Japan Times: Fukushima faces “insurmountable hurdle” if containment vessels are source of lethal radiation in reactor buildings

Published: March 9th, 2012 at 9:31 am ET
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Title: Noda’s definition of ‘safe’ questioned
Source: The Japan Times Online
Date: March 9, 2012

[...] Even before work can start to check the condition of the melted fuel in the reactor cores, Tepco faces the huge obstacle of decontaminating the reactor buildings, experts said.

Radiation levels inside the buildings are extremely high in general but in some areas they are positively lethal, ranging from several hundred millisieverts per hour to more than 1 sievert. [...]

The decontamination process could even turn into an insurmountable hurdle if the containment vessels are confirmed as the source of searing radioactivity, as decontaminating the inside of a containment vessel is at present considered virtually impossible. [...]

Satoru Tanaka, a professor at the University of Tokyo who chairs the Atomic Energy Society of Japan

  • [Tanaka] stressed the importance of accurately mapping the insides of the reactor buildings and identifying precisely where radiation is emanating from
  • “There are large amounts of debris scattered inside the reactor buildings” due to the hydrogen explosions
  • “If radioactive materials are stuck to the debris, decontamination can progress by removing the rubble”
  • “But the high levels of radiation may be coming from the containment vessels themselves,” he warned

Read the report here

Published: March 9th, 2012 at 9:31 am ET
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22 comments

Related Posts

  1. Denki Shimbun: Tepco to search for holes in containment vessels — Trying to determine where radiation is coming from May 17, 2012
  2. NYT: “Cores at three of plant’s reactors melted down, breaching their containment vessels” — Tepco maintains fuel stopped short of breaching containment vessels March 31, 2012
  3. WSJ: Tepco needs to find ways to prevent new nuclear reactions — May happen if fuel not adequately cooled — “Containment vessels are largely empty of water” after leakage September 14, 2011
  4. Mainichi: Melted nuclear fuel seems to be leaking out from reactor buildings November 14, 2011
  5. Kyodo: Groundwater now flowing into Fukushima reactor buildings via cracks in walls — Up to 500 tons a day September 20, 2011

22 comments to Japan Times: Fukushima faces “insurmountable hurdle” if containment vessels are source of lethal radiation in reactor buildings

  • PhilipUpNorth philipupnorth

    It takes a very limited mind to speak of "melted fuel in the reactor cores" at this point. There hasn't been much fuel in any of the reactors for quite a long time now. Nor is it necessary to worry about the containment vessels as the source of the searing radioactivity. If the clouds of steam rising up from the ground between the plants is any indication, the majority of the coriums have left the buildings. Except, of course, for the contents of reactor #3, which has produced the Pu fallout in your home and mine.


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  • bincbom

    They need to locate the coriums. The reactor buildings in all likelihood are largely empty of nuclear materials at this point.


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    • chrisk9

      Sorry to disagree but the reactor buildings are full of radioactive materials and hot spots. Every primary water system,pump, and filter are filled with sediments, fuel fragments and highly radioactive particles that will make any clean up impossible.

      The rule is that any system carrying primary coolant will be contaminated, and this is more extensive in Boiling Water Reactors. And becomes much worse when there is any fuel failure whatsoever. So whatever was loose in the reactor pressure vessel will contaminate the rest of the systems all the way to the turbine. There will be filters and hot spots that will be very close to impossible to ever approach, much less clean up.So this will include the entire auxiliary building which are the rectangular buildings next to the reactor buildings. These buildings contain systems for cleaning up the primary coolant and safety systems some of which were operational during the accident.

      Do not believe any plans for decontamination, it will never happen.


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    • The spent fuel is still there, along with assorted fuel trash that no doubt litters what's left of the buildings quite thickly. I think they're setting us up for a declaration of inability to ever actually locate the corium flows or do an honest in-depth investigation of each plant's untimely demise. Sort of…

      "Well, it melted, and was so radioactive we had to just bulldoze the whole things and bury it forever. Sorry, it was impossible for us to find out exactly what happened."

      Main question going forward is what they'll do about the spent fuel. If they try to remove it there will be extremely significant releases as the degraded and semi-melted assemblies break and spill their contents. If they just bulldoze and bury it along with the coriums, there will be fewer future releases but we'll never know what really happened in the fuel pools either.

