From Environmental Working Group
January 5, 2023
PG&E reports nuclear reactor welding leak at Diablo Canyon facility
EWG: Critical questions about coolant system damage go unanswered
SAN FRANCISCO – Pacific Gas & Electric found damage to part of a reactor cooling system at the aging Diablo Canyon nuclear plant in California, but it hasn’t yet answered key questions about the extent of the problem.
PG&E is the owner of the state’s last remaining nuclear power plant, and found the fault with the reactor coolant system during a routine inspection in October. PG&E detailed the damage in a report to the Nuclear Regulatory Commission, or NRC, in December.
The power company says the system had a crack in the welding of the wall of Diablo Canyon’s Unit 2 reactor, which was shut down for refueling. PG&E says the presumed cause was fatigue, which was caused by vibrations at the facility indicating a weld defect. The utility says the damage meant the unit fell short of NRC operating requirements.
PG&E says it repaired the leak, and the public and plant workers were never at risk. But the utility’s filing with the commission raises several questions, including:
- When was the affected weld last inspected?
- When does PG&E believe the crack in the weld formed?
- Why had the weld flaw not been identified?
- What was the size of the leak when it occurred?
“The communities near Diablo Canyon deserve to know the full details of the incident, how it happened, why it wasn’t discovered earlier and how long it took for PG&E to identify the damage to the reactor coolant system,” said Environmental Working Group President and California resident Ken Cook.
“The main reason for shuttering this aging facility is the potential threat it poses to the public – and PG&E’s overall safety record across its vast service area in the state is among the worst of any power company in the country,” Cook said.
Diablo Canyon’s latest problem highlights ongoing concerns about the stability of the facility and shows why EWG and others are pushing to shut the plant down.
Yet state and federal officials are trying to keep the aging facility operating beyond 2025, when it’s slated to shutter under the terms of a settlement carefully negotiated between PG&E, California and environmentalists.
Last September, at the urging of California Gov. Gavin Newsom, the state legislature approved Senate Bill 846, a law that will keep the plant operating for five more years, until 2030. It will also give PG&E a $1.4 billion loan to cover costs during that extra time.
In November, the Biden administration announced it will give PG&E more than $1 billion in federal funding to keep the plant operating past its scheduled 2025 closure date.
PG&E has also petitioned the NRC to fast-track its October 31 request to extend the license of the twin Diablo Canyon reactors. Four environmental organizations, led by San Luis Obispo-based Mothers for Peace, or SLOMFP, have sent letters to the NRC warning it would violate federal law if it accepts the proposal. The other groups that signed the letters are EWG, Friends of the Earth and Committee to Bridge the Gap.
“PG&E cannot have it both ways,” claimed SLOMFP Board President Jane Swanson. “PG&E stopped preparing the reactors for continued operation in 2016 and voided their license renewal. The company has spent the past six years preparing to mothball the reactors and has saved money by not investing in future operations. It is too late to get a license renewal before the plant must shut down.”
The Environmental Working Group (EWG) is a nonprofit, non-partisan organization that empowers people to live healthier lives in a healthier environment. Through research, advocacy, and unique education tools, EWG drives consumer choice and civic action.