.
Dr. Peterson again expressed the thanks of the Committee to PG&E for its assistance with the informational presentations for this public meeting and to the technicians of AGP Video who recorded and live-streamed the meeting to the internet.
XXV Adjournment Of Seventy-eighth Public Meeting
There being no further business, the seventy-eighth public meeting of the Diablo Canyon Independent Safety Committee was adjourned by its Chair, Dr. Per Peterson, at 3:30 P.M.