The board’s vote came after hearing testimony from one of the authors of a recent MIT/Stanford University study that made the case for keeping the plant open until 2035.
The study said keeping the plant open until 2035 would save $2.6bn in power system costs. It said said operating the plant for even longer – up to 2045 and beyond – would save $21bn in power system costs and provide other benefits for land and water.
The study said delaying the shutdown could provide multiple benefits by simultaneously helping to stabilise the state’s electric grid, provide desalinated water to supplement the area’s chronic water shortages, and provide carbon-free hydrogen fuel for transportation.
Owner and operator Pacific Gas and Electric Company has scheduled Diablo Canyon for permanent closure in 2025.
The American Nuclear Society said the meeting was attended by PG&E’s director of government relations, Tom Jones, who reiterated his company’s stance on the issue. “We have reviewed the [MIT/Stanford] study and have the utmost respect for the authors and their results,” Mr Jones said.
“The fact of the matter remains that one constraint not analysed in the report was the regulatory environment... We have a marketplace and a regulatory problem for license renewal, which the company endeavoured to pursue from 2009 to 2016. So with that, the state policies have not been realigned that would afford any further operation for Diablo Canyon. We remain on course for decommissioning in 2025 at this time.”
In January 2018, the California Public Utilities Commission approved a proposal for Diablo Canyon’s early retirement submitted by PG&E in concert with organised labour and environmental organisations. The proposal called for the reactors, which began commercial operation in the mid-80s, to be shut down when their current licences expire, in November 2024 for Unit 1 and August 2025 for Unit 2.
PG&E said at the time that the state’s new energy policies would significantly reduce the need for the station’s electricity output.
Earlier this month, nearly 80 scientists, academics and entrepreneurs from a range of disciplines, including former US energy secretary Steven Chu, sent a letter to California governor Gavin Newsom asking him to delay the closure of the two-unit Diablo Canyon, the state’s lone commercial nuclear facility and its top source of green electricity.