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 B9, Minutes of the Diablo Canyon Independent Safety Committee February 4–5, 2015 Public Meeting (Approved at the June 16, 2015 Public Meeting)
Wednesday & Thursday, February 4–5, 2015, Avila Beach, California
Notice of Meeting
A legal notice of the plant tour and public meeting and several display advertisements were published in the Tribune and the Five Cities Times Press Recorder local newspapers, posted on the Committee’s website at www.dcisc.org and mailed to the media and those persons on the Committee’s service list. Information on the public tour, the legal notice and a copy of the meeting agenda were also posted on the Committee’s website. Public meetings of the Committee may be viewed online in real-time over streaming video at /www.dcisc.org and /www.slospan.org and are videotaped for later broadcast on the local government access television channel (Channel 21).
Public Tour of Diablo Canyon Nuclear Power Plant
The DCISC and 15 members of the public participated in a tour of Diablo Canyon Power Plant (DCPP). The group started off in the PG&E Energy Education Center for a brief introduction of the DCISC and its Members and Consultants. Afterward DCPP representatives made an information presentation about the plant. The group then boarded a bus for the plant, and on the way to the plant DCPP representatives discussed the history of the plant. Upon arriving at the plant, DCPP representatives took the group on a narrated drive-by of the Independent Spent Fuel Storage Installation (ISFSI), also known as the dry cask spent fuel storage facility.
At the plant proper the group split into two sub-groups, each with a DCPP escort and DCISC member/consultant accompaniment. Each group was processed through security and went into the plant. Wearing personal protective equipment (hard hats, hearing protection and safety glasses) and radio communications equipment, the groups took a narrated tour of the main turbine deck and window view of the control room. The two groups visited the Control Room Simulator, a true operating mock-up of the Unit 1 Control Room, separately for a discussion of how the plant operates, control room operators, and operator training.
The group then departed DCPP in the bus and had the opportunity to discuss the plant with individual DCISC members and consultants.
Conclude Public Tour
I Call to Order–Roll Call
The February 4, 2015, public meeting of the Diablo Canyon Independent Safety Committee (DCISC), the seventy-ninth 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 at www.dcisc.org and www.slospan.org and are videotaped for later broadcast on the local government access television channel (Channel 21). Dr. Peterson introduced and briefly reviewed the professional backgrounds of each of the other Members of the Committee. Committee Member Dr. Lam congratulated Dr. Peterson on his recent appointment to the position of Executive Associate Dean of the College of Engineering at U.C. Berkeley.
- Robert J. Budnitz
- Peter Lam
- Per F. Peterson (by teleconference)
Dr. Peterson introduced and briefly reviewed the professional backgrounds of the Committee's technical consultants, Mr. R. Ferman Wardell, P.E. and Mr. David C. Linnen and of the DCISC’s Legal Counsel Mr. Robert R. Wellington. Dr. Peterson also introduced Ms. Maureen Zawalick, Nuclear Generation Risk and Compliance Manager at DCPP, who ably assists the Committee Members, Consultants and Legal Counsel in their work and serves as the primary administrative liaison between the plant and the DCISC. Dr. Peterson observed technicians from AGP Video would be managing the streaming video broadcast of this public meeting and subsequently archiving the video on www.slospan.org or through the link to “Meeting Videos” on the Committee’s website and arranging for subsequent broadcast of the meeting on television.
III Public Comments and Communications
The Chair 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 this public meeting and he reviewed the advice from the agenda concerning items or issues which are brought to the attention of the members by the public during public meetings.
Ms. Rochelle Becker, Executive Director for the Alliance for Nuclear Responsibility (A4NR) was recognized. Ms. Becker stated she would be distributing a copy of proposed legislation to the Committee which would provide for the continuation of funding for emergency planning services after a nuclear plant is closed. Ms. Becker reported that funding from the State of California for offsite emergency planning services related to nuclear power plants is now scheduled to end in 2019. However, she observed DCPP’s two reactors are currently licensed to operate until 2024 and 2025 respectively. Dr. Budnitz commented the operating license for DCPP includes a condition for emergency planning. Ms. Becker asked that the DCISC consider encouraging PG&E to continue its offsite emergency planning activities at least until the end of the licensed life for both units and possibly longer for offsite storage of spent fuel. Ms. Becker reported that Southern California Edison has filed a request with the NRC to eliminate offsite emergency planning in 2019 for its now closed San Onofre Nuclear Generating Station (SONGS) and that PG&E has made a similar request for its now closed Humboldt Bay Power Plant.
Mr. David Weisman, Outreach Coordinator for A4NR was recognized. Mr. Weisman confirmed a comment by Dr. Budnitz that the license from the Nuclear Regulatory Commission (NRC) includes a condition for offsite emergency planning but Mr. Weisman observed that the funding for emergency planning services is provided through the California Public Utilities Commission (CPUC) in its rate making proceedings and it is that mechanism that is now scheduled to end in July 2020, after having been extended previously in 1999. Mr. Weisman questioned the wisdom of eliminating a law which provides a funding mechanism to implement the NRC’s emergency planning policy while reactors remain in operation.
Dr. Lam recognized California Energy Commission (CEC) Senior Nuclear Policy Advisor Ms. Danielle Osborn Mills who was present in the audience. Ms. Osborn Mills thanked the Committee for its commitment to making the DCISC’s meetings public and its attention to very important issues. She stated she was attending and representing CEC Chair Dr. Robert Weisenmilller and that Dr. Weisenmiller closely follows the activities of the DCISC. On behalf of the CEC Ms. Osborn Mills observed the DCISC provides an excellent public benefit and she thanked the Members for their service.
IV Consent Agenda
The Chair introduced the first item on the Consent Agenda, approval of the Minutes of the Committee’s October 14-15, 2014, public meeting held in Avila Beach, California. A draft of the October 2014 Minutes was included in the public agenda packet. Dr. Peterson expressed the appreciation of the Committee for the excellent quality of these Minutes. The members and consultants reviewed the Minutes, reviewed items for follow up action, provided clarification to Legal Counsel concerning typographical errors and the accuracy of certain references including the discussion on DCISC Recommendation R14-1 in the 24th Annual Report in the October 2014 Minutes and provided other editorial comments and substantive changes or clarifications concerning the draft of the October 2014 Minutes. Minutes of the Committee’s public meetings become part of its Annual Reports on Safety of Diablo Canyon Nuclear Power Plant Operations (Annual Report). On a motion made by Dr. Budnitz, seconded by Dr. Lam, the Minutes of the Committee’s October 2014 public meeting were unanimously approved subject to inclusion of the changes provided to the Committee’s Legal Counsel. The October 2014 Minutes will become part of the Committee’s 25th Annual Report.
V Action Items
A. Review of PG&E’s Response to the DCISC’s 24th Annual Report on Safety of Diablo Canyon Operations: July 1, 2013—June 30, 2014.
The Committee members then moved to accept PG&E’s response to the Committee’s recommendation (R14-1) in its 24th Annual Report. Recommendation R14-1 addresses reexamination of the significance of the role that DCPP’s Operations Department played and could have played to avoid the loss of power to Unit-2 (U-2) 4 kV Bus G during refueling outage 2R17. In his letter responding to the recommendation PG&E Senior Vice President and Chief Nuclear Officer Mr. Edward D. Halpin acknowledged on behalf of DCPP the role of Operations personnel in the loss of power to the U-2 4 kV Bus G and committed to a review of the root cause evaluation to ensure all aspects of the role of Operations in preventing a recurrence, including documentation by the Corrective Action Program of all causes, corrective actions, and gaps to excellence, will be addressed as to their effect on Operations processes and how the changes address Operations role in the loss of power to the 4 kV Bus G. Upon Drs. Peterson and Lam’s comment that the Committee will continue to monitor PG&E’s actions in response to R14-1, on a motion made by Dr. Budnitz, seconded by Dr. Lam the DCISC unanimously accepted PG&E’s response to Recommendation R14-1.
B. Update on Financial Matters and Committee Activities.
Legal Counsel Wellington reported that the balance of the operational grant funds for the Committee’s operations on hand from calendar year 2014 is expected to be approximately $50,000 and that these funds will be returned to the PG&E ratepayers who provide the funds for the DCISC’s operations. Mr. Wellington confirmed Dr. Budnitz’ observation that this will be the third consecutive year the Committee has returned funds to the ratepayers.
Mr. John Geesman, on behalf of the A4NR, was recognized. Mr. Geesman inquired how a deficit incurred in any year’s funding would be addressed by the Committee. Dr. Budnitz replied that such a deficit would be funded out of the following year’s grant funding. Mr. Geesman observed that the DCISC during calendar year 2014 expended a substantial level of extra effort in addressing the issue of the possible elimination of once-through cooling at DCPP and he suggested that in the future the DCISC would be required to expend an unprecedented level of effort to address seismic issues related to DCPP operations. Mr. Geesman cautioned the Committee to remain vigilant to ensure it has adequate financial resources to accomplish its mission as the work of the DCISC is appreciated by the public. Dr. Budnitz observed that for so long as he has been a member and before, the DCISC has never reduced its level of inquiry due to concerns over insufficient funding. Dr. Peterson commented that if the DCISC’s workload increases substantially on safety-related matters the Committee has an obligation to raise the issue with its appointing authorities, the CEC, the Governor and the state Attorney General, and to try to identify additional resources to accomplish necessary work.
The Members initially deferred scheduling of their future fact-finding and public meetings and returned to this task after the short break which followed the discussion below on the review of the Open Items List.
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 also follow up on issues, concerns and information identified for subsequent action during fact-finding or public meetings. Dr. Budnitz stated he had identified 16 items on the list which are scheduled to be reviewed during the first quarter of 2015 (1Q15) and as there is only a single fact finding scheduled with PG&E during that period some of these items will need to be deferred. Items discussed or concerning which action was taken included the following:
|TBD||How often spray from OTC has caused flashovers in past 10-year period & does DCPP see this as a safety problem (Per E. Brousse at October 2014 PM)||Include in Open Items|
|TBD||Data on measurement of radioactivity around DCPP (Per L. Seeley at February 2015 PM)||Schedule 3/15 FF|
|CM-13||Rev. Maint. Dept. Performance Measures/Staffing||Move to 1Q16FF|
|CM-14||Maint. Risk & Online Maint. Risk Procedures||Incorporate w/CM-10|
|HP-1||Human Performance||Move to 4Q15FF|
|HS-6||Safety Culture||Schedule 3/15 FF|
|EP-5||Use of Social Media||Schedule 5/15 FF|
|RA-5||PRA Programs to include Internal Flood PRA||Schedule 3/15 FF|
|RA-6||Seismic Fragility Analysis||Schedule 7/15FF|
|RP-12||Radiological Release Reports||Move to 3Q15FF|
|SF-2||Relative Risk - Cask & Pool Storage Incorporate ref. to Info. from D. Gilmore||Schedule 5/15FF|
|SC-3||Long Term Seismic Program||Schedule 3/15FF(SF)|
|SC-4||Risk-based Probabilistic Tsunami Hazard Analysis||Schedule 3/15FF(SF)|
|SC-8||External Flooding Study||Schedule 3/15FF|
|SC-9||Dr. R. Sewell Tsunami Report||Schedule 3/15FF & 6/15 PM|
|SC-10||Tornado Hazard Review (Combine w/SC-11)||Schedule 7/15FF & 10/15PM|
|SC-11||Firenado Hazard Review (Combine w/SC-10)||Schedule 7/15FF & 10/15 PM|
|FP-5||Fire Protection Program||Schedule 5/15FF|
|OT-6||NRC Work Hour Rules||Close|
|CL-1 thru 4||Closed Loop Cooling||Clean Up Wording & Retain Each Item|
|CL-5||Closed Loop Cooling||Delete (Same as CL-1)|
|BDB-6||FLEX Status||Review ESEP Schedule and Concentrate Seismic Damage|
|O-1||Observe Work Processes||Schedule 3Q15FF|
|O-3||Ops Role re 2R17 loss of U-2 4 kV Vital Bus G||Close & Open New Item re R14-1 Follow up|
|10/14PM-3||Emergency ASW Test||Tie-in /Testing in Inlet Cove & Receipt of State Permits|
|10/14PM-4||Design Quality Released to Field||Close|
|10/14PM-5||Seismic Fragility, Magnitude, Duration, Acceleration effect on SSCs||Close|
|10/14PM-6||Access following BDB||Close|
|10/14PM-13||Number of persons taking DCPP tours||Close|
|TBD||Review re Protected Area Tour Format||(Feb 15 PM)|
|TBD||Review re 6 New Areas of Uncertainty re Tornado Diagram||(Feb 15 PM)|
Certain other item numbers on the Open Items List for the February 2014 public meeting which were identified as “Close” and not otherwise discussed were approved for closure.
A short break followed.
VI Committee Member Reports and Discussion
A. Public Outreach, Site Visits and Other Committee Activities:
Dr. Peterson reported the tour held during the morning was the first to be held after 9-11-2001 on which the DCISC was able to bring members of the public inside the protected area of the plant. Due to requirements to pass through security the tour was limited to 15 members of the public and was fully subscribed. The Members discussed and directed the Legal Counsel’s office to work with PG&E to increase the tour to include up to 25 members of the public and to consider splitting the group into two subgroups to permit one subgroup to observe activities in the Simulator facility while the other subgroup clears security. The Members also directed review of the impact of scheduling public tours on Tuesdays when the Simulator is generally otherwise in use by PG&E for training. Members also observed that as PG&E is now conducting two or three plant tours each week, the demand for the DCISC tour may be reduced although they remarked that the public and the Committee both benefit greatly from the interaction afforded by the DCISC’s tours.
The members confirmed public meetings of the DCISC are now scheduled for June 16–17 and October 21–22, 2015, and February 3–4, 2016, and are all to be held at the Avila Lighthouse Suites in Avila Beach, CA. Fact-finding visits were confirmed and scheduled as follows:
-  March 30–31—April 1 (RJB/DCL); April 21–22 (PL/RFW); May 19–20 (PFP/DCL); June 10–11 (RJB/RFW); August 5–6 (PFP/DCL); September 29–30 (PL/RFW); November 18–19 ((RJB/DCL w/NSOC observation); December 9–10 (PFP/RFW).
-  January 19–20 (PL/DCL); March 16–17 (RJB/RFW) April 20–21 (PL/DCL). May 17–18 (PFP/RFW).
