History

Overview of the History and Role of the Diablo Canyon Independent Safety Committee

The concept of an independent safety committee for Diablo Canyon Power Plant arose in context of the opposition by the California Public Utilities Commission's (CPUC) Division of Ratepayer Advocates (now known as the Office of Ratepayer Advocates) and the then California Attorney General (John Van de Kamp) to Pacific Gas &Electric's (PG&E) request for recovery from its ratepayers for the cost of building both Diablo Canyon Nuclear Power Plant (DCPP) units.  Those parties argued that billions of dollars of these costs were unreasonable and to resolve the matter in June 1988 the parties entered into a Settlement Agreement with PG&E providing for "performance based pricing."   Opponents of the Settlement Agreement, such as The Utility Reform Network (TURN) argued that performance based pricing gave PG&E an incentive to maximize energy production and profits which could threaten plant safety.  The CPUC recognized the safety implications of the then established performance based pricing for power produced by DCPP in its approval of Decision 88.12.083 in December 1988 which established the Diablo Canyon Independent Safety Committee (DCISC) to monitor safety at the plant.

Diablo Canyon, with a total capacity of 2,240 Net MW provides 17 percent of the state's zero-carbon electricity and nearly 9 percent of its total  electricity supply. Diablo Canyon employs nearly 1,300 persons.

The Committee was formed in late 1989, began its review activities on January 1, 1990, and conducted its first site visit on April 20, 1990 and first public meeting in San Luis Obispo on May 22, 1990.  The Committee issued an interim report for the period January 1 - June 30, 1990 and has issued an annual report every year since then.  The 21st through the 35th Annual Reports are now available on our website at www.dcisc.org.  The 35th Annual Report was approved at the DCISC's public meeting on October 23, 2025.  These Annual Reports, together with the CPUC Decisions cited herein, serve as source documents for the Committee's formation, continuing role and activities.

The Settlement Agreement provided that:

"An Independent Safety Committee shall be established consisting of three members, one each appointed by the Governor of the State of California, the Attorney General and the Chairperson of the California Energy Commission ("CEC"), respectively, serving staggered three-year terms.  The Committee shall review Diablo Canyon operations for the purpose of assessing the safety of operations and suggesting any recommendations for safe operations.  Neither the Committee nor its members shall have any responsibility or authority for plant operations, and they shall have no authority to direct PG&E personnel. The Committee shall conform in all respects to applicable federal laws, regulations and Nuclear Regulatory Commission ("NRC") policies."

The agreement further provided that the DCISC shall have the right to receive certain operating reports and records of Diablo Canyon, and that the DCISC shall have the right to conduct an annual examination of the Diablo Canyon site and such other supplementary visits to the plant site as it may deem appropriate.  The DCISC is to prepare an annual report and such interim reports as may be appropriate, which shall include any recommendations of the Committee.

As required by the provisions of CPUC decisions and of Assembly Bill 1890 enacted by the California Legislature in 1996, which mandated electric utility rate restructuring and deregulation, PG&E filed an application which proposed a rate-making treatment for Diablo Canyon which would have priced the plant's output at market rates by the end of 2001. On May 21, 1997, the CPUC issued Decision 97-05-088 which, while making the Diablo Canyon settlement adopted in Decision 88-12-083 of no further force and effect, found that the DCISC remains a key element of monitoring the safe operation of Diablo Canyon and continued the DCISC. The Decision ordered that the DCISC remain in existence under the terms and conditions of the settlement agreement (Decision 88-12-083, Appendix C, Attachment A) until further order of the CPUC.

On May 27, 2004, the CPUC issued Decision 04-05-055, the Test Year 2003 General Rate Case, setting the PG&E's revenue requirements for its electric generation operations.  In Decision 04-05-055 the CPUC also: 1) adopted a Stipulation between the DCISC, PG&E, the Office of Ratepayer Advocates (formerly the "DRA"), The Utility Reform Network, the CEC and the San Luis Obispo Mothers for Peace which provided for the DCISC's continued existence and funding through PG&E's cost-of-service rates, at the funding levels established by Decision 97-05-088 and based on the DCISC's funding for calendar year 1996 with a 1.5% annual escalation each year thereafter; 2) changed the nomination procedures for DCISC membership to eliminate from the process the participation of PG&E and the Dean of Engineering at the University of California at Berkeley; 3) modified somewhat the qualification requirements for DCISC membership; and 4) added to the DCISC's mandate a new requirement for public outreach in the local, San Luis Obispo area community.

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 those 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 Diablo Canyon at the expiration of the initial operating licenses from the NRC and to abandon license renewal activities for both units. Unit 1 having commenced commercial operation on May 7, 1985, with an initial license to operate until November 2, 2024, and Unit 2 having commenced commercial operation on March 3, 1986, with an initial license to operate until  August 26, 2025.

