Tuesday, October 01, 2013

Setting the Record Straight on the Spent Fuel Pool at Fukushima Daiichi Unit 4

Tom Kauffman
The following is a guest post written by NEI's Tom Kauffman. Though Tom works in NEI's media relations shop. He also spent 23 years working at Three Mile Island, seven of those as a licensed reactor operator. 

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.
    Anti-nuclear extremists are once again trying to scare people by fabricating threats based on false information. Just because they say it over and over and over doesn't make it true.

    6 comments:

    23SecondFracTal said...

    I really dont think you know what you are talking about here. These stories are mostly based on this report in the World Nuclear Industry Status report 2013 (and I reckon they know what they are talking about!!) please read up especially on page 65 about reactor 4. http://www.bibliotecapleyades.net/archivos_pdf/world-nuclear-report-2013.pdf. And otherwise they come from reliable sources who are not perse anti nuclear. Nothing to do with it.

    23SecondFracTal said...

    Please read up on http://www.bibliotecapleyades.net/archivos_pdf/world-nuclear-report-2013.pdf especially page 65 on reactor 4

    Anonymous said...

    To 23SecondFractal, I really don't think you know what you are talking about here. Having read the document you linked to, it is clear the environmental disasters people are panicking over are consequences of hypothetical large-scale damage to the pool and the building, NOT of the removal of the fuel. The document *recommends* removal of the fuel (see last paragraph of section you refer to).

    dean4fukushimahelp said...

    I am with SimplyInfo.org and function as a Fukushima Nuspent fuel poolclear research specialist. My career spanned 35 years in the nuclear industry. There have been many articles on presumed dangers with fuel in the unit 4 spent fuel pool. I have written articles on the pool and the fuel assemblies which is found on the web link. I agree with the statements in this article and in addition, want to dispel factless information being spread the if one fuel assembly touches another in the unit 4 pool, a criticality accident will happen with no control capability. To set the record straight, it takes 12 BWR fuel assemblies configured geometrically in water to reach a condition where criticality is possible. The water is needed to act as a moderator. Our concern in fuel handling is focused on damaged fuel assemblies which may loose fuel pellets what could be fractured and release the fission fragment isotopes into the building and atmosphere

    Leslie Corrice said...

    The WNI Status Report is a compilation of fear-mongering by decidedly biased individuals. None of them have any real nuclear credentials and the name of the group is chosen to make it seem like they are credible. I have filed the report in my "Prophets of Doom" folder. As I posted in my October 11 Fukushima Commentary "Doomsday Prophecies Precede Fukushima’s Spent Fuel Removal" (http://www.hiroshimasyndrome.com/fukushima-commentary.html)...when it's all over and no apocalypse has happened, the doom-sayers will wipe their brows and say "Whew! That was a close one!"

    Joffan said...

    Note that David Lochbaum of UCS - generally a critic of nuclear power - also weighed on the side of rationality on this topic in this NYT article:

    =========
    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.
    =========