Nature Study: Long-term plutonium dose assessment needed after Fukushima — Concerns about Americium-241 also — Deposition south of plant, not only northwest

Published: March 8th, 2012 at 8:22 pm ET


Title: Isotopic evidence of plutonium release into the environment from the Fukushima DNPP accident
Source: Nature Publishing Group
Author: Jian Zheng, Keiko Tagami, Yoshito Watanabe, Shigeo Uchida, Tatsuo Aono, Nobuyoshi Ishii, Satoshi Yoshida, Yoshihisa Kubota, Shoichi Fuma & Sadao Ihara
Date: 08 March 2012

Isotopic evidence of plutonium release into the environment from the Fukushima DNPP accident

The Fukushima Daiichi nuclear power plant (DNPP) accident caused massive releases of radioactivity into the environment. The released highly volatile fission products, such as 129mTe, 131I, 134Cs, 136Cs and 137Cs were found to be widely distributed in Fukushima and its adjacent prefectures in eastern Japan. However, the release of non-volatile actinides, in particular, Pu isotopes remains uncertain almost one year after the accident. Here we report the isotopic evidence for the release of Pu into the atmosphere and deposition on the ground in northwest and south of the Fukushima DNPP in the 20–30 km zones. The high activity ratio of 241Pu/239+240Pu (> 100) from the Fukushima DNPP accident highlights the need for long-term 241Pu dose assessment, and the ingrowth of 241Am. The results are important for the estimation of reactor damage and have significant implication in the strategy of decontamination. […]

Read the full study here

Published: March 8th, 2012 at 8:22 pm ET


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8 comments to Nature Study: Long-term plutonium dose assessment needed after Fukushima — Concerns about Americium-241 also — Deposition south of plant, not only northwest

  • Kevin Kevin


    A paper out today in the journal Scientific Reports shows evidence that radioactive plutonium spread tens of kilometres from the Fukushima Daiichi nuclear plant. The new work could lead people to believe that there is a health risk, but that is not the case.

    Plutonium is a radioactive element that is made inside nuclear reactors. Unlike some of the other contaminants to come from Fukushima, it is not volatile, and it is much harder for plutonium to escape from a nuclear reactor during a meltdown. That doesn’t mean it can’t happen: when Chernobyl’s Unit 4 reactor exploded in 1984, it released a large quantity of plutonium into the surrounding environment.

    Plutonium can be dangerous. When it decays, it usually releases heavy particles such as electrons and helium nuclei. These particles aren’t particularly dangerous outside the body, but if plutonium is ingested they can cause genetic damage.

    The new paper shows that minute quantities of plutonium from Fukushima have spread far from the plant. In samples taken to the northwest and in the J-Village, where workers live, the authors found trace amounts of plutonium in the surface soil (see map). Looking at the ratio of plutonium-241 to plutonium-239, they were able to conclude that the plutonium came from Fukushima rather than other sources, such as old nuclear-weapon tests.

    The additional exposure from inhaling this loose plutonium at the S2 site is around 0.5 millisieverts (mSv) over 50 years.

    This dose — 0.5 mSv over half a century — is five times higher than the government’s current estimate for plutonium exposure from the accident, but it doesn’t mean there’s a health risk. Over the same period, the average person on Earth would receive 120 mSv from natural sources of radiation. Even for those who worry about low-dose radiation, it’s safe to say that this additional plutonium exposure won’t have an impact.

    • Kevin Kevin

      I posted the above as an example of the language Nature used when publishing this stuff. I found it to be remarkable in its attempt to downplay the release of plutonium.

      I also posted this video which is old, but it shows the extent to which the industry will go with these matters.

      • AGreenRoad AGreenRoad

        Now for the rest of the story…. how dangerous could nano particle sized plutonium dust be, after it is spread out around the world through the nuclear explosion at Fukushima reactor #3?

        • Kevin Kevin

          Wow, nice work.

          Just the other day in the long thread were we uncovered the "coverup" all the way to the Presidents Press conference in the rose Garden I asked for some very straight forward laymans langauge about the risk and how it could translayed to people in such away they can understand.

          This amazing compilation you have pulled together here goes a long way toward doing that, now if we can simply translate the langaue the NRC guys were bantering about into something the average joe six pack can comprehend at first blush we can begin the task of unraveling the fairy tale and informing people about what actually did happen and how it may be impacting their lives. (minus of course the details of the status of the reactors and pools /grrrrrr)

          Thanks again for this green road!

    • dka

      Plutonium goes into rivers and sea water, it accumulate in fish, can eating them causes leukemia or kidney failure? it does.
      Plutonium particules from Fukushima have been found in Hawaii.
      It travels very far. 1000km away from Fukushima, Shikoku also identified it from daiichi. There is plutonium particules everywhere in Japan now, moslty Eastern part, but it gets in contact with people and gets in their body in different ways, killing them fast. As some people have died quickly already from eating contaminated fish for example.

      • Kevin Kevin

        Yes DKA,

        I posted the cartoon propaganda as an example of how low these criminals will stoop targeting children, the most vulnerable with this tripe.

  • Small particulate internal exposure may create very low doses in millisieverts, but that is misleading. Even though the sievert is an attempt to accurately account for the different types of radiation and their effects on various body systems, the weighting that is used is primitive at best. The sievert does not accurately express the localized cell damage from internal specks of material like plutonium and cesium. These damaged cells can easily lead to cancers, or in reproductive tissues it can lead to genetic defects passed on to future generations.

  • Bobby1

    The americium that plutonium-241 decays into is more dangerous, because it is water soluble. It gets into everything, like strontium-90 does.