28th Annual Report by the Diablo Canyon Independent Safety Committee, July 1, 2017—June 30, 2018
Preface | Executive Summary
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28th Annual Report, Executive Summary, Conclusions and Recommendations

History and Introduction

The Diablo Canyon Independent Safety Committee (DCISC) was established as part of the June 24, 1988, settlement agreement which arose from the rate proceedings for the Diablo Canyon Nuclear Power Plant (DCPP). The DCISC was formed in late 1989 with the appointments of Committee Members and began formal review activities and meetings on January 1, 1990. The original settlement agreement (D.88-12-083) was terminated by the California Public Utilities Commission (CPUC) in its decision to open the state electricity markets to competition on January 1, 1998; however, under the provisions of the Commission’s Decisions 97-05-088, issued on May 21, 1997, and 04-05-055, issued on May 27, 2004, the DCISC will continue to function and fulfill its responsibilities as established under the terms of the 1988 settlement agreement.

The original settlement agreement provided for a three-member Independent Safety Committee for the purpose of “reviewing and assessing the safety of operations of DCPP”. The members serve three-year staggered terms and remain on the DCISC until a new appointment or their reappointment is made. To fill an expired term or a vacancy, the CPUC issues a public notice soliciting applications from interested persons or nominations by others of prospective candidates. Under the revised process in accordance with the restated charter, candidates are selected by the CPUC from the applications plus the incumbent, if willing to serve.

The candidates must be “persons with knowledge, background and experience in the field of nuclear power facilities and nuclear safety issues.” From the list of candidates, the new or returning member is appointed by the Governor of California, the Attorney General of California or the Chairperson of the California Energy Commission (CEC), whichever made the original appointment.

On May 27, 2004, the CPUC issued Decision 04-05-055. In its decision, the CPUC changed the nomination procedures by eliminating from the process the participation of PG&E and the Dean of Engineering at the University of California at Berkeley; modified the requirements for membership on the DCISC to add “knowledge and background in nuclear safety issues” to the “experience in the field of nuclear power facilities” and modified the DCISC’s mandate to require it to undertake public outreach in the community. The Decision concluded the DCISC should retain the discretion to determine how best to accomplish its mandate and that the DCISC shall otherwise continue to exist and to operate and continued funding through cost-of-service rates. To implement this directive the DCISC has continued to expand its public outreach as described in Section 8.0 Public Input and Outreach and continues to consider additional outreach activities.

On January 25, 2007, the CPUC issued Decision 07-01-028. The CPUC had previously adopted new practices and expectations for the DCISC without concurrently restating the Committee’s charter to reflect the changes. In its decision, the CPUC granted the DCISC application for authority to restate its charter including the incorporation into the Restated Charter of several terms, conditions, changes and clarifications necessitated by, and previously authorized by, the CPUC which govern the composition, responsibilities and operations of the Committee. In its decision, the CPUC found the Restated Charter to be in the public’s interest as it reflects the latest authority and obligations of the DCISC. The Committee’s application was unopposed. On June 21, 2016, PG&E announced a Joint Proposal with Friends of the Earth, the Natural Resources Defense Council, Environment California, the International Brotherhood of Electrical Works Local 1245, Coalition of California Utility Employees, and the Alliance for Nuclear Responsibility to retire DCPP at the expiration of the current operating licenses. On August 11, 2016, PG&E filed an Application with the California Public Utilities Commission (CPUC) for approval of the retirement of DCPP, implementation of the Joint Proposal, and for recovery of associated costs through proposed ratemaking.

Under the Joint Proposal, PG&E will continue to operate DCPP at current levels through the current license periods. If the Application is approved by the CPUC, in 2024 PG&E would retire Unit-1, and in 2025 would retire Unit-2. To replace DCPP power, the Joint Proposal provides specific greenhouse gas (GHG)-free procurement requirements beginning in 2018 and continuing through 2031. The Committee will follow developments and activities at DCPP to assure continued nuclear safety during the remaining years of operation, if the joint proposal is adopted.

