I have blogged about the San Onofre Generating Station near San Diego before. This plant is owned and was operated by the Southern California Edison (SCE) utility. The plant was shut down in 2013 after replacement steam generators failed. SCE redesigned the replacement generators but were told by the manufacturer that the new designs might not work correctly. SCE told the manufacture to go ahead and build the redesigned generators. SCE also told the U.S. Nuclear Regulatory Commission (NRC) that they had made no changes to the generators and did not need to get approval from the NRC.
As with all shuttered nuclear power plants, there was a question of what to do with all the spent fuel. Some California activists wanted it removed from the site. The operators decided that they would lease land at the Navy’s nearby San Onofre Camp Pendleton for their underground storage facility. They put spent fuel rods into Holtec dry cask containers made of concrete and steel and moved them under ground. Activist fought this decision but lost.
Now the NRC has just issued a report that states that every Holtec dry cask that has been lowered into the ground is damaged. Apparently, there is not enough clearance between the dry casks and the divider shell in the storage hole. The sides of the dry casks already show signs of wear. As a result of such wear, cracks form in the walls of the dry casks. Over time, these cracks will grow and multiply. This could result in the leakage of radioactive materials in casks as well as explosions.
The NRC says that SCE and Holtec have known about this problem since January of 2018 but continued to lower twenty nine dry casks into the storage hole. The NRC has ordered SCE and Holtec to stop loading dry casks into the storage hole until this problem is dealt with. SCE and Holtec say that there is no way to inspect and repair dry casks once they are in the storage hole.
Activists say that the NRC should admit that the Holtec dry casks are based on a faulty design and that the NRC should revoke the licenses of SCE and Holtec to carry out their current dry cask storage plan. They say that the NRC should mandate that all the thin-walled Holtec dry casks should be removed from the storage hole and the spent nuclear fuel in them should be transferred to new thick-walled transportable dry casks. These transportable casks are the only temporary storage system for spent nuclear fuel that can be inspected, maintained, repaired and monitored sufficiently to reduce the risk of explosions and the release of radioactive materials. There are calls for responsible California state agencies to cancel the permits for San Onofre dry cask storage and to withhold Decommissioning Trust Funds until these problems have been solved.
Critics of the work done so far by SCE and Holtec say that the leases for Navy land should be cancelled and that the Navy should bring in their own nuclear experts to deal with what the critics consider to be a national security issue. They say that the thin-walled dry casks being used by SCE and Holtec are a clear and imminent danger to the health and lives of the citizens, and pose potential financial, security and ecological disaster for the state of California, and beyond.
San Onofre Nuclear Generating Station: