NRC and Holtec to face off publicly over redesign of spent fuel canisters at San Onofre plant

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As Southern California Edison gears up to resume loading spent nuclear fuel into its “concrete monolith” at San Onofre, the Nuclear Regulatory Commission is expected to publicly spank contractor Holtec International for failures related to a redesign of the waste canisters — a redesign that caught the NRC, and Edison, by surprise.

A rebuke is not enough for critics, however. They say Holtec’s entire dry storage system is a lemon and want its permits revoked.

On Wednesday, Jan. 9, the NRC will hold what’s called “a pre-decisional enforcement conference” with Holtec “to discuss apparent violations of NRC regulations” stemming from the canister redesign. The meeting, in Maryland, will be open to the public and webcast at video.nrc.gov.

In the first of several mishaps last year, Edison was preparing to load a canister with spent fuel in February when it discovered a loose, stainless steel bolt inside, about 4 inches long. An investigation revealed that Holtec had altered the canister design — adding pins to the bottom of the canisters to help gas flow — without permission from the NRC.

Holtec considered the change minor enough to not require NRC scrutiny; the NRC disagrees.

Holtec “failed to establish adequate design control measures for selecting and applying materials, parts, equipment and processes essential to the function of safety-related structures, systems and components,” the NRC said in a November inspection report, citing two apparent violations of its quality assurance regulations.

Holtec also failed to maintain written records of changes to its canister design, “including an evaluation of why the design change could be implemented without applying to the NRC for an amendment to the canister’s Certificate of Compliance.”

At the conference, Holtec will be able to present additional information on why it did what it did.

In a statement Wednesday, Jan. 2, Holtec stressed that the NRC has confirmed the safety of the canisters with the pins, and that the NRC’s issue is with the process by which the design change was made.

Holtec does not, however, agree with the severity level that the NRC assigned these “apparent violations,” prompting its request for the public meeting, said Joy Russell, Holtec’s senior vice president of business development and communications, in a prepared statement.

Edison, for its part, did a “thorough analysis validated by an independent third-party engineering firm” and is confident that the pin-design canisters can safely store waste, spokesman John Dobken said.

Four pin-design canisters were loaded, and preloading inspections verified that shims in each of them was in the proper position, he said. The other canisters at San Onofre use a non-pin design.

Loading San Onofre’s highly radioactive waste into dry storage — which experts say is far safer than the spent fuel pools where most waste still resides — was halted in August, after a 50-ton canister got stuck on a shield ring near the top of the 18-foot vault where it was to be entombed. The slings supporting the canister’s massive weight went slack, and it hung there, unsupported, for close to an hour, in danger of dropping.

Edison has been refining new procedures, training and technology to ensure that such errors don’t occur again, and is finalizing a schedule with the NRC to resume loading soon, Dobken said.

Critic Donna Gilmore of SanOnofreSafety.org said that’s what getting lost is the potential safety consequences of the pin design — a failure of the pins that could restrict airflow and “present a challenge to the integrity” of the canisters, perhaps even resulting in a radioactive release.

“(T)he canisters loaded with super-hot spent fuel with the defective basket shims cannot be replaced,” she said. “The NRC will likely give them a pass, putting us all at risk for exploding canisters and major radioactive releases.”