On January 10, 2020, a Joint Motion was filed with the CPUC in the 2018 Nuclear Decommissioning Cost Triennial Proceeding (NDCTP)  for Adoption of a Settlement Agreement between PG&E, The Utility Reform Network, the CPUC Public Advocates Office, the Alliance for Nuclear Responsibility, the County of San Luis Obispo, the yak tityu tityu yak tilhini Northern Chumash Cultural Preservation Kinship, and Women's Energy Matters for approval of a Settlement Agreement based upon the Joint Proposal which, if approved, would provide for the Committee's Charter to be amended to extend the Committee's oversight role on nuclear safety matters until all spent nuclear fuel has been transferred from the spent fuel pools to the Independent Spent Fuel Storage Installation (ISFSI). On September 9, 2021 the CPUC approved Decision 21-09-003 approving the Settlement Agreement.

On July 5, 2022, PG&E representatives announced that PG&E would submit an application for funding in an amount of up to $1.1 billion in credits under the federal Civil Nuclear Credit Program, a program to preserve the existing U.S. nuclear reactor fleet, and on November 21, 2022, the Department of Energy announced the conditional selection of Diablo Canyon to receive the first round of Civil Nuclear Credit Program funding.

On September 2, 2022, Governor Newsom signed California Senate Bill 846 (SB 846), codified as Public Resources Code Sections 25233, 25233.2 and 25302.7, Public Utilities Code Sections 712.1 and 712.8, and Water Code Section 13193.5, which allowed for the potential extension of operations at Diablo Canyon beyond the current retirement dates, up to five additional years, under specific conditions as provided by the legislation including approval by the NRC extending the operating licenses for Diablo Canyon. SB846 invalidated the CPUC's approval of PG&E's retirement of Diablo Canyon by 2025.

SB 846 required the CPUC to direct and authorize PG&E to take all actions by no later than December 31, 2023, that would be necessary to operate the Diablo Canyon beyond the current license expiration dates so as to preserve the option of extended operations until October 31, 2029, for Unit 1 and until October 31, 2030, for Unit 2, conditioned on continued authorization from the NRC. In 2023, PG&E submitted its license renewal application to the NRC.

In addition to the DCISC's continuing responsibility under prior CPUC decisions, Public Utilities Code Section 712.1 directs the DCISC to consult with and incorporate into its assessments and recommendations the Independent Peer Review Panel (IPRP) for seismic studies at Diablo Canyon, established by the California Legislature in its adoption of Public Utilities Code Section 712, and to transmit annually its findings and recommendations for improved safety to the Legislature, the Governor, the CPUC, the CEC, the NRC, and PG&E as the licensee, and for PG&E to respond to the DCISC's annual reports and distribute its response to each of the specified governmental entities.

Public Utilities Code Section 712.8 (c)(2)(B) provides the CPUC shall review the reports and recommendations of the DCISC and if the DCISC's reports or recommendations cause the CPUC, in its discretion, to determine that the costs of any upgrades necessary to address seismic safety or issues of deferred maintenance that may have arisen due to the expectation of the plant closing sooner are too high to justify incurring, or if the NRC's conditions of license renewal require expenditures that are too high to justify incurring, the CPUC may issue an order that reestablishes the current expiration dates as the retirement date, or that establish new retirement dates that are earlier than October 31, 2029 for Unit 1 and October 31, 2030 for Unit 2, to the extent allowable under federal law, and shall provide sufficient time for orderly shutdown.

On December 15, 2023, with its approval of D.23-12-036, the CPUC directed and authorized extended operations of Diablo Canyon until October 31, 2029 (Unit 1) and October 31, 2030 (Unit 2) subject to the conditions that: 1) the U.S. Nuclear Regulatory Commission continues to authorize Diablo Canyon operations; 2) the $1.4 billion loan agreement authorized by SB 846 is not terminated; and 3) the CPUC does not make a future determination that Diablo Canyon extended operations are imprudent or unreasonable. The decision also allocates the costs and benefits of extending Diablo Canyon operations among all load-serving entities subject to the CPUC's jurisdiction and made provision for charging, collecting, using, reviewing and authorizing extended operations costs and fees.

On April 2, 2026, after a three-year license renewal process, the NRC renewed the operating licenses for Diablo Canyon for an additional 20 years. Unit 1's operating license will now expire on November 2, 2044, and Unit 2's will expire on August 26, 2045, if California lawmakers agree. A 2022 state law requires the California Legislature to approve any extension of operations at Diablo Canyon that goes beyond 2030. The NRC's review of the application for renewal of the licenses addressed safety and environmental matters and the NRC's consultations with federal, state, local and tribal agencies and public comment. PG&E also gained approvals from the CPUC, the State Lands Commission, and the California Coastal Commission. Both a safety evaluation and a final supplemental environmental impact statement were issues in June 2025. The NRC issued the renewed licenses after receiving documents from PG&E of the required federal certifications under the Coastal Zone Management Act and the Clean Water Act.

The DCISC recognizes its commitment now and in the future to continue to monitor and report on safety of operations at Diablo Canyon. The DCISC will continue to provide information to the public and to the Legislature, the Governor, the California Energy Commission, the California Attorney General, the CPUC and the NRC and to others on developments which may have an impact on safety of operations at Diablo Canyon.