Dr. Budnitz reported that in August 2014 PG&E released for review the results of a multi-year seismic study which the DCISC has reviewed and which was also reviewed by the CPUC’s Independent Peer Review Panel (IPRP). Dr. Budnitz reported DCISC representatives have attended each of the three IPRP public meetings and have found the IPRP reviews to be helpful in understanding certain technical issues. Dr. Budnitz stated this was a prelude to the release by PG&E in March 2015 of its post Fukushima, NRC-mandated, Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 probabilistic seismic hazard analysis (PHSA). Dr. Budnitz reported in March 2015 PG&E will also release its NRC-mandated reassessment of the external flooding hazard at the plant site from precipitation, rivers or creeks, hurricanes, or tsunamis and the DCISC will be conducting fact-finding on both the seismic and flooding hazard studies prior to its June 2015 public meeting. Dr. Budnitz stated the NRC is also expected to convene a public meeting concerning the studies at a date to be determined later.
Mr. John Geesman, representing the A4NR, was recognized. Mr. Geesman commented that the latest version of the tornado diagram which ranks seismic hazards, as it was presented to the IPRP, disclosed for the first time six new items at the top of the diagram related to ground motion characterization all of which were rated substantially larger in their impact on the seismic hazard than any of the seismic source characterization items previously identified by PG&E and discussed during the presentation PG&E made to the DCISC at its October 2014 public meeting or identified in the report submitted by PG&E in August 2014, which Mr. Geesman termed the so called AB1632 Final Report. Mr. Geesman stated it was not known whether PG&E would address the six previously omitted items in the PHSA due to be released in March 2015. Mr. Geesman stated that PG&E Geoscientist Dr. Abrahamson’s statement that the items would be addressed in an update in ten years’ time suggests a level of temerity which no regulator should consider acceptable and nor should the DCISC.
Dr. Budnitz explained that in trying to understand the seismic hazard at DCPP it is important to consider the frequency with which earthquakes will occur and the size of those events. He remarked that these are different, although related, concepts and that the tornado diagram referred to by Mr. Geesman was a sensitivity demonstration from PG&E’s analyses of the sensitivity of how frequently seismic events occur and does not reflect how large any one event might be. Accordingly, Dr. Budnitz observed that if the plant is found to be strong enough to withstand any event which might occur, then the frequency of those events is not so important and accordingly there is a hierarchy between the size and the frequency of seismic events and the tornado diagram speaks to frequency not size. Mr. Geesman observed and Dr. Budnitz concurred that the way in which a site responds is a function of the way in which the ground motions are characterized. In response to Dr. Lam’s request, the Members directed that an item be added to the Open Items List to reviewing Mr. Geesman’s statement and to further reviewing issues related to the latest version of the tornado diagram provided by PG&E specifically with reference to the six new sources of uncertainty.
Ms. Sherry Lewis, a representative of the group San Luis Obispo Mothers for Peace (MFP) was recognized. Ms. Lewis stated she attended the November 2014 meeting of the IPRP and commended Dr. Blakeslee’s statement to the Environment and Public Works Committee of the California State Senate to the DCISC’s attention. She stated her understanding was that the term “Frequency” referred to ground frequency not how often a seismic event occurs. Ms. Lewis commented that Dr. Blakeslee states that as time has passed more and more seismic faults have been found in the vicinity of DCPP and faults that were known when the plant was built have been found to be larger and to have a capacity to link together. Ms. Lewis stated it was her opinion there were some shenanigans going on between PG&E and the NRC to hide the true extent of the hazard to make the plant appear to be safer than it is. She observed that for purposes of a seismic analysis there are very few data points which can be reliably applied to the plant site as only the Parkfield and San Simeon earthquakes were large earthquakes in the vicinity and they were located to the north and east and not within close proximity to the plant, while the Hosgri and Shoreline Faults are located to the south and west of the plant and are much closer. Ms. Lewis stated she has been attending meetings of the DCISC for years but is now beginning to question how honest people are being in making statements and presentations to the Committee and she observed that if the DCISC does not devote attention to these matters it is not doing its job.
Mr. David Weisman representing the A4NR was recognized. Mr. Weisman commented that the DCISC scheduling its follow up to the 2003 Tsunami Study by Dr. Robert Sewell in June 2015 was akin to conducting a postmortem on that study. He stated the tsunami assessment by PG&E which is due to be released in March 2015 is a separate probabilistic study, not a SSHAC process. Mr. Weisman stated that in his correspondence with Dr. Sewell, Dr. Sewell indicated that his preference would be for a Level 4 Tsunami SSHAC study. Mr. Weisman stated the DCISC appeared to be adopting a reactive rather than a proactive stance concerning Dr. Sewell’s tsunami study. Dr. Budnitz replied that in January 2015 the Committee conducted fact-finding on PG&E’s work on reviewing tsunamis which will be reported upon later in this meeting.
Ms. Elizabeth Brousse of MFP was recognized. Ms. Brousse stated that MFP recently hosted a “No Nukes California” conference to address issues of seismic and tsunami threats to DCPP, operation of the plant outside its design basis in violation of its operating license from the NRC, the impact of the use of once-through cooling, waste storage and the safety of the canisters used for dry storage of spent fuel. Ms. Brousse commended the work of Ms. Donna Gilmore of the group San Onofre Safety to the attention of the Committee concerning the effect of salt crystals on the spent fuel storage canisters which she stated had been found to cause corrosion and minute cracking and confirmed that sea salt crystals have been found on DCPP spent fuel canisters after only two years of operational life. Ms. Brousse stated that she learned that the canisters can fail after only 30 years and there is no current method available to mitigate defective canisters. She commented that San Onofre Safety is circulating a petition to stop California from wasting $400,000,000 on inferior nuclear waste storage canisters which may leak in 30 years. Dr. Peterson confirmed that the DCISC is familiar with Ms. Gilmore and her work and will be following up on the issues she has raised concerning spent fuel storage and that the DCISC has already identified salt deposition on the spent fuel canisters as an important safety issue. Dr. Peterson observed that he remembers being castigated recently for suggesting that the proposal to use saltwater cooling towers at DCPP to replace once-through cooling which would result in an increase in salt deposition at the plant site might cause safety issues.
Ms. Sherry Lewis of MFP remarked that salt on cooling towers would be addressed by frequent cleaning but there is no mechanism to clean inside the spent fuel canisters.
Dr. Budnitz confirmed that the term “frequency” is used as a term of seismic analysis in two ways. It is used to describe the frequency by which earthquakes occur and the frequency, expressed in Hertz, with which the energy arrives and that accordingly it is necessary to use care when using the term.
B. Documents Provided to the Committee:
The list of documents which are provided by PG&E on a monthly basis was included in the public agenda packet for the meeting. The list included all documents provided since the last public meeting of the DCISC in October 2014.
VII Staff-Consultant Reports & Receive, Approve and Authorize Transmittal of Fact Finding Reports To PG&E
The Chair requested Consultant Wardell to report on the November 19–20, 2014, fact-finding visit with Dr. Budnitz to DCPP. Mr. Wardell reviewed the topics discussed with PG&E during the November 19–20 visit as follows:
- Pressurizer Weld Overlay Issue - Mr. Wardell reported the Pressurizer is part of the Reactor Coolant System (RCS) piping and weld overlays were added to strengthen the nozzles. Only U-2 is affected by this issue. The work was subsequently inspected using ultrasonic testing (UT) techniques and passed. However, during 2R17 flaws were found using a more advanced UT inspection technique and U-2 was allowed to operate for one cycle while a root cause analysis was performed to support long term operation. That analysis was submitted and approved by the NRC and operation of U-2 was approved to 2045, with inspections required during outages to demonstrate that the flaws have not grown. The DCISC fact-finding team found this to be satisfactory.
- Containment Fan Cooler Unit (CFCU) Modification/Issues - the CFCUs operate to cool the atmosphere in Containment during normal and post-accident situations. Several years ago a problem with possible reverse rotation of the CFCUs was identified and anti-reverse rotation pawls were installed to protect the fan motors. Subsequently, some of these pawls required replacement as they were not made to tolerance and the plant committed to operate the CFCUs on low speed which was found to be adequate for both normal and emergency operation. Analysis is being performed to change the sequencing circuitry to permit a shift from high to low speed without damaging the motor or the shaft. Mr. Wardell stated the team recommends that the DCISC follow up on the corrective actions for the CFCUs after each outage.
- Fire Doors Update - Mr. Wardell reported that several years ago a number of fire doors were declared inoperable and compensatory fire watches were required by requiring personnel to frequently inspect the area near an inoperable door. The DCISC was concerned regarding the time taken to fully address this issue and Mr. Wardell reported a new program has now been approved for the fire doors and the DCISC should monitor this situation. Dr. Peterson observed that during the morning’s public tour PG&E personnel were attentive to ensure that each fire and security door was properly secured and Mr. Wardell observed that a failure to secure those doors requires a report be made.
- Intake Concrete Inspection and Repairs - Mr. Wardell reported the Intake structure is a concrete and steel structure located above the ocean and is inspected during each refueling outage for concrete or rebar damage due to its exposure to saltwater. During outages 1R18 and 2R18 inspections were performed which found very minor damage and repairs were made. The DCISC will review this issue following the next refueling outage.
- Safety System Functional Failures (SSFF) Update - SSFF failures affect or cause the loss of ability of a system’s safety function to shut down the plant and maintain the reactor in safe shutdown and to mitigate any accident. During 2010 and 2011 the number of SSFFs increased and a root cause evaluation was performed. The DCISC reviewed this issue in March 2014 and little progress was found. Since that time a new action plan has been developed and Mr. Wardell reported the trend in SSFF is slightly improving for U-2 and is steady for Unit-1 (U-1) and he described the results as disappointing. Mr. Wardell stated the fact-finding team has a recommendation that DCPP review this issue and the causes of SSFF and DCPP’s efforts to take action to reduce the number of SSFFs to near zero.
- Outage 2R18 Results - Mr. Wardell reported the plant met all its goals for 2R18 and he described it as a very successful outage with no nuclear safety events or concerns.
- Radioactive Waste Systems Review and Walkdown - Mr. Wardell reported there are three component systems used to address gaseous, liquid and solid radioactive wastes. The Radioactive Waste System is currently rated in White2 health status with minor issues identified. The DCISC team toured the system with the system engineer and found the systems were working properly and the plant condition in those areas was good.
- Equipment Qualification Program Update - this program addresses mostly electrical equipment which must be qualified for normal and post-accident environmental conditions when radiation, temperature, humidity and pressure could increase substantially. The system was in White status due to personnel changes due to retirement and departure of engineers and when new engineers are assigned to a system the system’s health is accordingly downgraded until the assigned personnel have achieved a certain number of years of experience with their respective systems. Dr. Budnitz observed that this downgrade is not related to any system deficiencies related to its functional capabilities.
- Steam Generator (SG) Performance and Inspections through Outage 2R18 - Mr. Wardell reported that the SGs for both units were replaced, in 2008 for U-2 during 2R14, and in 2009 for U-1 during 1R15. The new SGs have been operating very well since that time and the SG tubes, which separate the primary (radioactive) and secondary (non radioactive) systems, are inspected for leaks or indications of leaks using UT techniques with only very minor flaws found and with sludge lancing performed on the secondary side producing only three pounds of sludge due to corrosion or metal in the four U-2 SGs.
- Radiation Monitoring System Long Term Strategy - the Radiation Monitoring System monitors radiation in systems and components within and outside of the plant. Some components, which are both digital and analog, date from the 1970's, 1980's and 1990's but Mr. Wardell reported they are not considered obsolete as parts remain available. However, there have been reliability and availability problems with the Radiation Monitoring System and corrective actions have been taken and a long term strategy is now being developed and is due for completion in April 2015. The system is currently in White health status and Mr. Wardell recommended the DCISC follow up on the long term strategy for this system in the third quarter of 2015.
- Observe NSOC Summary Session - Mr. Wardell reported the Nuclear Safety Oversight Committee (NSOC) consists of five external (to PG&E) high-level nuclear industry leaders who regularly visit DCPP for three and one half days, three times per year, to observe plant activities, review work, and reports. A summary meeting is conducted on the final day of each NSOC visit to review functional areas, major projects, outage work, work management, etc. The DCISC has agreed with PG&E to protect information received from DCISC observations of NSOC meetings and review of NSOC reports in order to protect an open dialogue between PG&E, the NSOC, and the DCISC. Mr. Wardell reported the DCISC team observed the NSOC meeting on November 20, and concurred with the findings and conclusions of the NSOC.
- Meet with NRC Resident Inspector - the DCISC representatives met and had a useful discussion with the NRC Resident Inspector concerning the tsunami study by Dr. Sewell, progress on the seismic hazard analysis, and the main steam valve replacement event.
- DCISC Member Meeting with PG&E Chief Nuclear Officer - following the fact-finding Dr. Budnitz met with Mr. Halpin to review the results of the fact-finding visit and certain other matters.
Ms. Elizabeth Brousse of MFP was recognized. Ms. Brousse stated she had a concern about the Radiation Monitoring System as this topic came up recently at the MFP’s recent conference and she stated people are buying Geiger counters to monitor radiation but there are questions as to the accuracy of those Geiger counts. She inquired whether PG&E might consider regularly reporting regarding the radiation levels emitted by DCPP’s operations. Dr. Peterson responded and stated that Professor Kai Vetter and Prof. Vetter’s students at U.C. Berkeley have been monitoring radiation levels but radionuclides released from the Fukushima accident can only be detected at specific energies and this requires very sensitive instruments that have the ability to discriminate and generally liquid nitrogen-cooled germanium radiation detectors are used for this purpose. Generally, a Geiger counter would not be able to detect radiation from DCPP operations as the variability of background radiation would greatly exceed any amounts of radiation produced by DCPP. Mr. Wardell and Mr. Linnen observed that the DCISC’s Annual Reports contain information based on the information PG&E provides annually to the NRC on radiation emissions from DCPP and the environmental studies done around the plant have detected only minuscule amounts of radioactivity which are significantly below the technical specification limits established by the NRC based upon impact to the environment.
Following Mr. Wardell’s report and the public comment following, on a motion made by Dr. Lam seconded by Dr. Budnitz, the November 19–20, 2014, Fact Finding Report was unanimously approved and its transmittal to PG&E authorized.
