Californian regulators have agreed to extending the operations of the Diablo Canyon nuclear power plant for an additional five years, to 2030.

Diablo Canyon (Image: US NRC/PG&E)

The California Public Utilities Commission (CPUC) made its decision on 14 December. The approval is subject to three conditions: the US Nuclear Regulatory Commission (NRC) must continue to authorise the plant to operate; a USD1.4 billion federal loan agreement must not be terminated; and that the PUC does not make a future determination that extended plant operations "are imprudent or unreasonable".

The decision is available on the CPUC's website.

California's lawmakers passed a bill in September 2022 to enable the state's only remaining nuclear power plant to continue in operation until 2030 to ensure energy system reliability and minimise greenhouse gas emissions until additional renewable and zero-carbon energy sources come online. Operator Pacific Gas and Electric Company (PG&E) had previously expected to close the plant at the end of its current operating licences, in 2024 for unit 1 and 2025 for unit 2. PG&E filed a licence renewal application with the NRC in November.

American Nuclear Society President Kenneth Petersen said the CPUC commissioners had made the right choice.

"Keeping California's lights on requires keeping Diablo Canyon online," he said. "Extending plant operations of Diablo Canyon beyond 2025 will safeguard California's clean energy transition by shoring up California's power grid with an always-on and affordable source of dispatchable clean baseload electricity, generated by nuclear energy."

The NRC is reviewing PG&E's licence renewal application.