San Onofre Nuclear Power Plant "Near Miss" Incident

I am sharing this statement by Dr. Tom English, of the Samuel Lawrence Foundation:

Some Implications of Basic Physics to the San Onofre “Near Miss” Incident
Dr. Tom English
Samuel Lawrence Foundation https://www.samuellawrencefoundation.org/nuclear-energy

There has been a “near miss” at the San Onofre nuclear power plant. The lives and economic well-being of 8.4 million people within a 50-mile radius of the plant have been put at risk.

As workers were lowering a 49-ton thin-walled 17-foot tall canister packed with high-burnup spent nuclear fuel, the canister got caught on the lip of a guiding ring, “hanging by about a quarter inch,” as OSHA inspector and whistleblower, David Fritch, told a stunned crowd at the end of a community meeting on August 9.

“It’s a bad day. That happened, and you haven’t heard about it, and that’s not right. What we have is a canister that could have fallen 18 feet.”

What would have happened if it had fallen? My colleagues at UCSD and the Samuel Lawrence Foundation have been examining the basic physics of this question. By examining the dropping of the cylinder in free fall, we can estimate the upper energy involved in the initial impact.

 For example, the falling canister could hit the concrete floor of the nuclear waste facility with the explosive energy larger than that of 2 large sticks of dynamite. The resultant damage to the canister could cause a large radiation release.

The damage to concrete/metal structure at the bottom of the hole could ruin the canister’s cooling system. The damage to the concrete would be like that of a fully loaded 18-wheeler truck with a gross weight of 80,000 pounds crashing into reinforced concrete at 23 miles per hour.

These nuclear canisters contain 37 spent fuel assemblies which generate an enormous amount of heat. They are cooled by a simple airduct system, whose pathway could be blocked by the damage caused by the canister’s fall. If this happens, large quantities of water would have to be poured into the hole to cool the reaction and prevent or control a meltdown.

Similarly, as at Japan’s Fukushima nuclear power facility, the enveloping water would instantly become radioactive steam and require the evacuation of millions. Since both the cannister and the surrounding structure could be badly damaged, there may be no available way to pull the damaged canister from the hole and repair it.

The analysis that we have done alerts the NRC and others a more substantial analysis needs to be done of the damage caused by a falling 49-ton nuclear storage cylinder. Continuation of the loading of the fuel is clearly a very dangerous threat to the lives and livelihood of over 8.4 million people.

Software and computer resources are available by which estimates can be made of the impacts of this drop on both the reinforced concrete, and the deformation of the walls on the cylinder.

Our preliminary calculations have already revealed that the combination of the weight and velocity of the cylinder exceeds the Facility (ISFISF) “design criteria for tornado missiles” by a factor of 4. It shall be important to also perform drop tests of the canisters with non-radioactive loads to experimentally determine what will happen to actual canisters.

Dr. Tom English is a former advisor on high-level nuclear waste disposal to President Carter’s Office of Science and Technology Policy, NASA, The Ministry of Industry of the Government of Sweden, and the California Energy Resources Conservation and Development Commission. (760-918-9963)