The Committee Members during this period were as follows:

On October 10, 2007, Robert J. Budnitz, Ph.D. was appointed by California Attorney General Edmund G. Brown Jr. to a term on the Committee expiring June 30, 2010. On April 15, 2010, Attorney General Brown announced the reappointment of Dr. Budnitz to a second three-year term on the Committee commencing July 1, 2010 through June 30, 2013. On June 27, 2013, the CPUC ratified its President’s selection of Dr. Budnitz as one of two candidates for appointment by Attorney General Kamala Harris to serve a three-year term on the DCISC for the period July 1, 2013 to June 30, 2016. During that period, Dr. Budnitz continued to serve as a member of the Committee pending his reappointment or replacement. On July 7, 2016, Attorney General Harris announced the reappointment of Dr. Budnitz to serve a three-year term on the Committee commencing July 1, 2016 through June 30, 2019. Dr. Budnitz served as the DCISC Vice-Chair for this report period, July 1, 2017 through June 30, 2018.

On June 3, 2009, Peter Lam, Ph.D., was appointed by Chair Karen Douglas, J.D., of the California Energy Commission (CEC) to a three-year term on the Committee commencing July 1, 2009 through June 30, 2012. On July 12, 2012, CEC Chair Robert B. Weisenmiller, Ph.D., announced his reappointment of Dr. Lam to a second three-year term on the Committee commencing July 1, 2012 through June 30, 2015. Dr. Lam was reappointed by Dr. Weisenmiller to third three-year term on the Committee commencing July 1, 2015 and ending on June 30, 2018, and subsequently on June 6, 2018, Dr. Weisenmiller announced Dr. Lam’s appointment to a fourth three-year term on the Committee beginning on July 1, 2018 and ending on June 30, 2021. Dr. Lam served as DCISC Chair during this report period, July 1, 2017 through June 30, 2018.

On July 9, 2008, California Governor Arnold Schwarzenegger announced the appointment of Per F. Peterson, Ph.D., PE, to a three-year term on the Committee through June 30, 2011. Prof. Peterson previously served as a Committee member from September 2, 2004, through October 9, 2007. Governor Edmund G. Brown Jr. reappointed Professor Peterson to a term on the Committee commencing July 1, 2011 through June 30, 2014. Professor Peterson was subsequently again reappointed by Governor Brown to a three-year term on the DCISC commencing July 1, 2014 and expiring on June 30, 2017. On October 11, 2017, Governor Brown reappointed Professor Peterson to a three-year term on the Committee commencing July 1, 2017 and expiring June 30, 2020.

Overview of Activities during the Current Period

The DCISC held three public meetings in the vicinity of the Diablo Canyon Power Plant and one public meeting at Berkeley, CA on the following dates:

The Committee regularly performs the following activities:

Technical Consultants & Legal Counsel

The Restated Charter provides the Committee may contract for services including the services of consultants and experts to assist the Committee in its safety review. The DCISC Members are assisted in their important work by technical consultants and legal counsel. For this report period those persons were:

Technical Consultant: Mr. R. Ferman Wardell, a Registered Professional Engineer, holds both Bachelor and Master of Science degrees in Nuclear Engineering from North Carolina State University. He is a 50-year veteran of the nuclear power industry, having been directly involved in design, quality assurance, operation and nuclear safety oversight activities for Duke Energy Corporation’s seven nuclear units. He was formerly Executive Assistant to the Chairman and CEO at Duke Energy. Mr. Wardell has been a Consultant to the DCISC since 1992.

Technical Consultant: Mr. Richard D. McWhorter, Jr., holds a Bachelor of Science in Mechanical Engineering from the United States Naval Academy. He is a 30-year veteran of the nuclear power industry. He served for ten years as a division officer and department head in the Navy’s nuclear submarine program in which he was responsible for the operation of his submarine’s nuclear power plant. Mr. McWhorter then served the U. S. Nuclear Regulatory Commission for ten years first as an Operator Licensing Examiner and then as Senior Resident Inspector at North Anna Power Station. He then was employed for two years as a Systems Engineering Manager for Dominion Virginia Power at North Anna Power Station. For ten years, Mr. McWhorter was employed at Old Dominion Electric Cooperative where he served as Vice President of Operations and Asset Management. Mr. McWhorter has been a Consultant to the DCISC since 2016.

