Diablo Canyon completes dry storage campaign, seeks ISFSI license renewal
Holtec International announced that it has completed the campaign to transfer Diablo Canyon’s spent nuclear to dry storage ahead of its planned schedule, paving the way for the continued operation of the central California nuclear power plant.
In related news, the Nuclear Regulatory Commission is considering renewing Pacific Gas and Electric’s site-specific license for Diablo Canyon’s independent spent fuel storage installation (ISFSI). If approved, PG&E will be licensed to operate the ISFSI for an additional 40 years.
The campaign: The last of 12 dry storage casks was loaded at Diablo Canyon’s ISFSI in late October, Holtec announced on November 7. This brings the total number of casks stored at the ISFSI to 70—half of the facility’s capacity.
The spent fuel dry storage campaign was coordinated by Holtec, plant owner PG&E, and Diablo Canyon power plant personnel. Holtec announced in June that it had delivered the 12 HI-STORM cask systems to Diablo Canyon in record time and without any safety issues. Holtec’s HI-STORM system comprises a multipurpose canister, a transfer cask, and a storage overpack.
“This project has set a new bar for excellence in execution and partnership between Holtec and PG&E,” said Joy Russell, senior vice president and chief commercial officer of Holtec. “The partnership and coordination to safely manufacture, deliver, and load 384 used fuel assemblies in record time was nothing short of exceptional.”
As required by PG&E, the HI-STORM overpacks are anchored to steel embedment plates in Diablo Canyon’s ISFSI pad. According to Holtec, the anchored casks can withstand any earthquake that has been recorded anywhere on the planet.
IFSI license renewal: As published in the November 12 Federal Register, the NRC has prepared an environmental assessment for the Diablo Canyon ISFSI license renewal and has issued a finding of no significant impact for the action, meaning that an environmental impact statement is not warranted.
Diablo Canyon’s current ISFSI license expired in March of this year, but because PG&E submitted its license renewal application in March 2022, PG&E can continue to operate the ISFSI under the current license under the NRC’s “timely renewal” process. If approved, the renewed license would expire in March 2064.
PG&E’s license allows the company to store up to 4,400 spent fuel assemblies in up to 140 HI-STORM overpacks at the Diablo Canyon ISFSI. According to the NRC, this is sufficient space for all spent fuel that would be generated by the plant’s two units through their current license terms but does not include any fuel that would be generated beyond that.
The current licenses for Diablo Canyon Unit 1 and Unit 2 expire in November 2024 and August 2025, respectively. PG&E submitted its application to renew Diablo Canyon’s operating licenses for an additional 20 years in November 2023. The NRC is currently reviewing the request as a timely renewal.
In its request to renew the ISFSI license, PG&E has proposed no changes in how it handles or stores spent fuel at Diablo Canyon. Approval of the proposed action would not result in any new construction or expansion of the existing ISFSI footprint beyond that previously approved, according to the NRC.