The Chair requested Consultant Wardell to continue his report by reporting on the items covered during the January 21–22, 2015, fact-finding visit to DCPP with Dr. Lam. Mr. Wardell reviewed the topics discussed with PG&E during that visit as follows:
- Fukushima FLEX Quick Hit Self-Assessment - Mr. Wardell reported FLEX is a descriptive term (not an acronym) for the portable equipment being put into place to provide the ability to tie-in electrically or mechanically, by piping or wiring, to components which may have failed during a Fukushima-type event. The DCISC fact-finding team reviewed DCPP’s compliance with industry standards and NRC requirements for FLEX and found the FLEX initiative to be in compliance and on schedule to meet implementation dates of October 2015 for U-1 and May 2016 for U-2 for the required equipment, communications, lighting, wiring, procedures, training and testing. Mr. Wardell reported the NRC is expected to conduct a full inspection of FLEX in late 2016. He reported the quick hit self-assessment was well done and the recommendations and findings were placed into the plant’s Corrective Action Program to be formally tracked. Mr. Wardell suggested the DCISC again review FLEX in November 2015 regarding its implementation for U-1.
- Seismic Studies & Submittal to NRC - this review was in follow up to an issue raised by Mr. Geesman on behalf of A4NR during the DCISC’s June 2014 public meeting with reference to concern about PG&E’s interactions with the NRC, as the federal regulator, concerning a final seismic report to be submitted to the Atomic Safety and Licensing Board (ASLB). The DCISC team concluded the analyses of the seismic and tsunami hazard appeared to be appropriate. Dr. Lam commented that fact-finding team found PG&E was on schedule to make reports on these matters to the NRC, in response to a 10 CFR 50.54(F) letter, and he was informed there was no ASLB proceeding pending and that PG&E was not planning any submittal on these issues to the ASLB.
- Clearance Process Performance in 1R18 & 2R18 - Mr. Wardell reported the clearance process is used to document when equipment has been cleared for mechanical, electrical or other work such that there is no safety hazard from the work to employees or to other plant components. The DCISC representatives reviewed the clearance process used for 1R18 and 2R18 and found only minor clearance error issues. One issue was what Mr. Wardell described as middling significance concerned a red tag indicating Maintenance clearance being mistakenly posted for an Operations procedure and he commented PG&E has taken this matter very seriously to ensure the situation does not repeat.
- Performance Improvement Program Performance - this program includes the Corrective Action, Benchmarking, and Self-Assessment Programs and Mr. Wardell stated DCPP is making major changes in its Performance Improvement Programs based on industry guidelines to focus more on prevention and less on administrative requirements. The DCISC team reviewed the new procedures which appear to be sound but the team recommends a future fact-finding be held to review implementation of the program and its results in order to determine its effectiveness. Mr. Wardell reported the human error rate at DCPP is decreasing and further improvement in the Performance Improvement Program could lead to other improvements in the plant.
- Component Review - Reactor Coolant Pumps - the Reactor Coolant Pumps (RCP) are used to pump water around the RCS to cool the core, provide heated water to the SGs, and to return the water to the nuclear vessel. Mr. Wardell stated the RCPs are working well and have a triple seal to eliminate or control leakage from the pumps which injects seal water into the seals and to return pre-designed amounts of seal leakage back to the seal injection system. Mr. Wardell stated that these seals do fail periodically, often due to debris, and this is usually indicated by increased leakage and it requires a plant shutdown to inspect the seals if the amount of leakage exceeds a certain amount. This inspection is resource intensive and occurs in a high radiation area. DCPP maintains a mockup of a RCP with its seal package in its Mechanical Maintenance Training facility and the DCISC team reviewed the procedures for replacing and aligning RCP seals. DCPP will replace all its RCP seals with an improved Westinghouse passive thermal shutdown seal which he described as more rugged than the current seals and that includes a feature such that if the station were to lose power the seal leakage would not increase. Mr. Wardell recommended that the DCISC monitor the installation of the new RCP seals at a future fact-finding.
- Single Point Vulnerability Program - was reviewed by the DCISC fact-finding team.
- Reactor Vessel Material Surveillance Program - Mr. Wardell stated the bombardment of a reactor vessel by neutrons over a protracted period can cause a pressure vessel to become embrittled and accordingly specimens made of the same material as the vessel and its welds are placed within the vessel and are removed and tested periodically. These specimens experience the same neutron fluence as the vessel and destructive testing provides an indication of the parameters of the reactor vessel with reference to embrittlement which in the event of a sudden drop in temperature at high pressure could cause flaws in the vessel to open suddenly. He reported the Low Temperature Over-Protection System is available to prevent the pressure from increasing if the temperature of the vessel drops. Mr. Wardell reported fracture toughness analyses for both DCPP units indicate the respective vessels are both in good shape for the end of the life of the plant out to 2024 and 2025, as well as for an additional 20 years should DCPP receive approval from the NRC for a license extension. Dr. Lam observed previously under NRC rules only Unit 2 would have been eligible for an extension of 20 additional years but under a new voluntary rule that option is now also provided for Unit 1.
- Trouble Shooting Program Implementation - Mr. Wardell stated that in the past the DCISC found the Troubleshooting Program to be fairly complex and hard to understand. A new procedure has simplified the program’s procedures. The DCISC team reviewed two examples of the new Troubleshooting Program procedures. The first example involving pressurizer heaters went well while the second example involving a generator differential relay took several approaches to find the problem. Mr. Wardell stated this was expected as the problem was complex and the Troubleshooting Program appears to be improved.
- DCPP State of the Plant - the DCISC will receive a presentation on this topic later during this public meeting and Mr. Wardell deferred his discussion.
- Potential Gas Intrusion into the Containment Spray System - spray headers are used by the Containment Spray System to reduce temperature and pressure after an accident which generates steam, heat and pressure. The system takes its initial suction from a tank which contains sodium hydroxide which is used during injection for radioactive particle control. At other nuclear plants it has been found that if this tank went dry air could be introduced into the Containment Spray System resulting in a condition of gas intrusion into the system and DCPP identified this operating experience as one which could potentially affect the plant. Westinghouse performed a prompt operability assessment which determined the void fraction in the containment spray pump sump suction to be less than 2% which would not pose an operability issue for DCPP. However, the licensing basis for the plant assumed 0% void fraction. The NRC determined that DCPP had not taken action quickly enough and issued a non cited violation (NCV). DCPP has addressed the immediate problem and has changed the system that keeps track of licensing issues to ensure adequate priority is assigned to this type of issue so that the issue should not recur.
- Meeting with NRC Senior Resident Inspector - the DCISC fact-finding team discussed with NRC Senior Resident Inspector Mr. Thomas Hipschman the NRC inspection schedule, flashover events, and the gas intrusion into Containment issue, as well as the fact-finding agenda. Dr. Lam stated he found his meetings with the NRC Senior Resident to be extremely useful particularly as to learning about the NRC’s inspection priorities.
- DCISC Member Meeting with PG&E Chief Nuclear Officer - Dr. Lam met with Mr. Ed Halpin to discuss the fact-finding and other items of mutual interest.
Mr. John Geesman representing A4NR was recognized. Mr. Geesman stated he agreed with the Committee’s action to close out review of the report to the ASLB on seismic issues as the concerns he expressed at the June 2014 DCISC public meeting were now moot. However, Mr. Geesman stated that Dr. Lam had been misinformed concerning the existence of a pending ASLB proceeding, as there is a proceeding pending which plays a large role in the state-funded seismic studies and an ASLB panel remains convened to study and consider the extension of DCPP’s two operating licenses. He reported that while the ASLB suspended the proceeding in June 2011 to enable PG&E to complete the state-funded studies, for which the CPUC authorized $64,250,000 of ratepayer funds, the report PG&E submitted in August 2014 as its final report on the seismic studies was directed to the ASLB and in every month since June 2011 PG&E has provided updates to the ASLB on the progress and timing for those studies. Mr. Geesman stated the concern he expressed in June 2014 concerned a subsidiary issue regarding a letter from NRC staff which enabled PG&E to withdraw a License Amendment Request to change the design of the plant which commented upon PG&E’s characterization of the ground motion associated with the maximum credible earthquake on the Shoreline Fault as bounded by the ground motion response spectra established in the Hosgri evaluation some years earlier. In that letter the NRC required PG&E to report on an interim basis any new information it may receive concerning the Shoreline Fault in terms of its greater capability. Mr. Geesman stated the A4NR has discovered the existence of emails between Mr. Halpin and his staff from 2013 wherein it is indicated PG&E had concluded the Shoreline Fault was in fact longer than previously thought and that it was linked to other fault such that a joint rupture with the Hosgri Fault was possible which was contrary to earlier reports on the Shoreline Fault. Mr. Geesman stated PG&E delayed informing the NRC of this conclusion for 14 or 15 months until it submitted the AB1632 studies to the ASLB in August 2014 wherein this conclusion was addressed and during that time PG&E continued to maintain the Shoreline Fault is bounded by the ground motion response spectrum associated with the Hosgri Fault, which Mr. Geesman described as a very controversial question. Mr. Geesman stated his dissatisfaction with the way in which PG&E and the NRC have handled this matter. Dr. Lam thanked Mr. Geesman for his clarification and stated his understanding that the letter from PG&E to the NRC regarding the relicensing had placed the matter in abeyance with the ASLB and that from Mr. Geesman’s statement he would assume that the sitting Licensing Board is still in the process of accepting modifications without taking any action on the pending issue.
On a motion made by Dr. Peterson seconded by Dr. Budnitz the January 21–22, 2015 Fact Finding Report was unanimously approved and its transmittal to PG&E was authorized.
The Chair requested Consultant Linnen to report on the December 2–3, 2014, fact-finding visit to DCPP with Dr. Peterson. Mr. Linnen reviewed the topics discussed with PG&E during that visit.
- Status of Large Station Transformers - Mr. Linnen reported the DCISC fact-finding team observed a continuing and increasing focus by the station on ensuring the reliability of large station transformers and PG&E will be making a presentation on large station transformers at this public meeting.
- Foreign Material Exclusion (FME) Program - the purpose of the FME Program is to prevent undesired and potentially harmful materials from entering plant systems. DCPP tracks and records FME events and grades performance on a monthly basis. DCPP has generally maintained the same level of improved performance observed during the DCISC review of the FME Program in 2012. Mr. Linnen observed workers were encouraged to immediately report impediments to error-free work and this engagement of the workforce appears to be a contributor to improved performance.
- DCISC Follow-up on Response to State Water Resources Control Board (SWRCB) Initiative on Closed Loop Cooling - Mr. Linnen reported the DCISC has been very active in reviewing issues involved with the potential elimination of once-through cooling at DCPP, most recently on the potential implications on plant operations from the installation of cooling towers using saltwater south of the plant site. Dr. Peterson commented that the DCISC will also follow up concerning any changes in the flooding hazard from the current flooding hazard assessment for circulating water in the Turbine Building which would be one of the potential safety impacts.
- Office/Personnel Seismic Safety - Mr. Linnen commented this issue is similar to that addressed by the Seismically Induced System Interaction Program which addresses the potential for plant systems and components to be impacted during an earthquake. The DCISC’s emphasis on office and personnel seismic safety recognizes that the effect of an earthquake can potentially impede access within the plant or injure key personnel who would be required to respond to off-normal conditions. Mr. Linnen stated the fact-finding team found office and personnel seismic safety at PG&E to have improved.
- Residual Heat Removal (RHR) System - the RHR System is a safety-related system used to transfer heat during the latter part of plant cool-down from the RCS to the Component Cooling Water System at a controlled rate. The RHR System health was rated Green for U-2 and White for U-1. An open item affecting both units was the need to have actions completed by a test lab regarding the recirculation of coolant in the aftermath of a potential loss of coolant accident (LOCA) to ensure the coolant is not impeded by debris impinging on the screens to the containment sump.
- Maintenance Training Program - Mr. Linnen stated the DCISC representatives found the Maintenance Training Program to be extremely structured, very in-depth and well implemented.
- Management Observation Program - this program provides for observation and a critique by directors and leadership of workers during performance of work in the plant. Mr. Linnen reported this program has been made more interactive to create an environment which provides an opportunity for support and feedback as well as a critique.
- Status of the Independent Spent Fuel Storage Installation (ISFSI) - Mr. Linnen began his description of the fact-finding by reviewing the expansion of the ISFSI from two to seven storage pads and he reported that the DCPP Quality Verification (QV) organization is very active in its oversight of this project. Mr. Linnen reported the ISFSI expansion appears to be proceeding in a well-managed manner. Mr. Linnen confirmed the fact-finding report recognized that after the visit an issue emerged concerning the potential for stainless steel to be susceptible to chloride stress corrosion cracking, pitting corrosion, and crevice corrosion when exposed to certain environmental conditions and the DCISC will pursue the potential impact of atmospheric chlorides on carbon steel and stainless steel structures used in the ISFSI canisters and overpacks and on other equipment on the DCPP site. In response to Dr. Budnitz’ inquiry, Mr. Linnen confirmed that the corrosion issue does not constitute an imminent or immediate problem and the DCISC will receive a presentation on the ISFSI at this public meeting.
- Flexible Power Operations - Mr. Linnen reported nuclear power plants were generally intended to run at 100% power generation and now some plants are reviewing operation at varying power levels in response to demand for electric power. The fact-finding team learned that no decisions concerning flexible power operations at DCPP have been made and the DCISC will continue to monitor this issue. Dr. Peterson commented that there is now less probability for flexible power operations at DCPP due to grid demands. Dr. Budnitz observed that flexible power operation if not done correctly can represent a safety compromise and the DCISC should remain vigilant to assure it understands the effect of flexible power operations at DCPP.
- Update on Tsunami Hazard - Mr. Linnen reported the tsunami hazard analysis includes not only tsunamis generated by distant sources but also includes near-source tsunamis which could be produced by large underwater landslides in the vicinity of DCPP. He reported the studies were not complete at the time of the fact-finding visit but are being actively pursued by PG&E and will be documented by the tsunami hazard assessment scheduled to be submitted to the NRC in March 2015 which will include three-dimensional models of the bottom of the sea floor. In response to Dr. Budnitz’ inquiry, Dr. Peterson stated the DCISC fact-finding team did not receive any specific detail about the results of the tsunami analysis that would lead to a conclusion that the hazard is significantly greater than previously thought. The DCISC will review the PG&E tsunami hazard study when it is available as well as the tsunami study prepared by Dr. Robert Sewell in 2003 and assess the implications for safety. Dr. Peterson commented the major uncertainties do not have to do with distant tsunamis but rather with potential submarine landslide induced tsunamis and a principal question relates to the location and how large an area could be affected by such a landslide. Dr. Peterson observed there is a credible possibility that a tsunami could disable the Auxiliary Saltwater System (ASW) even if it did not exceed the height of the ASW snorkels due to debris deposit but this would not be difficult for a plant to cope with. A tsunami in excess of 85 feet could impact DCPP’s diesel generators which could be managed by the application of FLEX equipment, while a tsunami exceeding 140 feet could affect the plant’s battery systems. Tsunamis also have the potential to severely impact the coastal area around DCPP and it is possible that the time available to evacuate low-lying areas or to ramp down power operations at DCPP could be very short. Dr. Peterson stated understanding the potential for a landslide-induced tsunami was an important area for the DCISC to continue to study in more detail to understand the actual risk but at this point the DCISC does not have sufficient information to reach any conclusions. He remarked that experiences in Japan after the March 2011 earthquake and tsunami demonstrated a lack of preparation not only by the Japanese nuclear power plants but also in the capacity in Japan to warn and evacuate the population. Dr. Peterson confirmed that while the DCISC fact-finding team did not review Dr. Sewell’s tsunami study with PG&E, PG&E is aware of that study and is working with the study’s conclusions. Dr. Lam expressed his appreciation and the thanks of the Committee to Mr. David Weisman and the A4NR for bringing the Sewell study to the attention of the DCISC. Dr. Budnitz reported that PG&E initiated a tsunami study in 2008 by the Pacific Earthquake Engineering Research Center at U.C. Berkeley and that this report was published in 2010, but the report is not specific to DCPP and lacks detail. Accordingly, and at the direction of the NRC, PG&E commissioned the study that is to be released in March 2015.
Dr. Budnitz observed that at the present time the design basis for tsunamis was based upon a very large tsunami which might cross the ocean and its purpose was to demonstrate that the plant design is robust against this threat but when the current design basis was developed the possibility of a tsunami developing due to a slump in the nearby continental shelf was not considered. Dr. Budnitz stated that a near-generated tsunami could be as large as one generated at a distance and the warning time for a near-generated tsunami would be very short or nonexistent. He remarked that nuclear plants are designed to trip offline automatically upon the occurrence of earthquakes of a certain size but this is based upon different considerations than those created by a near-source tsunami and he remarked the industry and DCPP will need to look carefully at this issue including deciding whether the plant should be automatically tripped offline upon occurrence of a lesser earthquake.
- Meeting with NRC Senior Resident Inspector.
- DCISC Member meeting with PG&E Chief Nuclear Officer.
Mr. John Geesman on behalf of A4NR was recognized. Mr. Geesman stated that it was the action of the DCISC in making its Freedom of Information Request to the NRC that prompted the NRC to release Dr. Sewell’s 2003 Tsunami Study. He stated that by retaining and not releasing that study the NRC engaged in the type of misconduct which has led to its discredited status among people in California and he expressed thanks to the Committee for its persistence. Mr. Geesman requested Dr. Peterson to comment further on his remarks concerning grid conditions making flexible power operations less likely and he inquired whether the Committee members had the opportunity to review the report by the Areva firm on this subject. Dr. Budnitz confirmed he has reviewed the Areva report and Dr. Peterson stated he had not done so. Dr. Peterson stated that qualitatively it appears less likely that flexible power operations will take place at DCPP although he stated nuclear power plants in France routinely operate in that mode. However, in order to do so Dr. Peterson stated it is necessary to make appropriate modifications to equipment. He further observed that at DCPP power generation operations are routinely reduced to clean the circulating water system or because of winter storm activity.
Dr. Gene Nelson was recognized. Dr. Nelson stated he serves on the Physical Sciences faculty at Cuesta College. Dr. Nelson stated he found Dr. Sewell’s 2003 Tsunami Study to be speculative and beyond the state of the art. Dr. Nelson observed that scree slopes are above ground manifestation of the angle at which material accumulates and in an environment that is subject to frequent shaking from earthquakes. With large earthquakes occurring approximately every 350 years in the local area, the idea of having a so-called 40-mile event strains credulity. He remarked that due to this frequent shaking, material in the local area is at the angle of repose all the time and does not accumulate such that mass accumulations could generate a large tsunami. Dr. Nelson stated he provided a report by the group Californians for Green Nuclear Power to the DCISC for review, and Appendix A of that report includes recommendations regarding the importance of DCPP in fighting greenhouse gas emission. Dr. Nelson stated he was pleased the State Water Resources Control Board (SWRCB) recognized this as a key benefit of DCPP and he contrasted this with the closure of SONGS which he stated has resulted in millions of tons of carbon being released into the atmosphere. Dr. Nelson stated that renewable sources of power such as wind and solar cannot have a meaningful impact on meeting the demand for power in California. Dr. Nelson stated that to replace DCPP would require 300 square miles of land to be covered with wind turbines and the wind blows intermittently. He remarked a new solar thermal power plant located at Ivanpah, California, must run its gas-powered boilers on the average of four and one half hours every day. Dr. Nelson closed by asking the DCISC to do everything in its power to encourage the SWRCB to adopt the recommendation in Appendix A of the report.
Dr. Peterson thanked Dr. Nelson and the other members of the public for their comments and remarked that the principal review activities of the Committee relative to the issue of cooling towers are related to their potential impact on safety.
Legal Counsel Wellington stated that upon their approval fact finding reports are made available to the public and become part of the Committee’s next Annual Report.
Upon a motion by Dr. Lam, seconded by Dr. Budnitz, the December 2–3, 2014, Fact Finding Report was unanimously approved and its transmittal to PG&E authorized.
Copies of correspondence sent and received at the office of the Committee's Legal Counsel since the last public meeting of the Committee in October 2014 were included with the public agenda packet for this meeting.
IX Adjourn Afternoon Meeting
The Chair adjourned the afternoon meeting of the DCISC at 5:45 P.M.
X Reconvene For Evening Meeting
Dr. Peterson convened the evening meeting of the DCISC at 5:55 P.M.
XI Committee Member Comments
There were no comments by any Member at this time.
XII Public Comments and Communications
Dr. Peterson invited any member of the public to attend this public meeting and to address comments to the Committee.
Ms. Gina Mori was recognized. Ms. Mori stated she was a new attendee at the DCISC’s public meetings and she stated it was her observation that each of the DCISC members has a background in nuclear energy and she acknowledged that was needed in order to fulfill their role but she questioned why the Committee should not include representatives who do not favor nuclear power in order to get different opinions.
Dr. Gene Nelson, a member of the Cuesta College faculty, was recognized. Dr. Nelson stated he has a Ph.D. in biophysics and he observed most people’s knowledge of nuclear power is not informed by knowledge of physical science, engineering or mathematics but rather by works of fiction. Dr. Nelson remarked that many persons base their opinions about nuclear power on these works of fiction. Dr. Nelson stated he is working to inform people about basic science and engineering so that what goes on at DCPP would not be so much of a mystery. Dr. Nelson remarked that informing the public and making people aware of the facts about nuclear power is part of safety as doing so could avert panic and he stated there is, overall, a great need for more education. He closed his remarks by stated that he hopes the DCISC endorses the concept of improving public outreach and general knowledge on nuclear safety issues.
Ms. Sherry Lewis, a representative of MFP, was recognized. Ms. Lewis stated that members of her group and of the A4NR have scientific knowledge and do a great deal of research and study on issues related to nuclear power. Ms. Lewis stated she has attended several SSHAC workshops, meeting, as well as meetings of the IPRP and the SWRCB.
The Chair thanked the members of the public for their comments.
XIII Information Items Before the Committee
The Chair introduced Mr. Cary Harbor, Director of Compliance, Alliance and Risk at DCPP and who will introduce the PG&E presenters this afternoon and assist and respond to Committee inquiries. Mr. Harbor thanked the members of the public for attending and for their interest. Mr. Harbor stated PG&E encourages participation and values all perspectives. Mr. Harbor stated education is a key value of PG&E and DCPP is increasing its tour program in response and conducting outreach in the local community on the value of DCPP for all parties involved. Mr. Harbor then introduced Mr. John MacIntyre, Director of Maintenance Services at DCPP. Mr. Harbor reported Mr. MacIntyre has more than 30 years of nuclear industry experience. Mr. MacIntyre has held leadership positions in the Quality, Operations, and Training organizations and holds a Bachelor of Science Degree in Nuclear Technology and a Senior Reactor Operator’s License.
Update on State of the Plant Events, Station Activities and a Summary of Performance Indicators for Refueling Outage 2R18.
Mr. MacIntyre stated he has been in the nuclear energy field for 41 years, having started in the U.S. Navy submarine service and has been employed at DCPP since 1984. Mr. MacIntyre reported he served in the Quality Control organization as a group leader and section supervisor, as Director of Maintenance Training, a general foreman in Mechanical Maintenance, as a reactor operator, shift foreman, shift manager, and as Manager of Electrical Maintenance and Director of Maintenance Services. He reported that in his presentation to the DCISC he would be providing an update on the station’s 4th quarter 2014 performance, the fall 2014 U-2 refueling outage and upcoming key station activities.
Mr. MacIntyre reported both units are now safely operating at 100 percent power with all probabilistic risk assessments (PRAs) per the Safety Monitor program in Green status. Mr. MacIntyre, in response to a question from Consultant Wardell, described Safety Monitor as the program which reviews defense-in-depth key safety features while the plant is online and assesses the impact on safety of performing maintenance on equipment during planned maintenance outage windows.
Mr. MacIntyre reviewed the flashover event which occurred in the 230 kV switchyard on October 31, 2014, when arcing occurred across an insulator due to a buildup of dirt, dust, debris, and sodium chloride from the plant’s marine environment. The 230 kV system provides startup power and its loss due to the flashover resulted in the loss of the 230 kV System standby ability for a period of hours. In response, DCPP conducted a root cause evaluation including input from PG&E Transmission System personnel and designated a project manager with single-point accountability for oversight of DCPP switchyard reliability improvements. The station also developed and implemented a time-based 230 kV washing preventive maintenance strategy and will reconstitute the 500 kV standoff insulator wash program for the insulators located against the Turbine Building for both units. Mr. MacIntyre reported DCPP has developed and implemented a contamination /dust mitigation procedure for activities, including dust mitigation strategies during construction that occurs in the vicinity of high voltage transformers in the 230 kV and 500 kV Switchyards.
Mr. MacIntyre commented concerning workforce management that DCPP’s total current employment consists of 1,421 individuals and that the plant has made 25 new hires during 2014 as follows:
- Emergency Services—4
- Strategic Projects—1
Mr. MacIntyre reported on two NRC Assessments of U-2 during its refueling outage 2R18 as follows:
- 2R18 Occupational Radiation Safety Inspection
- Inspectors evaluated performance using nine different radiation protection inspection procedures.
- Positive feedback received on workers stopping when unsure using human performance tools.
- One non cited violation for a 2013 self-identified inadvertent movement of a radiation barrier. There has been no recurrence of this issue.
- 2R18 Baseline In-service Inspection
- Inspectors noted that the station's Boric Acid Review Team meetings were a positive, and that DCPP had a good boric acid corrosion control program.
- No findings or violations
In response to a request from Consultant Linnen, Mr. MacIntyre stated DCPP leadership is pleased with the results of the Management Observation Program and has expanded the program from its initial scope of using managers and directors to perform observations and coaching for work in the plant to ensure workers are meeting management’s expectations and standards. The program provides feedback to supervisors and, while feedback is not always positive, Mr. MacIntyre stated human performance errors have been reduced and there are plans to involve first line supervisors in making rotational observations for one full day in the field. He remarked this will improve first line supervisors’ ability to engage and to coach workers and to bring information back to their respective crews. Mr. MacIntyre observed there is great benefit from a leadership standpoint to interacting with personnel and to engaging in improvement efforts rather than simply critiquing their performance.
For U-1 Mr. MacIntyre reported DCPP replaced its 500 kV polymer lightning arresters with ceramic arresters to improve station reliability as the ceramic arresters are less likely to experience a catastrophic failure such as experienced by U-2. Power was reduced on U-1 and the unit separated from transmission grid and this work was completed on December 6, 2014. Ceramic arresters have now been installed for both units. The lightening arrester work was scheduled with a planned circulating water tunnel cleaning for U-1which was completed on December 9, 2014. The condenser tube sheet was cleaned, picked and dredged and the entire circulating tunnel between the Intake structure and the Turbine Building was cleaned of biofouling to ensure a high degree of reliability for the condensers throughout the operational cycle.
U-1 experienced a power reduction to 92% to repair a feedwater heater. U-1 reduced power and separated from transmission grid due to a ruptured tube in feedwater heater 1-5A which was plugged. Feedwater heaters 1-5B and 1-5C were also inspected and tubes were preemptively plugged in those heaters also with this work completed on January 3, 2015, with the offline duration for U-1 of 4.6 days. In response to Dr. Lam’s inquiry, Mr. MacIntyre confirmed the feedwater heaters remain well below the plugging limits for maximum numbers of plugged tubes for continued operation.
Mr. MacIntyre reviewed the performance goals and result of the 2R18 refueling outage as follows:
|Recordable & Disabling Injuries||0||0|
|Nuclear Safety Events||0||0|
|Human Event Site Clock Resets||0||0|
|Outage Duration (days)||≤ 33||32|
He reviewed and discussed the 2R18 refueling outage for work on the primary, secondary and electrical systems as follows:
- Steam Generator tube sheet clean and tube integrity inspection
- RCP 2-2 motor overhaul, stator and rotor replacement
- RCP 2-3 seal package replacement
- CFCU inlet damper modification
- Circulating Water Pump Motor overhaul and rebuild
- Turbine extraction steam bellows replacement
- 480 V vital bus G breaker replacement
- 500 kV switchyard relay and breaker upgrades
- Battery and DC panel 2-2 replacement
- Lightning Arrester replacement
Mr. MacIntyre reviewed upcoming key station activities for 2015:
- Emergency Response Organization (ERO) Drill—NRC Performance Indicator (PI) Evaluated—March
- Access Authorization NRC Inspection—April
- OPS Operator NRC Requal Inspection—May
- ISFSI Routine NRC Inspection—June
- 1R19 Refueling Outage—Fall
In response to Consultant Linnen’s inquiry Mr. MacIntyre reported that of the new hires approximately one-third have previous nuclear industry experience with some personnel coming to DCPP from San Onofre Nuclear Generating Station (SONGS). He reported for 2015 there is a hiring plan in place for Maintenance Services with ten new hires in Mechanical Maintenance, six in Instrument & Control, and six new personnel in Electrical Maintenance. Some of the new hires previously worked at DCPP as contract personnel during outages. In response to Dr. Lam’s inquiry, Mr. MacIntyre replied that for the near term he will be focusing most of his efforts on equipment reliability improvement and human performance with additional focus on maintenance fundamentals which is consistent with information received during a recent workshop conducted by the Institute of Nuclear Power Operations (INPO). In response to Dr. Budnitz’ follow up inquiry, Mr. MacIntyre stated that if you have low experience but good human performance tools your performance should be safe but may not be efficient. However, with good maintenance fundamentals and good human performance tools, performance should be both safe and efficient. He observed that maintenance fundamentals come from training and building engagement with the craft workers in the plant and will require involvement by managers and supervisors.
