SONGS To Pay $116,000 Civil Penalty at San Onofre

SAN CLEMENTE, CA — On August 3, 2018, San Onofre Nuclear Generating Station (SONGS) personnel loaded a stainless steel canister weighing about 50 tons loaded with 37 radioactive spent fuel rods into the storage container. That day, the canister fell nearly 18 feet into a concrete bunker while being transferred from spent fuel pools into dry cask storage.

“What makes this event so serious” according to Troy Pruit, director of Nuclear Safety for the SONGS district, is a cable was not attached to the canister during loading, as required by the NRC license. Rather, photos show it was loosely coiled around the top. To make matters worse, the event was not reported by Southern California Edison (SCE) within 24 hours as required. Instead, it was publicly revealed by a whistle-blower.

What has not been discussed by SONGS or its contractor Holtec International (Holtec), who built the storage system, is the serious issue of gouging damage to the thin-walled stain steel canisters fully-loaded with spent fuel rods as they are loaded into the concrete storage vault. The Nuclear Regulatory Agency (NRC) admits it does not know how deep the gouges are but acknowledges them as a problem. SCE refers to them as “minor scratches.”

Read about the incident here: Wedged Nuclear Waste Canister Raises Alarm At San Onofre

Gasoline storage tanks in California must be double-walled to prevent leakage into the groundwater system. A leak through the first wall enables detection and repair or replacement before release of any gasoline. Shouldn’t we expect the same level of protection with radioactive nuclear waste? But the canisters used to store the spent rods are not only single thin-walled, but they cannot be inspected from the inside or out for cracks or other degradation. Even if they could, the regulators and Holtec both admit the damage would be impossible to fix. Holtecs’s concrete storage vault was built to hold 3.6 million pounds of nuclear waste.

In its December 2017 Management and Disposal of DOE Spent Nuclear Fuel report to Congress, the Nuclear Waste Technical Review Board stated that “[S]pent nuclear fuel and its containment must be retrievable, maintained and monitored in a manner to prevent hydrogen gas explosions in both short and long-term storage and transport. This is not being done.” The thin-walled canisters which are used at most US sites do not meet this requirement.

Compare the thin-wall canisters with the thick casks used outside the US. The cask measures 10" - 19.75" thick, as compared with the ½" to 5/8" thickness of the thin-walled canister used at SONGS. The thick cask can be inspected, both inside and out. It has a continuing monitoring system that detects problems in a manner to prevent leaks. For example, replacement of a metal seal when a pressure change to the lid is detected. The thin-wall canisters have no helium leak detection system.

Damage to the thin-walled canisters as they are downloaded into the storage vault, the system used as SONGS, is a major issue. At the time of the August 3, 2018 near accident, the NRC had approved Holtec’s Final Safety Analysis Report (FSAR) which stated “‘there is no risk of scratching or gouging’ on a canister during downloading operations into the UMAX vault.” After the NRC’s special inspection, SCE revised the FSAR to allow scratches on the canisters during downloading, a revision the NRC determined lacked an “adequate basis to support the change to the FSAR.”

The NRC has now decided to investigate this problem. While doing so, further loading of the canisters sitting steps from the rising Pacific Ocean has been halted.

Related:

• Wedged Nuclear Waste Canister Raises Alarm At San Onofre
• San Onofre Power Station Has New Project Leader For Decommission