Dry cask storage at the San Onofre Nuclear Generating Station
Dry canister storage at the San Onofre Nuclear Generating Station. Courtesy Southern California Edison

Two recent scandals confirm that public safety is not top priority of either the Nuclear Regulatory Commission or Southern California Edison as they lurch forward with a faulty engineering design for removing spent nuclear waste from cooling pools and loading into dry storage at the now shuttered San Onofre Nuclear Generating Station.

In August 2018, a conscience-driven whistle blower exposed how, because of a system design flaw and human error, a 54-ton canister loaded with highly radioactive waste nearly crashed down 18 feet during a procedure to load it into a dry storage silo in the ground. He also detailed a general atmosphere of neglect for public safety by both the NRC and Edison.

In the latest scandal, it was revealed that the approved loading system can’t avoid scratching the thin (5/8-inch) steel-walled canisters as they are lowered into the concrete-reinforced steel silos. According to the advocacy group SanOnofreSafety.org, the NRC admits that scratches are unavoidable and can trigger cracking which can grow through the canister wall, causing uncontrolled radiation leakage. CEO Kris Singh of Holtec, the company that manufactures the cans, acknowledges that even a microscopic crack would release millions of curies of radiation (one curie is enough to kill you).

According to Charles Langley, executive director of PublicWatchdogs.org, salt from the Pacific Ocean will cause the thin-walled metal cans to fail quickly. “Stainless steel does not really rust when it is exposed to salt, it cracks open. Our experts say that even a minor scratch in one of these cans can pave the way to chloride-induced stress corrosion cracking, and we know that all of the cans have been deeply gouged so far.”

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Another concern is that a crack could release the inert helium gas inside the canisters, which works as a fire-suppressant. If water then gets inside, a chemical reaction with any damaged fuel assemblies could cause a hydrogen explosion. Moreover, there is no method for inspecting, repairing or replacing cracked canisters. Despite these concerns, the NRC has given Edison the green light, and canisters continue being loaded into silos with no plan to move them offsite.

While the risks at San Onofre are very different from the 1986 nuclear disaster at Chernobyl, the lesson from Chernobyl is clear: When dealing with radioactive materials, there is no room for design flaws or human errors. Each of San Onofre’s canisters holds the same amount of deadly Cesium-137 that was released during the entire Chernobyl accident, so short-term, money-saving shortcuts that place the public at risk are absolutely unacceptable.

And that’s just one isotope. There are thousands of pounds of plutonium in the 73 canisters that will be stored at the beachfront San Onofre Nuclear Waste Dump, and plutonium is deadly for 250,000 years. Legal documents secured by SanOnofreSafety.org reveal that the canisters are only warranted for 25 years and the silos for 10.

Donna Gilmore of SanOnofreSafety.org is advocating for storage casks with at least 10-inch thick walls instead of the thin-walled canisters in current use. Langley agrees, stating, “The American people deserve thick-walled casks like the ones that are used in well-regulated countries such as Germany.” Both also agree that long-term storage at San Onofre is inherently unsafe because of risk of earthquakes/tsunamis and vulnerability to terrorist attacks.

As of last month, 30 thin-walled canisters with 100,000 pound payloads of deadly nuclear waste had been buried in the silos at San Onofre. The 43 remaining canisters will be loaded in the coming months.

Contact SanOnofreSafety.org or PublicWatchDogs.org to learn more and get involved.

Sarah Mosko is a licensed psychologist, sleep disorders specialist, and freelance environmental writer who grew up in San Diego but currently lives in Orange County.