Mr. Harbor requested Mr. Philippe Soenen, Interim Manager of Regulatory Services at DCPP, to make the next presentation to the DCISC. Mr. Harbor stated Mr. Soenen has 12 years’ experience in the nuclear industry and holds a Bachelor of Science degree in Mechanical Engineering.
Review of NRC Performance Indicators, Licensee Event Reports, and NRC Notices of Violation.
Mr. Soenen reported all NRC performance indicators are currently meeting NRC green performance expectations. He reviewed a chart which summarized the NRC Performance Indicators that all nuclear stations report to every quarter. Mr. Soenen stated that DCPP continues to meet all NRC performance indicator thresholds and sets more rigorous thresholds for the Performance Indicators well below the thresholds set by the NRC and investigates and focuses upon any declining areas of performance, currently including that for Safety System Functional Failures and issues or equipment reliability, before these areas 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. Soenen reported during the period from October 2014 to January 2015 the NRC identified seven violations of low level significance including six non cited violations (NCVs) and one finding, all of which were rated Green, meaning that they have a very low safety significance. He reviewed and discussed these with the Committee including the NRC-identified cross-cutting aspect (C-C).
- NCV (Green)—Failure to Document Degraded Conditions in the Corrective Action Process (C-C Aspect H.11 Challenge the Unknown). This violation was due to two examples of unexpected conditions, the first being associated with the 480 V Bus room ventilation system high temperature alarm, while the second was associated with a register louver being in a closed position. Mr. Soenen reported there was no loss of system function or operability associated with either event. Expectations were reinforced for Operations and Maintenance that all unexpected conditions are to be entered into the Corrective Action Program for future evaluation and trending.
- NCV (Green)—Inadequate Maintenance Procedure Resulted in Improper Configuration of Safety-Related Equipment (C-C Aspect H.7 Documentation). This violation was associated with two examples where proper preplanned maintenance procedures were not implemented. The first was related to the register louver being in a closed position and the second with source range nuclear instrumentation being in a configuration that required operator action to perform its function. Documentation was revised and there was no loss of operability or functionality of the systems.
- Finding (Green)—Failure to Provide Adequate Procedural Guidance Resulting in a Loss of U-1 230 kV Off-site Power (C-C Aspect H.5 Work Management). Mr. Soenen reported this was a self-revealing finding for failure to provide adequate acceptance criteria associated with a contractor’s torqueing of a non safety-related load tap changer. Mr. Soenen and Harbor stated PG&E would need to review and respond to Dr. Budnitz question concerning why a procedure was not in place for this work. In response to Dr. Peterson’s request, Mr. Soenen stated NCVs were issued in accordance with the NRC’s more recent Reactor Oversight Process while findings are issued under the former NRC oversight process.
- NCV (Green)—Inadequate Procedure Results in Unnecessary Main Steam Safety Valve Lift (C-C Aspect H.12 Avoid Complacency). This violation was due to not having procedural guidance that would prevent an unnecessary lifting of an atmospheric dump valve or a main steam safety valve during a rapid shut down. These safety-related valves are designed to lift under certain conditions and procedures have been revised to ensure the valves will not lift during a controlled shut down.
- NCV (Green)—Failure to Document Degraded Emergency Diesel Generator Fuel Injector Nozzles in the Corrective Action Program (C-C Aspect P.1 Identification). This violation resulted from two instances when degraded conditions were not entered into the Corrective Action Program. The first was associated with maintenance on a diesel generator with degraded fuel injectors and the second involved loose bolts found on an electrical panel. Expectations have been reinforced concerning the threshold for entering items into the Corrective Action Program.
- NCV (Green) - Inadequate Technical Specification Surveillance Requirement for Emergency Diesel Generators (C-C Aspect P.3 Resolution). This violation was occasioned due to failure to adjust the parameters of full load testing requirements and undertake an appropriate surveillance testing demonstration for a diesel generator after having revised the generator’s full load test surveillance requirement. In response to and in accordance with Surveillance Requirement 303, all of the diesels were successfully tested at the new, higher values.
- NCV (Green)—Longstanding Uncompensated Nonconforming Condition (C-C Aspect H.14 Conservative Bias). This violation was for failure to take timely corrective action after identification of a potential path for gas intrusion into the Containment Spray System. The system was determined to be operable but non conforming and compensatory measures were not put into place. DCPP reviewed the list of degraded, unanalyzed and non conforming conditions and reprioritized the list based upon safety significance of each item and the item’s age in order to expedite resolution of these existing conditions.
Mr. Soenen stated that each violation he discussed was determined by the NRC to have a low safety significance but DCPP recognizes that each must be reviewed for any indication of a trend. In response to Dr. Lam’s inquiry, Mr. Soenen reported the NCV related to diesel generator testing also resulted in DCPP initiating a Licensee Event Report (LER) with the NRC. Mr. Harbor reported that in response to the NCV related to potential gas intrusion into the Containment Spray System DCPP has undertaken to review any other items that are considered degraded or non conforming and is reviewing its bridging strategies and compensatory measures and has made this a focus area.
Mr. Soenen briefly summarized and reported the NRC issued the following inspection reports during the October 2014–January 2015 period:
- Integrated Inspection Report (2014-004, 10/27/14)
- Problem Identification and Resolution Inspection Report (2014-007, 10/22/14)
- Focused Baseline Inspection Report (2014-008,12/15/2014)
- Emergency Preparedness Inspection Report (2014-502,12/1/14)
He stated that all NRC performance indicators are meeting NRC Green expectations. Cross-cutting performance is strong, with no cross-cutting themes identified.
Dr. Peterson thanked Mr. Soenen for his presentation. There was no public comment.
XIV Adjourn Evening Meeting
The Chair adjourned the evening meeting of the Committee at 6:50 P.M. and reported the meeting would reconvene at 8:00 A.M. on February 5, 2015.
XV Reconvene for Morning Meeting
The February 5, 2015, morning public meeting of the Diablo Canyon Independent Safety Committee was called to order by its Chair, Dr. Peterson at 8:30 A.M. Dr. Peterson welcomed those persons present in the audience and watching the proceedings on live streaming video. Dr. Peterson requested any of the members who wished to make remarks to do so at this time.
XVI Committee Member Comments
There were no comments by any member at this time.
XVII Public Comments and Communication
The Chair reviewed the protocol for addressing comments to the Committee for matters on and not on the agenda and invited any member of the public present to address the Committee on matters not on the agenda for this public meeting and invited any comments from members of the public who wished to address the Committee to do so now. There was no response to the Chair’s invitation.
XVIII Information Items Before the Committee
Dr. Peterson introduced Mr. Cary Harbor, Director of Compliance, Alliance and Risk at DCPP and asked Mr. Harbor to introduce the next presentation to the Committee. Mr. Harbor introduced Mr. Barry Allen, DCPP Vice President of Nuclear Services. Mr. Allen has more than 30 years’ experience in the nuclear industry and has held leadership positions at several stations at the executive level and holds a Master of Science degree in Civil Engineering.
Update on the 2015 Operating Plan and Performance Goals and Comparison with Accomplishments Under 2014 Operating Plan.
Mr. Allen reported the DCPP Operating Plan is refreshed each year and looks ahead to the next five years. He described it as a roadmap for the station to communicate with its employees, the PG&E Corporation and the public as to where DCPP is at the present time and where it is headed in the future. Mr. Allen stated key activities completed in 2014 include: accreditation of Operations’ training programs; safe completion of refueling outages 1R18 and 2R18 with very good outage performances; a successful NRC and FEMA-evaluated Hostile Action Based Drill with no findings or violations; a Problem Identification and Resolution (PI&R) inspection by the NRC reviewing the Corrective Action Program; and a technical program training self-assessment of the Maintenance, Chemistry, Radiation Protection and Engineering training programs, which are scheduled for accreditation in 2016. Dr. Peterson commented a DCISC fact-finding team observed the Hostile Action Based Drill and he observed there is value to having realistic training for contingent scenarios and this drill served the plant well with training for beyond design basis FLEX-types of response. The drill conducted at DCPP was the first for an NRC Region IV plant and Mr. Allen remarked that feedback from FEMA on the drill indicated local and state agency cooperation and participation was the best FEMA had seen. Dr. Peterson remarked these drills provide an excellent opportunity for local officials to build emergency response skills and they emphasize the importance of flexibility and decision making in a wide range of situations.
Mr. Allen reviewed the elements and use of the “OUR TEAM” concept used with the Operating Plan to align key elements of short term tactical and long term strategic focus items including: “O” outage planning and execution; “U” human performance tools; “R” reinvigorating employee engagement; “T” transferring and training on critical knowledge; “E” enhancement of facilities; “A” achieving a better work-life balance; and “M” making it a mission to maintain a disciplined approach to safe, event-free operations. Dr. Budnitz observed that six of these seven elements focus on safety culture, the exception being enhancement of facilities. Mr. Allen replied DCPP has constructed an off-site Technical Support Center and Operational Support Center which give the plant the capability to enhance safety by locating the Emergency Response Organization (ERO) offsite.
Mr. Allen reviewed and discussed some of the individual components of the OUR TEAM concept.
Outage Planning & Execution: key elements include increasing line ownership of the outage planning and scheduling processes; a continued focus on risk-related work to ensure effective risk recognition, contingency planning and bridging strategy implementation for outage and online work execution. In response to Consultant Wardell’s question, Mr. Allen stated a preference for establishing a baseline outage duration which might be capable of achieving a 25-day outage when no significant plant modifications were scheduled. Mr. Allen stated that in approximately five years the plant is looking to replace the generator stator for U-2 and that from time to time there may be outages during which it is necessary to drain down the RCS lower than usual.
- Use of Human Performance Tools: key elements include increasing leadership presence in the field, observing and interacting with workers; emphasizing behaviors to stop when unsure or to stop when documents don’t work as written, to reinforce a questioning attitude; streamlining the use of performance improvement coordinators and trending processes to ensure high performance. Consultant Linnen observed and Mr. Allen agreed that emphasizing a behavior to stop when unsure requires overcoming significant barriers as workers may see that behavior as unprofessional. Mr. Allen remarked that the effort to reinforce this behavior is not just with individuals working within the plant but extends station-wide.
- Reinvigorating Employee Engagement: key elements include reinforcing a facilitative leadership model and behaviors that focus on tapping the power of participation; using employee teams (such as advisory councils) to identify opportunities and develop plans of action and Mr. Allen reported employees have suggested positive changes including the use of reverse pre job briefings and better strategies to introduce and integrate new employees into the DCPP workforce and that improve performance and foster employee ownership of human performance.
In response to Dr. Lam’s question regarding resources dedicated to each element of the Operating Plan, Mr. Allen stated appropriate resources have been dedicated to each area but not necessarily in equal amounts in terms of funding as certain elements are more capital expenditure intensive than others but each area receives an appropriate budget and time and attention from leadership.
- Transfer Critical Knowledge: key elements include involving the workforce in implementing tools and processes for knowledge management and transfer and leveraging technology such as the use of wiki-type applications and videos to store and access key knowledge, particularly for infrequently performed activities. Mr. Allen remarked DCPP is working to install wireless access throughout the power block. Dr. Budnitz commented that during a fact-finding visit the DCISC representatives accompanied an operator during the operator’s rounds in the Turbine Building and witnessed the application of new technology. In response to Dr. Peterson’s inquiry, Mr. Allen confirmed DCPP is using wireless technology for plant health monitoring, instrumentation, video observations and other uses but he remarked that DCPP is not yet an industry leader in the application of wireless technology but the infrastructure to reach that goal should be in place within one or two years and he commented it is necessary to proceed cautiously and ensure security concerns are addressed. Dr. Peterson observed it is important for leadership to encourage the rapid adoption of the use of wireless technology and tools as more data collection allows earlier and better capabilities for problem identification and higher reliability for equipment and systems. Dr. Peterson observed that plant health monitoring functions do not include the ability to perform plant control functions and the reactor protection systems will remain operated by hardened, very robust systems and retain a capability for manual intervention. Plant health monitoring data gathering does not have the same challenging cyber security issues as plant control functions.
- Enhancing Facilities: key elements include the offsite establishment of the alternate Technical Support Center and Operations Support Center; new facilities for FLEX equipment and the DCPP Fire Station; upgrading the Outage Control Center and the plant’s fitness facilities. In response to Dr. Peterson’s question, Mr. Allen confirmed FLEX equipment and components will be available at different seismically-qualified locations designed to withstand appropriate forces.
- Achieving Work-Life Balance: key elements include involving the workforce to implement continuous improvement initiatives; implementing an evaluation and specific actions to reduce the cumulative effects of existing and new requirements; implementing a long-term strategy to reduce overtime; and facilitating healthy fitness activities and opportunities such as wellness seminars and onsite walking trails. Mr. Allen reported through the DCPP Annual Campaign for the Community employees have raised more than $433,000 pledged to local non profit organizations. In response to Dr. Peterson’s request, Mr. Allen provided the example of addressing the issue of the level of resources that go into a notification or conditional report on an issue which is of very low level significance as directed to reducing a sense of frustration from having to spend a significant amount of time and resources on an issue which is not creating a problem.
- Maintain Event-Free Operations: key elements include improving key controls for protecting vital power equipment; upgrading equipment for better long term reliability of the emergency diesels, electrical distribution and fuel handling systems.
