A nonprofit nuclear power advocacy group in California has called on the Federal Energy Regulatory Commission to step in and review California regulators' decision to approve the retirement of Pacific Gas & Electric's Diablo Canyon nuclear plant in 2025.
Californians for Green Nuclear Power filed a complaint with FERC against several entities Oct. 26 with regards to the upcoming retirement of the 2.24-GW nuclear plant, and asked FERC to launch an investigation into whether shutting down Diablo Canyon violates federal reliability standards (EL21-13).
The group alleges in the complaint that the California Public Utilities Commission, California Independent System Operator, California State Water Resources Control Board and California State Lands Commission violated mandatory reliability standards when they approved "the voluntary plan to retire [Diablo Canyon] in 2025 without first properly analyzing the adverse bulk electric system and adverse bulk natural gas system consequences."
The complaint further alleges that the North American Electric Reliability Corp., which crafts and enforces the reliability standards for the bulk power system, and the Western Electricity Coordinating Council, a regional compliance authority of NERC, "failed to conduct proper oversight or enforce NERC's reliability standards to prevent reliability standards violations caused by removing [Diablo Canyon's] 2,240 MW from the California electric grid."
Reliability challenges
The nonprofit group points to known California-specific hazards, including seismic activity and the state's wildfire safety policies, that it said should have been considered when deciding to retire the nuclear plant as well as underlying reliability issues facing California's electric grid that it asserted would be exacerbated by the premature closure of Diablo Canyon.
A major concern for the group is the state's significant proportion of natural gas-fired generation that is vulnerable to sudden earthquakes and slow aseismic creep that can damage pipelines. According to the complaint, about 60% of California's dispatchable in-state generation comes from natural gas, of which 95% is imported from other states.
Retiring Diablo Canyon would remove the state's largest generator and with it about 10% of in-state generation. Along with the nuclear facility's carbon-free and reliability attributes, its fuel security benefits would also be lost as it operates independently of the state's aging and vulnerable gas transmission and storage system, the complaint said.
The complaint also notes California's high level of dependence on power imported from other states, a contributor to the August 2020 blackouts in California.
Californians for Green Nuclear Power contended that those blackouts were not an isolated incident but a consequence of "much larger systemic reliability challenges that will only be made worse by the voluntary closure of [Diablo Canyon]."
Public safety power shutoff policies, among the state's wildfire safety tools, are expected to present additional reliability challenges as their applicability is likely to expand, the complaint said.
Relief sought
As such, "there are significant reliability benefits to both the bulk electrical and bulk natural gas systems in California associated with the continued safe operation beyond 2025 of PG&E's [Diablo Canyon] as well as the re-commissioning of the San Onofre Nuclear Generating Station that ceased operations in 2012," the group said in the complaint.
Two units at San Onofre were retired after replacement components did not perform as expected and repairs were deemed too costly to be economic. Dismantlement of structures at San Onofre began this year.
The group is seeking "an in-depth reliability analysis focused on how the continued safe operation of [Diablo Canyon] provides the reliability benefits" outlined in its complaint. It also asked FERC to take "action to enforce NERC's reliability standards, as well as review and initiate remediation of the significant reliability concerns raised in this complaint."
PG&E proposed retiring Diablo Canyon in a 2016 application to the CPUC that sought to shut the two-unit facility in conjunction with the expiration of the units' Nuclear Regulatory Commission licenses, on Nov. 24, 2024, for Unit 1 and Aug. 26, 2025, for Unit 2.
The CPUC approved the retirement plan in 2018. Californians for Green Nuclear Power took issue with the ruling, noting that state regulators did not decide on electricity procurement that would be needed to replace the nuclear generation. Rather, the CPUC "left consideration of this critical reliability issue to be considered in the future as part of the CPUC's Integrated Resources Procurement proceeding," the group said.
FERC set a Nov. 16 deadline for comments, protests and motions to intervene in the complaint proceeding.