Legal Counsel: Robert R. Wellington, Esq. has been Legal Counsel for the DCISC since its organization in 1989. He is a graduate of Stanford University and the University of California (Hastings) Law School. For over 20 years his practice has been limited to representing several cities, regional wastewater and solid waste districts and other public agencies, including the DCISC. He advises the DCISC with regard to its legal and administrative matters.

Assistant Legal Counsel Robert Rathie, Esq. has been associated with the Committee through his work with the Wellington Law Offices since 1993. He obtained a bachelor’s degree in Social Science and History from Chico State University in 1972 and served for 15 years in the U.S. Merchant Marine as chief purser on board passenger and freight vessels in foreign trade. He received his Juris Doctor degree from Monterey College of Law in 1993. He is a member of the State Bar of California and the Monterey County Bar Association. He assists Mr. Wellington in advising the DCISC with regard to its legal and administrative matters.

The DCISC issues a report for each reporting year, which runs from July 1 to June 30. The report is approved by the Committee Members at the fall public meeting following the end of the reporting period. The first six-month interim report and subsequent twenty-six annual reports covered the periods January 1, 1990 – June 30, 2017.

This twenty-eighth annual report covers the period July 1, 2017—June 30, 2018.

The technical items covered during its public meetings were selected by the DCISC based on the DCISC’s own priorities concerning which technical issues are important to cover. PG&E then responds by providing presentations and experts to participate in the public meetings as requested. The following significant items were reviewed:

Individual Committee Members and consultants reviewed many other items in nine fact-finding visits, inspections and tours at DCPP. The DCISC keeps track of past, current and future items for review in its Open Items List (Section 6.0 and Volume II, Exhibit F).

A DCISC Member visited officials from the California Energy Commission to provide updates on DCISC activities, to discuss agency concerns and comments, and to provide copies of the Committee’s Annual Report.

Public input and questions were received at the public meetings, and by telephone, letter, and e-mail. Members of the public spoke at each of the four DCISC public meetings held during this reporting period. The DCISC has responded to all of their questions and requests during this period.

Overall Conclusion
The DCISC concludes that PG&E operated DCPP safely during the period July 1, 2017—June 30, 2018.

Specific Conclusions

Based on its activities, the DCISC has the following specific conclusions from the major review topics examined during the current reporting period (references to sections of this report are shown in parentheses). Conclusions are based on, but may vary from, information contained in Committee Fact-finding Reports in Exhibit D in Volume 2 of this report.