In response to Consultant Wardell’s request, Mr. Allen commented for 2014 the station achieved its goals within the budget established for the Operating Plan and experienced a good year for nuclear safety performance with no loss of shutdown cooling during two refueling outages and met its goals for radiation, environmental and industrial safety. Mr. Allen confirmed that for 2015 the Operating Plan goals will be similar to those for 2014 and be directed toward DCPP achieving top quartile performance in the nuclear industry.
Mr. Harbor introduced Mr. Dean Overland, the Chair of the DCPP Nuclear Safety Culture Monitoring Panel. Mr. Harbor stated that Mr. Overland has more than 20 years’ experience in the nuclear industry with roles in connection with power plant operations and 12 years’ experience with the NRC. Mr. Overland holds a Bachelor of Science Degree in Nuclear Technology and an MBA.
Overview of Nuclear Safety Culture.
In response to a query from Dr. Budnitz, Mr. Overland stated he had several prior roles with the NRC including doing probabilistic risk assessment for research, as well as serving at the NRC Region IV office in Arlington, Texas, and as a senior resident inspector at the Waterford Nuclear Generating Station in Louisiana and at DCPP. Mr. Overland stated he was relatively new in his job as Chair of the Nuclear Safety Culture Monitoring Panel having recently assumed that position which was previously held by Mr. Harbor.
Mr. Overland described nuclear safety culture as being made up of core values and behaviors which result from a collective commitment from leaders and individuals to emphasize safety over competing goals to ensure the protection of people and the environment. He emphasized that it is not just plant leadership, the entire plant needs to participate and practice nuclear safety culture principles. Mr. Overland described and discussed the traits of a healthy nuclear safety culture as follows:
- Individual Commitment to Safety
- Personal Accountability
- Questioning Attitude
- Effective Safety Communication
- Management Commitment to Safety
- Leadership Safety Values and Actions
- Respectful Work Environment
- Management Systems
- Continuous Learning
- Problem Identification and Resolution
- Environment for Raising Concerns
- Work Processes
Mr. Overland reported that the Problem Identification & Review (PI&R) inspection described previously by Mr. Allen includes the NRC’s review of the station’s Safety Conscious Work Environment (SCWE) which is stressed by industry guidance to ensure that individuals feel free and are openly willing to identify and raise issues, questions or concerns, express differing viewpoints or perspectives dealing with nuclear or radiological safety, quality, security, environmental or regulatory compliance and do so without fear of retaliation. Mr. Overland stated that the preferred route for persons to raise issues is through their supervisor, however, individuals can also go to managers, directors, the NRC, or raise their concerns through the plant’s Employee Concerns Program (ECP). Issues identified are addressed promptly, with timely feedback to the initiator. In response to Dr. Peterson’s inquiry about verifying that a chilled environment for raising concerns does not exist Mr. Overland stated that employees can raise concerns anonymously and one measure of the existence of a chilled environment is assessing the number of anonymous concerns and he remarked that the number of anonymous notifications or concerns raised by DCPP employees is low. He remarked some of the concerns raised anonymously may not necessarily be germane to nuclear safety culture or issues and some may be raised anonymously for reasons of expediency.
Mr. Harbor commented the plant also periodically conducts surveys of its employees concerning their perception of nuclear safety culture and also arranges for independent assessments by outside organizations which include interviews, surveys and observations to assess nuclear safety culture. DCPP leaders also spend time in the plant observing activities and seeking feedback from the craft. Dr. Peterson remarked he was skeptical that there were no employees who feel that in some way their concerns have not been adequately addressed and Mr. Harbor confirmed Dr. Peterson’s observation. Mr. Harbor stated DCPP also monitors its contractors in these efforts and he observed that the Corrective Action Program provides visibility for management’s actions in response to notifications or concerns. Mr. Harbor reported DCPP leadership works to employ facilitative leadership behaviors. He confirmed Mr. Overland’s observation that the data obtained from surveys does not demonstrate a decline in a healthy nuclear safety culture. Mr. Overland commented that sometimes employees may disagree with the outcome or resolution of their concerns but that this is not necessarily indicative of a chilled environment relative to nuclear safety culture. Dr. Peterson remarked that having a fair method for adjudicating disagreements, akin to a peer review process in academia, is a critical element to avoid a chilled environment. Mr. Overland agreed and commented that providing feedback to the individuals raising concerns is a key element and attribute of a healthy nuclear safety culture. Mr. Harbor remarked that, similar to the peer review process cited by Dr. Peterson, DCPP also has a Differing Professional Opinion (DPO) program which allows an appropriate level of review for technical issues.
Mr. Overland stated the Nuclear Safety Culture Monitoring Panel (NSCMP) assesses nuclear safety culture using the recommendations of NEI 09-07, “Fostering a Healthy Nuclear Safety Culture,” which places primary responsibility on management to provide an ongoing holistic, objective, transparent and safety-focused process. The process evaluates inputs from:
- Corrective Action Program
- Performance trends
- NRC inspections
- Industry evaluations, audits, and Operating Experience
- Independent and self-assessments
- Employee Concerns Program
The NSCMP monitors these inputs to identify early indications of potential concerns in the work environment that merit additional attention by the organization. Mr. Overland stated the NSCMP is comprised of experienced personnel with diverse backgrounds and its membership is limited to protect the confidentiality of personal information. In response to a question from Consultant Wardell, Mr. Harbor and Mr. Overland agreed to provide data on the current activity levels for both the ECP and the DPO programs during a future fact finding. Mr. Harbor remarked it was rare for DCPP to receive a concern under the DPO Program. Mr. Harbor reported that five years previously there were fairly high numbers of concerns raised through the ECP but since then those numbers have declined at DCPP and are now in line with industry norms.
Mr. Overland reviewed results of the recent efforts to assess safety culture and reported DCPP has undergone a number of NRC inspections that examined nuclear safety culture attributes of its regulatory, correction action, performance improvement, human resources, ECP, security and quality assurance functions. The latest assessment of the data used for evaluation and trend identification concluded in September 2014, by both the NRC through its PI&R inspection as well as recent NSCMP assessments, indicates that DCPP continues to exhibit the traits of a healthy nuclear safety culture. Mr. Overland concluded his presentation by observing that nuclear safety culture is a constantly evolving concept and DCPP continues to learn from, and make improvements to its nuclear safety culture and has a focus area for 2015 on human performance. He closed with a quote from M. Shawn Covey that “an empowered organization is one in which individuals have the knowledge, skill, desire, and opportunity to personally succeed in a way that leads to collective organizational success”. Mr. Overland stated that the responsibility is placed on management to lay the groundwork for nuclear safety culture and to ensure there is a framework in place in which employees can raise concerns in a respectful work environment and the onus is on individuals to demonstrate personal accountability and a commitment to safety.
Dr. Peterson remarked that safety culture places a great deal of emphasis on achieving a high level of performance and reliability during normal operations and he observed that during the accident at Fukushima the plant staff saved that plant and terminated a severe accident in an environment where the plant staff had no previous training in a FLEX-type response and virtually no resources and abysmal leadership due to a lack of preparation and an unwillingness to believe that an accident of the magnitude experienced at Fukushima was possible. Dr. Peterson observed it is important to develop confidence that nuclear safety culture principles and resources will be available so that they may be depended upon if needed to respond to any accident which may go beyond a plant’s design basis. Mr. Overland agreed and stated his belief that nuclear safety culture principles and training, to work together toward a common goal, are germane to any response to an incident such as that described by Dr. Peterson, and when those principles are embraced and internalized they are not necessarily specific to the magnitude of such an event. Consultant Linnen stated his observations of training in the Simulator facility showed DCPP has developed a method and environment where personnel behave in a reasonable fashion when confronted in drills with worst case scenarios and these types of drills reinforce the kinds of attitudes and behaviors that become embedded in any response.
Dr. Peterson remarked that federal regulations explicitly authorize and transfer responsibility for making decisions and to take actions related to safety to the staff at the involved plant and this is quite different from the approach employed in Japan prior to and during the accident at Fukushima. Dr. Budnitz observed that a Japanese cultural model emphasized loyalty to a particular company as a value, however, this did not allow personnel at the individual utilities to communicate effectively with one another and it prevented the implementation of best practices across the Japanese nuclear industry prior to Fukushima. Dr. Budnitz stated that unless a larger interaction is taking place to foster a cultural affinity for learning from all available sources the implementation of nuclear safety culture will not be as effective as it needs to be.
Mr. Overland commented that DCPP has a healthy Operating Experience program to learn from and to incorporate lessons learned from the experiences of other nuclear power plants and the plant performs internal and external self-assessment in the effort and to feed into a healthy nuclear safety culture. In response to Dr. Budnitz’ inquiry Mr. Overland stated he did not see issues at DCPP in incorporating lessons learned from other facilities. Mr. Harbor observed that PG&E after the San Bruno, CA gas line explosion identified safety culture elements associated with that event and has implemented a corporate, three-year program that includes leadership training, observations, and coaching on a peer-to-peer level to improve safety culture throughout the company and that DCPP is a part of that effort and has also been involved in demonstrating safety culture values present in the nuclear industry to the larger PG&E organization. In response to Dr. Peterson’s inquiry Mr. Overland stated that as he was relatively new in his position he would look to the NRC inspection reports to identify best performers in demonstrating nuclear safety cultural attributes within the industry. Mr. Harbor remarked that the Palo Verde Nuclear Generating Station in Arizona is recognized within the industry for doing an excellent job in creating and sustaining a healthy nuclear safety culture. Dr. Lam commented on the small book each DCPP employee carries while onsite which sets forth the principles and conduct to be employed by a nuclear professional and Mr. Overland confirmed it was DCPP’s expectation that all employees will have and employ these principles available to them at all times and act in accordance while at work at DCPP.
Dr. Gene Nelson, a member of the Cuesta College Physical Sciences Department, was recognized. Dr. Nelson stated he received and reviewed a copy of the small book referred to by Dr. Lam and remarked he found much common sense in its contents. Dr. Nelson stated he appreciated the edition year was given on the cover, indicating it is updated on a frequent basis, and that it included blank pages for employees to make notes which he stated increases their involvement with the principles contained therein. Dr. Nelson stated the Onagawa Nuclear Power Plant in Japan experienced the most shaking ever at a nuclear power plant during the March 2011 earthquake which also affected the Tokyo Electric Power Company’s Fukushima Daiichi plant and the Onagawa plant also experienced a taller tsunami than that at Fukushima. However, the Onagawa plant, managed by the Tohoku Electric Power Company, was able to shut down and the plant proved robust enough to provide shelter to the hundreds of individuals from the local area whose homes were destroyed. He remarked that it was his belief that the experience and performance of the Onagawa plant were the result of a focus by that company on nuclear safety culture. Dr. Peterson stated that Mr. Akiyoshi Obonai, one of his earliest students, was now the Deputy General Manager of the Onagawa plant and served in that capacity in March 2011 during the earthquake which devastated the region. Dr. Peterson confirmed Dr. Nelson’s observations and stated the Onagawa plant had a substantially greater design basis for tsunami protection than that at Fukushima Daiichi.
A short break followed.
Mr. Harbor introduced Mr. Jeff Summy, Senior Director of Technical Services for DCPP. Mr. Harbor stated Mr. Summy has more than 30 years of nuclear industry experience and has held roles in leadership in engineering at several power plants. Mr. Summy holds a Bachelor of Science degree in Engineering.
Overview of the Action Plan for High Voltage Flashovers
Mr. Summy began his presentation with the display of a single line diagram of the electrical distribution system for a single DCPP unit. He reported DCPP has three sources of electrical power serving the plant, with the immediately available offsite power being the 230 kV System coming from the Morro Bay switchyard either directly or through the Mesa switchyard to the 230 kV DCPP switchyard. A second source of offsite power, which Mr. Summy described as a delayed off-site source, is supplied by the 500 kV System which feeds DCPP through various offsite switchyards. A delay is involved when DCPP separates from the power grid due to a turbine or reactor trip and the 500 kV switchyard breakers open and in order to supply power back through the 500 kV System, Operations must open the motor-operated disconnects before the breakers can be reenergized. Mr. Summy reported a third source of power is supplied by the three emergency diesel generators (EDGs) serving each DCPP unit. In the event of loss of 230 kV and 500 kV power, or a combination, the EDGs start automatically and supply the safety-related vital buses at the 4 kV level. In response to a question from Dr. Peterson, Mr. Summy stated that, if necessary, the portable generators provided post Fukushima would tie-in at the 4 kV level and could also be tied-in to directly to Buses F, G and H. In response to Dr. Peterson’s inquiry concerning plans to tie-in portable generators in the event of severe damage to the electrical switchgear areas, Mr. Summy stated that this was a complex subject which should be discussed in context of a presentation on DCPP’s post Fukushima emergency planning efforts and Dr. Peterson requested that this topic be identified for future follow up during review of FLEX. Dr. Budnitz observed and Mr. Summy concurred that DCPP has the ability to connect portable generators directly to its vital loads below the bus level. In response to Dr. Lam’s question, Mr. Summy confirmed that load transfers take place automatically and involve very large and specialized sets of equipment.
Mr. Summy described and provided a summary of the recent flashover events involving the 500 kV Main Bank Transformer Yard. He stated that none of these events impacted DCPP’s ability to supply the safety-related buses. In response to a question from Dr. Peterson concerning any influence played by salt deposition in these events or on the potential for degradation or corrosion of spent fuel canisters Mr. Summy responded that salt deposition did play an important role in the events he will describe. Three 500 kV flashover events occurred, each associated with U-2 and each of which caused U-2 to trip offline from 100% power. These events were a capacitance coupled voltage transformer (CCVT) flashover in Oct 2012; a Phase A lightning arrester flashover in July 2013; and a Phase B lightning arrester failure in February 2014
Mr. Summy reported lightning arresters are designed to withstand more than one lightning strike. He stated that upon each event the electrical buses transferred to 230 kV and continued to be supplied with power with no challenge to safety-related equipment. In response to Dr. Peterson’s inquiry, Mr. Summy stated that a turbine trip from a power level greater than 55% results in an automatic reactor trip. The Palo Verde plant in Arizona is one of a few plants with the ability to drop in selected groups of control rods and to open steam bypass valves to avoid a reactor trip in response to a turbine trip. Dr. Lam commented that in recent years the number of reactor trips within the nuclear power industry has significantly decreased and an actual event, while not desired, does provide an opportunity for operators to experience an actual trip. Mr. Summy reported that with each of the three events involving the 500 kV System, U-2 tripped offline and the equipment and Operations personnel responded as designed and there were no consequences as a result of the trips.
