Tom Kauffman |
There has been a spate of online posts and articles claiming that the failure of the used fuel storage pool at Fukushima Daiichi Unit 4 could result in: “a big explosion, a meltdown in the pool, or a large fire,” that could have widespread health effects all over the world. These claims are false and irresponsible. Consider the facts:
- If for any reason there was a rapid loss of water from the Unit 4 storage pool exposing all of the used fuel to air, the used fuel can’t catch fire or melt because it has been cooled for more than two and-a-half years and no longer generates enough heat to damage itself. The used fuel in the pools at the other three damaged Fukushima units is even older and colder.
- By design, it is physically impossible for the fuel in any commercial reactor in Japan or the U.S. to explode like a nuclear weapon. It’s impossible because the concentration of uranium in the fuel is far too low to cause a nuclear explosion. And there’s nothing that can be done at a site to change that.
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The truth is that the irradiated fuel in the Unit 4 spent fuel pool does pose some hazard and the prudent management of that risk is to remove it from its present location to a safer, more secure location. In other words, do exactly what it being done now at Fukushima.
After the earthquake, tsunami, hydrogen explosion, and water barrage, workers surveyed the Unit 4 reactor building. That survey led to the installation [in 2011] of scaffold-like braces for the spent fuel pool later reinforced by concrete. These steps addressed concerns about the pool’s structural failure, either on its own or aided by aftershocks.
Then workers removed debris from atop the damaged reactor building. This step served two purposes: (1) removing loose radioactive material to make future work less hazardous to workers, and (2) prepare for the next step of removing fuel from the pool.
Last fall, workers removed unirradiated fuel from the Unit 4 spent fuel pool. This was the fuel waiting to be placed into the reactor core upon its restart. This step demonstrated that the overhead crane and supporting infrastructure could handle the loads — and if there was a surprise, its consequences would be minimized with the “test” using unirradiated fuel.
Now, TEPCO [is] removing irradiated fuel from the spent fuel pool.
To date, they have acted with deliberate urgency. Attempting to remove irradiated fuel years ago before shoring up the building and proving the capability of the transfer equipment would have been irresponsible. But TEPCO did not put schedule ahead of safety. They’ve taken time, but not undue time, to understood the problem before applying a solution.
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