      Which would certainly serve the industry's desire to make it all go away without ever having to tell us the truth about what happened. I'm not surprised they're floating this alternative to clean-up and investigation.


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      • chrisk9

        They can bulldoze the reactor buildings and cover up or encapsulate the pressure vessels, but they must do something with the spent fuel pools. There are many multiples of core loads in each spent fuel pool, thousands of bundles. The releases to the environment and localized dose rates would just be too great for them to bulldoze them. So in reality they can not bury anything until the fuel is removed from the fuel pools.

        It will take 3-5 years for that fuel to cool off enough to be moved into dry casks. And that will be a monumental challenge since the buildings and cranes are destroyed. And then in units 3 and 4 there was most likely significant fuel damage and removing anything will be very hard, if not impossible.

        This is why some experts have said this will be 30-40 years to clean up, even then I would like to see the plan. I think the only plan is to enclose everything in a sarcophagus like Chernobyl and then pretend it went away.


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        • crystalwind crystalwind

          Right on, chrisk9. I'm no expert but from what I've read in these posts for the last year: clean up in 40 years? More like 25,000 years. The whole complex is Ex- all over the place. I agree with the sarcophagus plan: That's good for TEPCO. Bulldoze it down, nevermind the flying sparks and the stuff under the ground (if you can't see it, it ain't there, and future deniability), cement it over, make a skateboard park out of it, donate it to Japan with a "So sorry" note, and they'll get a public service commendation. Phew! Problem over!


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      • Kevin Kevin

        Yeah that seems pretty accurate JoyB in terms if issue and perception management. However I am not totally on board with your claim that the "spent fuel is still there." No doubt some fuel remains but I have never seen evidence to suggest "its still there" in its entirety.


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    • Misitu

      Not empty, according to the robot's reported measurements.

      I would tend to be with chrisk9 on this. Added to your list of contaminated areas, Chris, I would mention the harbour area and any other seashore location receiving groundwater seeps (oh and the usual overflow).


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  • James2

    All these headlines are designed to put it into the past, while in reality the fires from the nuke fuel are still burning very brightly – 1 year later.


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  • gottagetoffthegrid

    When TEPCO inserted the camera into the CV of Unit 2 to look around they could have attached a new/fresh/ calibrated radiation sensor, but they didn't. (or they kept it secret).

    however, if you believe the tweet that was posted here on ENENEWS from someone involved in the scoping, the camera was rated for 1000Sv and it was totally fried by the end of the 70 minute exercise. this would mean that the dose rate in the CV was over 850 Sv/hr.

    even if the core in unit 2 has gone china syndrome (well, argintina syndrome in this case) the CV is still at the top of one heck of a hot chiminey.


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  • This guy is in charge of India's nuclear reactors:

    “There is no nuclear accident or incident in Fukushima… It is a well-planned emergency preparedness programme… (that) the nuclear operators of the Tokyo Electric Power Company are carrying out to contain the residual heat after the plants had an automatic shutdown following a major earthquake.”
    http://www.tehelka.com/story_main52.asp?filename=Op170312Denial.asp

    Reminds me of some people I used to go to school with. Except, the last one (a boxer) met with a hard right and a bleeding nose. (Yes, I did get the strap, and enjoyed it).


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  • CaptD CaptD

    RE: The Corium(s), I think one or more of the corium(s) are plunging (in slow motion) downward into the soil below the complex and are being helped along by Gravity (because of their great Mass), Earth Quakes and they are already interacting with the groundwater as it rises and falls due to rainfall and or snow fall in the higher elevations above Fukushima!


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  • CaptD CaptD

    Did anyone serious expect any review Board in Japan to come out and say that ALL land based nuclear reactors are just as vulnerable as the Fukushima Reactors?

    No way that the Japanese Nuclear Industry would approve anything that even "HINTS" at that; so this to me is yet just more Nuclear Baloney (NB) designed to try and calm folks down just before the anniversity of 3/11…

    I think it will have the opposite effect and further convince the Japanese people that their regulators and their utilities are "in bed" with each other and that Utilities Corp. profits are much more important than public health…


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