Mr. Summy described and reported on two challenges with 230 kV offsite power flashover events which involved the Morro Bay 230 kV Switchyard in June 2013, and the DCPP 230 kV Switchyard in Oct 2014. Mr. Summy reported the October 2014 event followed 190 days without rain which played a role in these events. He provided a schematic graphic showing the location of the 230 kV and 500 kV occurrences. He remarked that the Morro Bay event on the 230 kV System occurred while the plant was on a single feed from Morro Bay due to reducting work taking place on the Mesa Substation lines in preparation for tying in new solar units and all 230 kV power was lost as a result. The occurrence in October 2014 resulted in all six EDGs starting preemptively but the EDGs did not load to the buses as the buses never lost power. Mr. Summy confirmed that the PRA model has improved to incorporate the loss of switchyard access.
Mr. Summy reported in 2008 a main transformer bushing failure root cause corrective action resulted in the replacement of porcelain-style high voltage insulators with polymer-style insulators and in 2011 and 2012 ceramic CCVTs and lightening arresters were replaced with polymer and he noted that previous to this replacement DCPP had no history of any flashover events in the 500 kV System. He observed that the transformer oil-filled bushing failure was a much different failure mechanism than experienced with the CCVT or lightning arresters. An independent review of the CCVT and lightning arrester insulator failures found a common cause in the very heavy buildup of salt and dust, caused by the repeated sequence of morning fog followed by afternoon drying, on the insulator sheds which the polymer devices could not handle and when rain fell the flashovers occurred. Mr. Summy stated that field service conditions at DCPP for this equipment are classified as unusual service conditions by industry standards. He reported the CCVTs have now been removed. The recommendation from the common cause report was to minimize the generation of airborne dust and dirt and continue to monitor and characterize insulator buildup constituents and deposition rates and evaluate the feasibility of returning to porcelain insulated lightning arresters. DCPP now monitors for insulator dust buildup, has a mitigation plan in place for dust and dirt, and the lightning arrester insulators have been replaced with porcelain and the insulators are now greased which absorbs dust and dirt.
Mr. Summy reviewed the common cause for the 230 kV flashover events which included the installed insulators not meeting the manufacturer’s specifications and insufficient margin for DCPP - Morro Bay service conditions. Mr. Summy reported on the actions taken to address the 230 kV flashover events including time-based cleaning and planned replacement in 2015. In response to Consultant Wardell’s inquiry Mr. Summy remarked that the manufacturer may have overstated the capability for the insulator.
Mr. Summy reviewed the Los Padres - DCPP Electric Power Reliability Plan and summarized the plan as a broad plan designed to improve electrical reliability and capacity of DCPP onsite/offsite power down to the 4 kV level. He reported the objective of the plan, which PG&E began formulating in May 2014, is to provide an integrated assessment of and recommendations for improving the reliability of electric power to the DCPP 4 kV buses and represents a joint effort between DCPP and PG&E Electric Operations. The plan was published in October 2014 and encompasses a five-year strategy based on the principles of meeting compliance, safety, reliability, and affordability goals. He provided a map with an overview of the area addressed by the plan which includes, for the 500 kV System, DCPP, the Gates, and the Midway Substations, and for the 230 kV System, the Morro Bay, Mesa and DCPP substations. He provided a schematic which showed the internal configuration of the 230 kV and 500 kV Systems at DCPP. Mr. Summy described the plan highlights as having compiled action items from previous studies, self-assessments, root causes, independent reviews and including improvements to maintenance strategies, bridging strategies, and modifications. He reported there was a total of 244 actions, each with an assigned owner and a forecast completion date. To date, actions have been taken to resolve 186 items and 58 items remain open and in progress. Mr. Summy stated the plan requires periodic meetings to track and update actions and will be updated periodically to adjust for new information. He discussed and reviewed with the DCISC the long-term plan improvements and schedule for completion as follows:
|Improvement||Forecast Completion Date|
|Generator Output Breakers||2018|
|Diesel Generator Margin Improvement||To be determined|
|Relay Upgrades (500 kV, 230 kV and 115kV)||2015–2018|
|Replace RG165 insulators (Morro Bay, Diablo, Mesa)||2015–2016|
|Diablo 230 kV SVC||2018|
|Diablo 230 kV BAAH GIS||2018|
|Replace Diablo 230 kV circuit switchers||2018|
|Second 230 kV interconnection line & breaker to DCPP||To be determined|
|Morro Bay 230 kV BAAH GIS||2018|
|Morro Bay 115kV BAAH GIS||2016|
|Morro Bay 230/115kV Bank #2||2018|
|Midway—Andrew 230 kV line||2019+|
Mr. Summy reported that for longer-term plant modifications, bridging strategies have been developed as safeguards until the plan can be fully implemented. He remarked that the population of the Los Padres area is growing and the load on the 230 kV System has increased accordingly and as the load increases it is harder to maintain voltage on the system and this is being addressed by installing a static VAR compensator for the 230 kV System. In response to Dr. Lam’s inquiry, Mr. Summy confirmed the above schedule was not dictated by budget concerns.
Mr. Summy summarized the DCPP Flashover Prevention Plan as having a focus on electric power reliability in 2015 and he remarked definite actions are in progress to prevent future flashover events. He described these actions as an integrated, robust plan developed for the broader electrical system with many of the actions having been completed and bridging strategies being implemented until longer term improvement items are completed. Mr. Summy reported that five persons from the Chubu Electric Power Company’s Hamaoka nuclear plant visited DCPP to review and exchange information concerning seismic and tsunami related issues. Dr. Budnitz observed that there was considerable widespread destruction of the electric power grid in Japan following the March 2011 earthquake and a process is in place to upgrade the robustness and reliability of the grid. Dr. Budnitz remarked that during fact-finding the DCISC received information on the population and industrial growth of the local area which was affecting the 230 kV margin and Mr. Summy confirmed that a tie-in to the upgraded Andrews Substation was part of the plan to address that situation by providing another 230 kV feed but this requires obtaining permits and rights-of-way and he confirmed that this is part of PG&E’s plans for serving the area. Dr. Budnitz observed that the design by PG&E was intended to address the problem over a 20-year period and to deal with both voltage sag and frequency sag during peak usage periods. Mr. Summy confirmed Dr. Budnitz’ observation and stated that under design basis conditions if DCPP transfers two units worth of vital loads to the 230 kV System, that transfer under certain conditions will drag the voltage on the system down and this raises the possibility of an EDG startup which the plant would prefer to avoid. Mr. Summy confirmed that DCPP and PG&E have been working with the California Independent System Operator (ISO) concerning grid studies.
Dr. Gene Nelson, on the faculty of Cuesta College Physical Sciences Department, was recognized following Mr. Summy’s presentation. Dr. Nelson inquired why the June 2013 flashover resulted in an outage of unusually long duration. Mr. Summy replied that due to the unusual alignment of the 230 kV System at that time, with one line out of service for reducting, it was necessary to replace insulators and repair lines in the 230 kV Switchyard which extended the outage duration beyond what it would have been had both 230 kV lines been available.
Ms. Sherry Lewis of MFP was recognized and inquired about the various colored lines and symbols use on the map displayed during Mr. Summy’s presentation. Mr. Summy confirmed the triangles represented substations, while the green lines represented the 230 kV System and the red lines the 500 kV System.
Dr. Peterson thanked Mr. Summy for an excellent presentation and stated that the DCISC would be closely following the flashover issue and has a particular interest in understanding the effects of salt deposition on various plant components.
XIX Adjourn Morning Meeting
The February 5, 2015, morning meeting of the DCISC was adjourned by the Chair at 11:00 A.M.
XX Reconvene For Afternoon Meeting
The February 5, 2015, afternoon public meeting of the Diablo Canyon Independent Safety Committee was called to order by its Chair, Dr. Per Peterson, at 1:00 P.M. Dr. Peterson welcomed those present and inquired if there were any comments from the other members.
XXI Committee Member Comments
Dr. Budnitz stated that he found the two presentations made by PG&E during the morning session to be excellent and informative. Dr. Peterson stated the DCISC recognizes and appreciates the time and effort which PG&E devotes to making its presentations to the Committee.
The Chair invited any members of the pubic present to comment on matters not on the agenda at this time.
XXII Public Comments and Communication
Ms. Sherry Lewis of MFP was recognized. Ms. Lewis directed the attention of the Committee to the written comments by Dr. Sam Blakeslee of December 3, 2014. Ms. Lewis stated there is a significant amount of evidence that PG&E has systematically presented interpretations of seismic and ground motion data gathered over the past few years in such a way so as to indicate that whatever earthquake is likely to happen DCPP is not vulnerable. She stated there were two problems with PG&E’s position. Ms. Lewis stated that DCPP is not in compliance with its license from the NRC which requires it to be built to standards to allow it to continue operating even if the strongest possible earthquake were to occur which she stated is known as the design basis earthquake standard. Furthermore, in the event of an even stronger earthquake the plant’s systems, structures and components must have extra margin and continue to function to prevent the core from melting due to residual heat and that this standard is known as the double design earthquake standard. Ms. Lewis stated that since these standards were established two new faults were discovered. These are the Shoreline and Hosgri Faults and both have now found to be larger than previously thought and capable of joint rupture which would release greater energy than DCPP is designed for. She observed the strongest earthquake is now much greater than the design basis standard and the Hosgri evaluation standard is inadequate to ensure safety. Ms. Lewis stated that PG&E is required to apply for a license amendment to address new information or to clearly explain why it is not required to do so. At present, she stated, PG&E has done neither and therefore it is out of compliance with the operating license for DCPP and the law requires that the plant be shut down until regulations are met but the NRC has allowed PG&E to operate DCPP outside its current licensing basis. Ms. Lewis stated Dr. Blakeslee’s statement also addressed the research PG&E was required to undertake in response to State Assembly Bill 1632 in 2006. She observed it was these studies which brought to light the more hazardous faulting around the site of DCPP but understanding the seismicity of the area is only part of the problem as the way in which vibrations travel from a fault to the plant site and how the plant components react to shaking is also required. Ms. Lewis stated seismicity, ground motion, and site characteristics all contribute to the hazard that must be considered, but as the seismic hazard has grown the ground motion hazards have seemingly decreased so that whatever hazard appears on paper DCPP is still shown to be a safe nuclear power plant. Ms. Lewis characterized this approach as criminal by PG&E and she stated PG&E has been allowed to continue operation of DCPP by reassessing ground motion data to imply that the increasing danger of seismicity has been offset by lesser ground shaking at the plant site. She stated this is done by statistical analyses which average a wide range of data from around the world, the preponderance of which does not fit the local situation at DCPP. Ms. Lewis concluded her remarks by stating the DCISC is charged with ensuring the plant is operated safety and that the regulations are being followed and she stated her opinion that for the most part the DCISC fulfills that charge, but she observed the plant is out of compliance with its current operating basis and much time and effort has gone into making it appear scientifically that all is safe enough but this is managed by sleight of hand as there is very little empirical data about how large an earthquake on a nearby fault or faults would be and how it would affect DCPP. She stated that relying on a belief that the plant will be closed before a big earthquake causes a disaster is not adequate, as safety cannot be built upon a hope and a prayer.
Dr. Peterson thanked Ms. Lewis for her comments.
Dr. Peterson requested Mr. Cary Harbor, Director of Compliance, Alliance and Risk at DCPP to continue with the information presentations.
XXIII Information Items Before the Committee
Mr. Harbor introduced Mr. Jearl Strickland, Director of Nuclear Projects at DCPP, and stated Mr. Strickland has more than 30 years of experience in the industry in various leadership roles and he is a registered professional civil engineer. Mr. Strickland has addressed the DCISC on several previous occasions.
Update on the Independent Spent Fuel Storage Installation and Status of the Condition of the Multi-Purpose Canisters.
Mr. Strickland stated his presentation would cover the permitting and construction history for the DCPP Independent Spent Fuel Storage Installation (ISFSI), the expansion in 2014 of its storage capabilities, current loading plans for 2015 and 2016, and an evaluation of extended storage. Mr. Strickland stated that PG&E in developing the ISFSI had to consider how much fuel would be stored at that facility. The premise was that the ISFSI should be licensed and permitted to accommodate all the fuel discharged during 40 years of plant operational life. This requires storage capacity for 138 casks and a license was issued to the ISFSI by the NRC for a 20-year operational life and the California Coastal Commission issued a permit for the ISFSI to operate as long as necessary.
Mr. Strickland reported that infrastructure was developed for the overall facility including for security, slope stabilization, and cask transfer facilities. As PG&E’s expectation was that a federal repository at Yucca Mountain, Nevada, would be in operation at some point in time the ISFSI was developed in phases and initially only two of the seven foundations were constructed which provided the capability to store 38 casks. With the plans for Yucca Mountain now in abeyance it was determined to complete the ISFSI by constructing the five additional foundations in 2014. Dr. Lam disclosed that during his tenure as an NRC Administrative Judge he sat on the licensing board that approved the installation of the ISFSI for DCPP.
Mr. Strickland displayed an aerial photo of the ISFSI which showed the two foundations and approximately 38 storage casks and the large paved area of the five additional foundations. Mr. Strickland also displayed photos of the completed excavation with mud mat in place and reported that the excavation above the mud mat is approximately 8 feet deep from grade to the surface of the foundation and the ISFSI is located on rock and is anchored to that rock by concrete which directly couples the ISFSI to underlying bedrock which is comprised of the same material as that underneath the power plant. Mr. Strickland discussed the embedment rings which he described as the top portion of very large embedded structures that are able to transmit large seismic loads into the lower levels of the foundation and he confirmed Dr. Peterson’s observation that the design contains considerable conservatism and DCPP is the only nuclear plant which anchors its spent fuel storage casks. Dr. Lam commented that in his previous review of licensing issues it was determined that the anchoring system was not required as the generic casks manufactured by the Holtec firm have demonstrated significant margin against tipping. Mr. Strickland agreed that the Holtec design was robust and he stated DCPP chose to be conservative and received a site-specific license which included the anchorage system.
