CEC Says Diablo Canyon Should Stay Open

Written by Neil Farrell

Neil has been a journalist covering the Estero Bay Area for over 27 years. He’s won numerous journalism awards in several different categories over his career.

March 8, 2023

Not many things can go from pariah to Godsend, but the Diablo Canyon Nuclear Power Plant might be one of them.

The California Energy Commission became the latest government entity to agree that Diablo Canyon should stay open to support the power grid’s reliability. Diablo Canyon is slated to shutdown when its licenses run out for the Units 1 and 2 nuclear reactors in 2024 and 2025 respectively.

But a growing number of agencies have done an about-face and voted or recommended it stay open for 5-10 more years, while the State brings online more renewable energy sources.

“The California Energy Commission (CEC),” reads a news release dated Feb. 28, “approved a staff analysis recommending the state pursue extending operation of Diablo Canyon Power Plant [DCPP] through 2030 to ensure electricity reliability. The determination is based on data showing California risks energy supply shortfalls during extreme weather events driven by climate change.”

Under Senate Bill 846, the CEC was required to “determine the need to extend DCPP’s license to operate beyond its expiration date of 2025.”

Owned by Pacific Gas & Electric, Diablo Canyon produces some 17% of the State’s so-called “zero emissions electricity” and 9% of the State’s total electrical output, according to the CEC.

CEC Vice Chair Siva Gunda said, “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. This includes maintaining Diablo Canyon’s operations to support reliability statewide in the near-term. 

“An extension would allow more time for additional clean energy projects to come online as we work on the long-term transition away from fossil fuels.”

PG&E had announced Diablo Canyon’s closure, ending an effort to have the reactor licenses renewed through the Federal Nuclear Regulatory Commission. That already lengthy process was being fought every step of the way by environmental groups and plant critics, who have always been leery of the plant due mainly to earthquake safety concerns, among others.

Diablo Canyon, which is located on Point Buchon, has several earthquake faults running offshore that critics are concerned could trigger a temblor large enough to damage the plant and endanger the public.

PG&E had been studying the faults as part of the relicensing process but that ended when the company decided to close it down.

But the State Legislature, Gov. Gavin Newsom, and even the Federal Government including President Biden, have had second thoughts with the realization that so-called green energy plants — solar and wind generation —  won’t be completed in time to replace Diablo’s output.

The SB 846 is one of several bills passed in the State Legislature and signed by Gov. Newsom, that call for keeping the plant open for at least a few more years, even allocating a $1 billion forgivable loan to help PG&E pay for keeping it open.

The company has petitioned the NRC to resume the relicensing using the abandoned application but the NRC has said it must start relicensing anew.

Since the Legislature’s actions last year, other agencies have come on board with studies, recommendations and such in support of the new direction the political winds are blowing.

However, critics continue to oppose the plant’s continued operations and there is no guarantee it will stay open, despite the actions of the State agencies. The CEC said the power is needed now more than ever.

“The determination,” the CEC said of its study and board vote, “comes as California is experiencing a substantial shift in conditions affecting the electric grid, which is transitioning to the state’s clean energy future, while confronting the impacts of climate change. 

“This includes extreme heat and wildfires that threaten the grid with growing frequency and intensity.” 

The big heat wave last fall was an eye-opener for the State. 

“On Sept. 6, 2022, the California ISO [Independent System Operator or ISO] reached a new all-time high peak load of 52,061 megawatts (MW) during a record-breaking 10-day heat wave, nearly 2,000 MW higher than the previous record. 

“Updated forecasts show this type of extreme event is increasingly likely to occur because of rising temperatures.”

The CEC staff is doing additional studies including one that will compare costs to keep Diablo Canyon operating versus the alternatives. And, “At the same time, the California Public Utilities Commission [CPUC] is evaluating how extension impacts electricity rates.”

This could all be a moot point if the NRC votes not to accept PG&E’s relicensing application, despite both the Governor and President agreeing it should remain open for now.

And there’s also the issue of continued use of the once through seawater cooling that’s used to cool steam in Diablo Canyon’s reactors. The State Water Resources Control Board, back in 2020, amended its rules on once through cooling (OTC) to extend the deadline to reduce impacts of OTC on marine life by over 90%, in essence switching cooling methods to dry/air cooling or wet cooling. 

The changes moved back the deadlines for compliance at Diablo Canyon to match the expiration dates on the two reactor licenses.

The SWRCB originally had a deadline of 2015 for fossil fuel plants and 2020 for nuclear power plants to greatly reduce or end the use of seawater or freshwater for cooling steam.

Each plant using OTC was given a target date for closure. Of the 19 power plants that used OTC, 10 — including the Morro Bay Power Plant — simply closed rather than pay to revamp the cooling systems.

Some plants, like Moss Landing, which was updated with new technology in the early 2000s, are seeking other options to meet the requirements.

In a study conducted by PG&E, it was reported that Diablo Canyon uses some 2.5 billion gallons a day of seawater for cooling the reactor’s steam loops and “No effective modifications to existing system are available,” reads the study’s fact sheet. 

The report concluded that dry cooling — essentially big fans drawing air over steam pipes — was infeasible due to either space limitations or earthquake safety issues. 

So-called wet cooling was “likely infeasible” due to adverse impacts and permitting.

PG&E pegged the costs for retrofitting the cooling system to get rid of OTC at $4.46 billion.

So while it seems agencies are falling into line regarding extending Diablo Canyon’s life, there are still significant hurdles to overcome, with the federal NRC the final hurdle outside any potential court challenges.

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