The US Nuclear Regulatory Commission (NRC) has approved an exemption request from Pacific Gas & Electric Company (PG&E) to allow continued operation of the Diablo Canyon NPP beyond its current licences. This will allow PG&E to continue operating both units at Diablo Canyon while the company's Licence Renewal Application (LRA) is under review. PG&E intends to submit a new LRA by the end of 2023. The current licences for units 1&2 expire in 2024 and 2025.
NRC's decision supports a decision under California Senate Bill 846 to seek to extend plant operations to support electric reliability during the clean energy transition. Paula Gerfen, PG&E Senior Vice President & Chief Nuclear Officer, said the company, aligned with Senate Bill 846, “will continue on the path to extend our operations beyond 2025 to improve state-wide electric system reliability and reduce greenhouse gas emissions as additional renewable energy and carbon-free resources come online.” The plant’s operation could now be extended by up to 20 years.
NRC’s approval followed a unanimous vote by the California Energy Commission (CEC) to adopt a report finding that extending operations until at least 2030 would be prudent. The analysis found that the state's electricity forecasts for 2024-2030 show potential for reliability deficiencies if Diablo Canyon’s operation is not extended. The report was developed in consultation with the California Independent System Operator and the California Public Utilities Commission (CPUC).
“As California confronts a rapidly changing climate, extraordinary heat events and record energy demand are becoming increasingly ordinary. The state needs to keep all options on the table to protect public health and safety,” said CEC Vice Chair Siva Gunda. “This includes maintaining Diablo Canyon’s operations to support reliability state-wide in the near-term. An extension would allow more time for additional clean energy projects to come on-line as we work on the long-term transition away from fossil fuels.”
The two 1,100 MWe pressurised water reactors at Diablo Canyon began operation in 1985 and 1986, and produce 9% of the state's electricity. PG&E in 2016 proposed closing Diablo Canyon when the two units reached the end of their current operating licences in 2024 and 2025. This was approved by CPUC in 2018. All other nuclear plants in California had already closed. Units 2&3 at Southern California Edison's San Onofre nuclear generating station (SONGS) were prematurely retired in 2013. SONGS 1 operated from 1968 to 1992, and the single-unit Rancho Seco PWR was retired in 1989 following a referendum held in the wake of the Chernobyl accident.
However, in September 2022, California lawmakers voted to extend the operating life of Diablo Canyon by five years, in part by giving plant owner PG&E, a $1.4bn forgivable loan to be repaid with federal funding. In November, the Department of Energy (DOE) announced the conditional selection of the Diablo Canyon to receive the first round of funding from the first round of the $6bn Civil Nuclear Credit (CNC) programme, funded by President Biden’s Bipartisan Infrastructure Law.
Following NRC’s decision, California Governor Gavin Newsom, who had long supported the plant’s continued operation, visited the Diablo Canyon Plant. “As we experienced during the record heat wave last September, climate change-driven extreme events are causing unprecedented stress on our power grid,” he said. “The Diablo Canyon Power Plant is important to support energy reliability as we accelerate progress towards achieving our clean energy and climate goals. I look forward to our continued work with the Biden-Harris Administration and the Legislature to build a reliable and resilient clean electric system.”
Image: Diablo Canyon nuclear power plant (courtesy of PG&E)