  1. The DCISC received regular reports on the Nuclear Regulatory Commission (NRC) Performance Indicators, DCPP License Event Reports (LERs) sent to NRC, and NRC Inspection Reports and Enforcement Actions (violations) at each of its Public Meetings as well as copies of these documents throughout the reporting period. The DCISC investigated selected reports at its fact-finding meetings. The number of LERs has decreased significantly and was one during this period. This is the same as the previous period.
  1. The Committee notes that, although the NRC concluded that DCPP operated acceptably, it identified 10 Non-cited Violations of “very low safety significance.” This appears to be an improvement from most previous periods.
  2. The DCISC will continue to review DCPP’s NRC regulatory performance during the next reporting period, paying particular attention to the number and significance of DCPP violations and LERs. (3.6)
  1. A Chemistry technician correctly followed proper Chemistry, Radiation Protection and Human Performance practices in obtaining the pressurized sample. The plant and Chemistry Laboratories appeared orderly and clean. DCPP appears to be appropriately planning for operator staffing, taking into account potential early and normal retirements, resignations, and the possible effects on staffing of the Joint Proposal, which requires plant shutdown in 2025. Plans to observe an Auxiliary Feed Water valve surveillance test were cancelled due to a delay in Maintenance valve preparation. The system components and plant itself appeared to be in good condition. External organizations noted areas for improvement in the Operations Department, and DCPP has moved to implement appropriate corrective actions and include those actions in the Department Excellence Plan. DCPP had not been requested by the California Independent System Operator to implement any procedures for load following. An observation of an operator on data recording rounds in an Emergency Diesel Generator room was positive in that the operator stressed personnel safety as well as good human performance practices. The DCPP Reactivity Management Program was satisfactorily designed and implemented with tight controls and Green (good) performance measures. (4.1.3)
  2. DCPP Maintenance performance is generally satisfactory with initiatives for improvement in selected areas, such as Foreign Material Exclusion and the work order process. Maintenance is beginning to use electronic work orders to streamline the work order process and reduce paper. On-line maintenance is performed effectively with emphasis on managing risk caused by taking equipment out of service while operating. (4.2.3)
  3. The DCPP Engineering Program appeared to be functioning satisfactorily with improvements being targeted in its Excellence Plan. (4.3.3)
  4. Although the DCISC did not review human performance, per se, during this reporting period, it has found DCPP human performance satisfactory in the previous period and did not observe any indicators during this period to indicate otherwise. (4.4.3)
  5. DCPP’s nuclear safety culture appears strong according to its Nuclear Safety Dashboard and from early results of its latest Nuclear Safety Culture Survey. (4.5.3)
  6. DCPP’s Performance Improvement Department, along with its Performance Improvement Coordinators appeared to be an effective asset for plant problem solving and continuous improvement. The Fact-finding Team’s observation of one Corrective Action Review Board meeting was hindered by the fact that a quorum was not present for the meeting. A Corrective Action Program Notification was submitted for the lack of a quorum, and those present at the meeting made a productive use of the time. A second Corrective Action Review Board meeting was performed efficiently and effectively. It was evident that members were prepared, facilitated open and effective discussion, and made clear decisions and action assignments. The DCPP Performance Improvement Department effectively reviews information from the Corrective Action Program to identify adverse trends and initiate appropriate corrective actions. DCPP plans for augmented leadership engagement in Performance Improvement processes appeared appropriate. DCPP routinely collects data from plant equipment, and such data can be manually collected and analyzed on an as needed basis. Possible future uses of advanced or automated equipment data monitoring systems are being reviewed, but no plans currently exist for the installation of such systems. (4.6.3)
  7. Although the DCISC did not review DCPP Emergency Preparedness in the current reporting period (2017–2018), it has concluded in previous reporting periods that the program was satisfactory. (4.7.3)
  8. Probabilistic Risk Assessment is an effective tool in understanding and improving nuclear reactor safety. PG&E has established an effective PRA Program staffed by experienced personnel and utilizes PRA to the full extent in analyzing and operating DCPP safely. (4.8.3)
  9. The 2017 Institute of Nuclear Power Operations (INPO) evaluation of DCPP resulted in a positive assessment along with several Areas for Improvement. DCPP has made plans to address each Area for Improvement. (4.9.3)
  10. The DCPP Radiological Environmental Monitoring Program appeared satisfactory in monitoring and measuring radioactivity in the environment surrounding DCPP. There were no abnormal levels of radioactivity detected. DCPP identified the cause of increased radiation levels in Unit 1 containment and initiated appropriate corrective actions. (4.10.3)
  11. The DCPP Quality Verification Audit Program appeared to be effectively designed and implemented. DCPP’s Software Quality Assurance Program appeared to be comprehensive and designed to assure computer software that could affect the safety of plant operations was developed, maintained, operated, and changed in an appropriately controlled fashion. DCPP Quality Verification’s assessment of Refueling Outage 2R20 was thorough and comprehensive. (4.11.3)
  12. DCPP nuclear fuel has performed well for many years with no leaks or failures. DCPP’s programs for assuring nuclear fuel integrity appear effective. (4.12.3)
  13. During the current period, the DCISC did not review any equipment reliability-related topics, per se, at Fact-finding Meetings, although it did monitor equipment reliability via such measures as forced outage rate, maintenance department performance, etc. The DCISC plans to review equipment reliability during the next reporting period. (4.13.3)
  14. The DCPP Time in the Field/Engagement and Coaching Program, a prescriptive observation program, appeared satisfactory for providing management expectations on human performance and worker safety practices to workers as well as collecting worker input. The DCPP Employee Concerns Program appeared appropriate for receiving and investigating employee concerns in a confidential manner. During 2017, as in past years, there were no significant employee concerns regarding nuclear safety. DCPP successfully accomplished most of the objectives contained in its 2017 Operating Plan. The 2018 Operating Plan contained appropriate focus areas with initiatives and key metrics. (4.14.3)
  15. DCPP has dealt effectively with most equipment and system problems and is focused on improving system health. DCPP’s Plant Health Committee has been improved to focus more on system/component health and meets more frequently, and overall system health has improved. (4.15.3)
  16. The DCPP Steam Generators (SGs) have been performing as expected since their replacement in 2008 and 2009. The most important SG parameter, tube integrity, has been shown to meet all criteria as a result of visual inspection and Eddy Current testing. (4.16.3)
  17. DCPP Performance in Refueling Outages 1R20 and 2R20 was excellent as it met or exceeded most goals. DCPP Quality Verification issued a Finding on the Seismic Induced System Interaction Program and a recommendation for improvement in this area was implemented via procedure revisions. DCISC tours of 2R20 work areas found that the areas appeared to be well maintained and activities were proceeding in an organized manner. (4.17.3)
  18. DCPP has completed implementation of its Cybersecurity Program to meet all current NRC requirements. The program appears to be well designed and implemented, and the program is transitioning to become a permanent, ongoing station program. The DCISC should continue to review the Cybersecurity Program every two to three years. (4.18.3)
  19. DCPP continues to manage its spent fuel satisfactorily in both the Spent Fuel Pool (SFP) and the Independent Spent Fuel Storage Installation (ISFSI). As part of its decommissioning activities, DCPP is investigating accelerated movement of spent fuel from the SFP to the ISFSI. DCPP is continuing to participate in industry initiatives to address the issue of possible corrosion of Multi-Purpose Canisters (MPCs) stored at the Independent Spent Fuel Storage Installation (ISFSI). As a part of ISFSI relicensing, DCPP will need to develop an aging management plan to include MPC inspections. The Cask Transfer Facility located at the ISFSI provides options for more detailed inspections or repairs to an MPC should such be necessary in the future after the SFPs are no longer available. (4.19.3)
  20. The Nuclear Regulatory Commission in its December 17, 2017 final “Staff Assessment (SA) of the FHRR (Flood Hazard Reevaluation Report) concluded that DCPP’s analyses “…are an appropriate representation of the reevaluated tsunami hazard at the Diablo Canyon site.” This concludes NRC’s review of the DCPP flood hazard. (4.20.3)
  21. DCPP is making good progress in repairing and/or replacing its impaired fire doors. At one point, DCPP reported that it had reduced to zero the number of impaired fire doors and the number of roving fire watches used for compensatory actions for impaired fire doors. DCPP has satisfactorily completed its implementation of NFPA-805. (4.21.3)
  22. DCPP FLEX training, training materials, and instruction for Licensed Operators were satisfactory. (4.22.3)
  23. DCPP has successfully implemented its FLEX program of portable equipment and quick-connect connections to mitigate Fukushima-like events, which result in loss of AC power and cooling water. The plant is using FLEX in one application during refueling outages to reduce plant safety risk and is considering other similar applications. The DCISC will review new applications for FLEX equipment when they are identified. FLEX training appeared satisfactory. (4.23.3)
  24. DCPP’s plan for decommissioning continues to be developed. Current activities include establishing the DCPP Decommissioning Engagement Panel, preparing a detailed cost estimate, and obtaining the necessary funds for decommissioning to a green field site. DCPP appears to be appropriately managing Employee Retention Programs, taking into account the requirements of the Joint Proposal as modified by the CPUC. The review process and selection of capital projects to be cancelled with regard to the Joint Proposal 2025 plant shutdown were comprehensive and appeared to be satisfactory in maintaining plant safety and reliability. (4.24.3)


Concerns are items, which, while not necessarily warranting recommendations, need enhanced continuing Committee review and scrutiny, or attention by PG&E. Concerns are monitored more actively and frequently by the Committee than other items. DCISC’s concern follows:

  1. Retention of qualified, experienced personnel necessary to operate DCPP at an appropriate level of safety
  2. Adequate spending on programs and equipment to preserve an appropriate level of nuclear safety



For more information contact:

Diablo Canyon Independent Safety Committee
Office of the Legal Counsel
857 Cass Street, Suite D, Monterey, California 93940
Telephone: in California call 800-439-4688; outside of California call 831-647-1044
Send E-mail to: dcsafety@dcisc.org.