OARAI, Ibaraki — A nuclear research facility here has come under scrutiny after workers were exposed to radiation while checking radioactive materials that had remained in storage for 26 years.
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One of the workers exposed to radiation in the accident at the Oarai Research & Development Center of the Japan Atomic Energy Agency (JAEA) on June 6, identified as a male in his 50s, was found with up to 22,000 becquerels of plutonium-239 in his lungs, raising fears he could develop cancer or suffer other health problems.
According to the JAEA, the total level of radioactive materials that entered the man’s blood, bones, organs and other parts of his body was estimated at 360,000 becquerels, based on the amount detected in his lungs.
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Why did the plastic bag rupture? Kazuya Idemitsu, a professor in the Laboratory of Energy Materials Science at Kyushu University, commented, “Over time, the atomic nuclei of uranium, plutonium and other such substances break down, releasing helium nuclei (alpha rays). When stored over a long time, helium gas would build up, and it’s possible that the pressure inside the container rose, resulting in the rupture.”
Sources close to the JAEA also acknowledged this possibility, with one commenting, “It may not have been a good idea to use a polyethylene container, which had a possibility of rupturing, for storage over a long period.”
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