(CN) – Officials with the Nuclear Regulatory Commission asked San Onofre Nuclear Generating Station operator Southern California Edison tough questions Thursday about a 2018 incident involving a canister loaded with spent nuclear fuel that was nearly dropped 18 feet when it was being buried.
The San Onofre Nuclear Generating Station, or SONGS, is located along the coast in San Clemente, California, 60 miles north of downtown San Diego. It closed in 2012 after radioactive reactor coolant leaked from an 11-month-old steam generator.
In 2018, Edison began the decommissioning process and began burying spent nuclear fuel in stainless steel canisters on the beach. But two incidents involving the canisters have raised questions about their safety and are now being reviewed by the commission.
Earlier this month the commission held a public meeting over a faulty waste canister designed by Holtec International which was discovered to have a defect before it was loaded with spent nuclear waste.
On Thursday, the commission considered whether penalties should be imposed for a more serious event at SONGS this past August, when a loaded canister became misaligned on an internal ring which was supposed to center the canister while it was being placed into the storage vault. The loaded canister was lodged on the ring for nearly an hour and could have dropped 18 feet to the bottom of the vault.
Workers eventually were able to hoist it back up, though it sustained some scratches in the process. Edison immediately stopped burying spent nuclear fuel canisters following the incident.
The incident became a lightning rod for nuclear waste advocates who claim the decommissioning process at SONGS has not been handled properly.
More than 400 people registered to watch Thursday’s webinar on the incident which was held live in Arlington, Texas. Last week, Rep. Mike Levin and other members of Congress from Southern California sent a letter to the commission asking to move the meeting near SONGS so members of the public from San Clemente and the surrounding areas could attend in person. The commission declined the request.
Levin has said addressing safety related to the stored spent nuclear fuel at SONGS – located in the 49th Congressional District he serves – is a top priority for him. He plans to discuss SONGS at his first town hall scheduled for Saturday.
At Thursday’s meeting Doug Bauder, Edison’s vice president of decommissioning at SONGS, called the near-drop incident a “serious matter which should not have been allowed to happen.”
He and other officials at SONGS gave a lengthy presentation to commission staff regarding the incident, noting that in the unlikely event the canister dropped it would not have been compromised and there would have been no radiological hazard to the public since the canisters have been shown to withstand being dropped up to 25 feet.
Bauder said new monitoring devices installed following the incident – including a camera installed to monitor the lowering of a loaded canister and alarms – and new training and procedures “proved to be very effective.”
But commission staff seemed skeptical the canister was not compromised at all during the incident and questioned Edison officials at length about the scratches the canister sustained in the process.
Jerry Stephenson, an engineering manager at Edison, told commission staff the scratches were “so minor in the first place” there was no need or feasibility to reduce or mitigate them.
He said the scratches were “the thickness of a couple of sheets of paper, at worst” and that the canisters designed by Holtec could tolerate the scratches without being compromised.
Upon further questioning about the scratches, Bauder pointed out the decommissioning officials would have an inspection program in place by November 2020 which will include monitoring of the scratches.
The commission expects to release its final decision on the matter within 45 days.