Mr. Strickland displayed a panoramic view of Pad 3 concrete placement and details of the pad expansion and reported each pad is 68 feet by 105 feet by 8 feet thick. There are 20 embedment structures in each pad, and the pad contains approximately 2,040 cubic Yards of concrete. More than 12,000 cubic yards of rock was excavated to allow for the additional pad placement. The expansion provides the capacity for 40 years of operation. In response to Dr. Budnitz’ inquiry, Mr. Strickland stated each pad cost approximately $2,000,000 and as part of the resolution of prior litigation all costs are funded by the federal Department of Energy and not through PG&E’s rates. In response to Dr. Lam’s question Mr. Strickland stated each cask cost approximately $1,200,000 and loading a single cask adds approximately $250,000 to that cost. Mr. Strickland reported DCPP has changed from using 304 stainless steel for the multi-purpose canisters to 316L grade stainless steel to provide better capability.
Mr. Strickland reviewed current loading plans and stated DCPP presently has 29 HISTORM casks in storage containing 928 used fuel assemblies. He reported nine casks will be loaded in 2015 starting in April and 12 casks will be loaded in 2016. This loading activity will achieve minimum spent fuel pool densities in 2016 to meet NRC spacing requirements.
Mr. Strickland stated DCPP is actively involved with the Electric Power Research Institute (EPRI) in researching the impact of chlorides on stainless steel and has volunteered as a test plant. He remarked that DCPP has multiple zones of coastal influence with the heaviest salt deposition occurring at the Intake structure with a lesser deposition at the 300-foot elevation where the ISFSI is located. Mr. Peterson reported the DCISC received a communication from Ms. Donna Gilmore of the San Onofre Safety group which discusses the potential for stress corrosion cracking of stainless steel storage canisters due to salt deposition under humid conditions and the information Ms. Gilmore provided stated that dust samples had been collected from DCPP along with photos of salt crystals associated with that collection and information on sampling and the rate of chloride deposition. In response to Dr. Peterson’s remarks, Mr. Strickland stated that EPRI collected swabs from the DCPP multi-purpose canisters and, to his knowledge, there were no visible salt deposits whatsoever on those canisters. Mr. Strickland stated that requiring A304L low carbon stainless steel for the canisters should reduce the potential for stress corrosion cracking or chloriding and by subsequently having required Grade 316L stainless steel this potential will be further reduced. Dr. Peterson requested that DCPP review with the DCISC the information developed with EPRI during a future fact-finding so the Committee can better assess the question of the potential impact of salt deposition on canister corrosion and the potential for stress corrosion cracking. Dr. Peterson noted the issue is different from that for structures which are under high levels of stress which can cause the cracks to propagate and in this case the issue would be the impact of corrosion on the integrity of the canisters. Mr. Strickland agreed and stated the potential for inner granular corrosion and for crack propagation and potentially a loss of helium would potentially change the environment within a multi-purpose canister. Dr. Peterson remarked the DCISC also has a significant interest in the question of salt deposition in context of the flashover events and also with the possibility of using saltwater cooling towers in place of once-through cooling. The Members directed that Mr. Strickland be provided with copies of the material provided by Ms. Gilmore.
Dr. Gene Nelson of the Cuesta College Physical Sciences Division was recognized. He requested a description of the thickness of the stainless steel used for the canisters and stated he has discussed this issue with Ms. Gilmore and in his remarks to her stressed that existing stress, chloride and moisture are all required for stress corrosion to propagate in the material used for the canisters. Dr. Peterson replied that while there is not a significant amount of internal pressure within the canisters, there would be residual stress remaining from the cooling of weld material and welded locations would be areas of particular interest in such an inquiry. Mr. Strickland reported that the multi-purpose canister shell is comprised of ½ inch stainless steel and the canister lid is a 9-inch forging, welded in place on top with partial penetration welds of approximately 1 inch in depth into the 9-inch thick lid.
A short break followed.
The Chair requested Mr. Harbor continue with the final informational presentation requested by the DCISC for this meeting. Mr. Harbor introduced Mr. Ryan West, System Engineering Manager for the Instrumentation & Control and Electrical Systems at DCPP. Mr. Harbor stated Mr. West has more than 20 years’ experience in the nuclear industry including leadership roles in the Quality Assurance, Instrumentation & Control, and Engineering organizations with a primary focus on electrical systems and components. Mr. West holds a Bachelor of Science degree in electrical engineering.
Overview of the Action Plan for DCPP Large Station Transformers.
Mr. West reported the principal responsibility of the organization he heads is to monitor performance, trends, and to provide long term planning to ensure the reliability of the instruments, controls, and electrical equipment at DCPP. Mr. West reported his presentation would be an update of actions taken since 2010 to enhance the performance of DCPP’s large power transformers.
Mr. West reported that in 2010 DCPP’s large power transformers were not meeting station performance expectations. During 2008, a failure of a U-2 C-Phase high voltage bushing resulting in the shut down of the unit. In 2002 and again in 2009, U-2 C-Phase experienced a loss of cooling on a replacement transformer. In August 2009 an adverse trend was identified from monitoring of transformer bushings.
Mr. West stated that the actions taken by the plant since 2010 have focused on enhancing the performance and operation of large power transformers. He reported large power transformers provide a means for transferring power between the electric transmission grid and DCPP electrical distribution system and he displayed a schematic diagram showing the seven large power transformers for each unit including three main bank transformers, two auxiliary transformers, two start-up transformers. The connections to the transmission grid are backed up by six onsite diesel generators, three serving each unit. He displayed a photo of a U-2 main bank transformer and described its components including high and low voltage bushings, coolers which he described as functioning like a radiator to remove heat from the transformer internals, pumps and fans. In response to a question from Dr. Peterson, Mr. West reported U-1 uses transformers manufactured by General Electric while U-2 uses Siemens transformers and he confirmed that the transformers can be mixed and matched but at present DCPP has spares for both its GE and Siemen units. The transformers also have a control cabinet and an oil tank housing with a reservoir for additional oil.
Mr. West described and discussed the 2010 Action Plans as follows:
- Industry peer review visit to review equipment condition, performance trends and maintenance practices.
- Replace porcelain bushings with polymer
- Purchase improved thermography camera.
- Install improved online transformer gas in oil analyzers to monitor and trend transformer internal conditions. In response to Dr. Peterson’s inquiry, Mr. West confirmed this data is not collected wirelessly but rather is collected by the system engineer on a monthly basis and there is a local alarm which alerts plant personnel to any adverse trend.
- Life Cycle Management Studies by the original manufacturer to determine based upon the installation, maintenance practices, operational history, materiel condition where each transformer may be within its projected life cycle.
- Single Point Vulnerability Studies recommended during the peer review visit and performed by the original equipment manufacturer.
Mr. West reviewed and discussed actions completed to date including:
- U-2 generator step-up and start-up high voltage porcelain bushings replaced with polymer bushings resulting in less maintenance and increased personnel safety.
- Spare 500 kV/25kv, 230 kV/12 kV and 25kV/12 kV transformers purchased and ready for use with contingency plans and work orders pre-prepared for installation. In responding to questions from Drs. Budnitz and Lam Mr. West confirmed that a lead-time of more than one year might be necessary to procure a new transformer.
- Online gas in oil monitoring system installed on all generator step-up and auxiliary power transformers. In response to Dr. Peterson’s question, Mr. West confirmed that the system engineer manually downloads and gathers trendable data and takes oil samples.
- New thermography camera purchased and in use by DCPP engineering personnel for performance monitoring. Mr. West stated this camera can provide temperature indication of delta T’s between similar components and verifies that the components are actually operating.
- U-1 Generator Step-Up transformer control power single point vulnerabilities addressed by the studies.
Mr. West stated transformer oil coolers have been replaced for generator step-up transformers for both units’ 230 kV startup transformers due to the salt environment near the ocean and resulting corrosion and he described this as a significant improvement on reliability.
Mr. West observed that station large transformer performance since 2010 has not been perfect and there are remaining challenges for large power transformers. U-1 start-up transformer experienced a load tap changer failure in August 2013, with no resulting loss of generation, and load tap changer control relay adverse trend corrective actions are in place to address this performance vulnerability including installing a newly manufactured load tap changer diverter switch, and maintenance practices have been revised.
In concluding his presentation Mr. West stated DCPP’s large power transformers are operating safely and their performance is meeting station expectations. Scheduled actions to maintain and increase large power transformer performance include:
- U-1 Generator Step-up Transformer Cooling Pump upgrade 1R19 (2015).
- U-1 Generator Step-up Transformers High Voltage bushing replacement 1R19 (2015).
- U-1 Startup Transformers High Voltage bushings replacement 1R19 (2015).
In summary Mr. West reported the corrective actions implemented since 2010 have been successful at enhancing the performance of large power transformers. Actions to maintain or further increase the performance of large power transformers have been identified and scheduled to achieve continuous improvement. In response to Dr. Lam’s observation Mr. West confirmed that transformer performance issues are not necessarily specific to nuclear power plants as they can be experienced by any power plant or industrial facility that connects directly to the electric transmission grid. In response to Consultant Wardell’s inquiry, Mr. West stated DCPP expects, and life cycle studies support, that the large power transformers can continue to function at least through 2025 when the current operating licenses for DCPP from the NRC will have expired. He stated the plant will be regularly reviewing the issues with the large power transformers on a frequency of every five years. In response to Dr. Budnitz’ inquiry, Mr. West stated that most of the physical work on the large power transformers is performed by contractors but DCPP retains detailed procedures on that work.
Dr. Peterson thanked Mr. West for an excellent presentation.
Dr. Gene Nelson, who is on the Physical Sciences faculty at Cuesta College was recognized. Dr. Nelson commented the most recent studies on the proposal to use saltwater cooling towers at DCPP would increase the salt drift from 1,700 pounds to 1.7 million pounds per year. Dr. Nelson stated he provided information on the vulnerability of large power transformers to a so-called “Carrington” geomagnetic event and asked for confirmation that, given DCPP’s location, there is very little to be concerned about regarding such an event. Dr. Peterson stated the NRC has reviewed geomagnetic events and their potential to impact nuclear power plants. He stated the DCISC review indicates the principal concern is that this sort of event could disrupt the power transmission grid for an extended period of time and accordingly DCPP could lose access to offsite power for some considerable period of time and also lose the ability to send power to the grid. Therefore, the inquiry turns in part on having an adequate supply of diesel fuel and this is now being addressed as part of the FLEX efforts. Concerning salt deposition, Dr. Peterson stated that issue requires further study and he confirmed the salt quantities would likely be significantly increased by the use of saltwater cooling towers but where the salt would be deposited has not been determined. Mr. West confirmed that salt impacts transformer performance but the impact from saltwater cooling towers is unknown. DCPP does have a monitoring program for salt contamination in the area of its transformers which validates that their current design is adequate for their present environment. If the environment were to change, there would need to be further design work and monitoring. Mr. West confirmed work is ongoing concerning geomagnetic events and the long term effects are on the transmission system in that resulting ground currents would impact transformers and result in outages. He reported DCPP now has a supply of diesel fuel sufficient for seven days’ operation and that there are first-priority procedures in place to supply a generator to DCPP to reestablish offsite power.
Dr. Peterson observed this was the final informational presentation requested for this public meeting.
XXIV Concluding Remarks & Discussion by Committee Members Of Future DCISC Activities
Dr. Budnitz requested Ms. Zawalick to coordinate, if possible, a fact-finding visit by the DCISC to PG&E’s Geosciences Department in San Francisco on March 30, 2015, in conjunction with the previously scheduled fact-finding visit to the plant on March 31—April 1, 2015, by Dr. Budnitz and Consultant Linnen. Dr. Budnitz reported that PG&E is scheduled to submit its reports to the NRC on the reevaluation of the seismic and external flooding hazards on March 15, 2015. Dr. Peterson stated that concerning further information to obtain and review, the DCISC will follow up on the internal flooding hazard. It was noted that the November 2015 fact-finding visit is now scheduled on November 18#8211;19, 2015, and the July 2015 fact-finding visit is scheduled for June 10–11, 2015. Ms. Zawalick stated she would confirm the dates requested for 2016 fact findings.
The Members reviewed the new tour format and requested that Ms. Zawalick investigate whether it would be possible to have a slightly larger group than the 15 members of the public and five DCISC representatives who toured the plant on February 4, 2015. Dr. Peterson remarked that if 30 persons could be accommodated, the group could be split to have one subgroup view the Simulator facility while the other subgroup cleared security and visited the Turbine Building and viewed the Control Room, with the subgroups then exchanging locations. Ms. Zawalick stated she would coordinate arrangements for the June 2015 tour with Assistant Legal Counsel Rathie concerning the tour for the June 2015 public meeting. Dr. Budnitz observed that the DCISC Members gain insight from their interaction with the members of the public on these tours. In response to Dr. Peterson’s suggestion, Mr. Rathie confirmed that information on the tour is posted on the DCISC website and he agreed to review the manner in which the DCISC advertises the tour to the public.
Ms. Sherry Lewis of MFP was recognized. Ms. Lewis inquired whether the tour format was now different from that used in the past and the Members confirmed that the tour now visits the Turbine Building, a location inside the plant’s protected area and affords an opportunity to observe operations in the Control Room through a small glass window and the Members confirmed the Simulator facility is not located within the protected area.
Dr. Gene Nelson was recognized. Dr. Nelson inquired whether it would be possible to visit the location of the Spent Fuel Pools. Dr. Peterson replied that the Spent Fuel Pools were located within a radiological controlled area and, while DCISC Members and Consultants visit within radiological controlled areas during fact-finding, there is a very extensive process required for personnel to enter those areas which make public tours impractical.
Mr. Rathie reported the next public meeting of the DCISC will be held on June 16–17, 2015, at the Avila Lighthouse Suites in Avila Beach, California.
Dr. Peterson thanked Mr. Rathie, all the PG&E presenters and particularly Ms. Zawalick and Mr. Harbor for their hard work in setting up this public meeting and he thanked the technicians of AGP video who provide audio, video and internet live-streaming for the DCISC’s public meeting. The Chair also thanked the members of the public in attendance and remarked that the participation by members of the public in the meetings of the DCISC is very important. Dr. Peterson also conveyed the thanks of the Committee to CEC Senior Nuclear Policy Advisor Danielle Osborn Mills for her attendance during this public meeting.
XXV Adjournment Of Seventy-ninth Public Meeting
There being no further business, the seventy-ninth public meeting of the Diablo Canyon Independent Safety Committee was then adjourned by its Chair, Dr. Per Peterson, at 2:47 P.M.