2000 Fiscal Year Final Research Report Summary
Tritium behavior in the environment and absorption dose
| Project/Area Number |
11308015
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| Research Category |
Grant-in-Aid for Scientific Research (A).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Nuclear fusion studies
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| Research Institution | IBARAKI UNIVERSITY |
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Principal Investigator |
ICHIMASA Yusuke IBARAKI Univ.Faculty of Sci.Prof, 理学部, 教授 (30007760)
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| Co-Investigator(Kenkyū-buntansha) |
ITO Akihiro HIROSHIMA Univ.Res.Inst.Radiat.Biol.Med.Prof., 原爆放射能医学研究所, 教授 (60034633)
MOMOSHIMA Noriyuki KUMAMOTO Univ.Science, Prof., 理学部, 教授 (80128107)
SAITO Masahiro KYOTO UNIV.Res.React.Inst., Prof., 原子炉実験所, 教授 (40027454)
WATANABE Hiromistu HIROSHIMA Univ.Res.Inst.Radiat.Biol.Med.Prof., 原爆放射能医学研究所, 教授 (00034653)
KOMASTU Kenji HIROSHIMA Univ.Res.Inst.Radiat.Biol.Med.Prof., 原爆放射能医学研究所, 教授 (80124577)
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| Project Period (FY) |
1999 – 2000
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| Keywords | Tritium / Environmental tritium / Biological effects of tritium / Dose assessment / Field release experiment |
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| Research Abstract |
1) The radiation absorption dose of tritium in an imaginary accidental release from a nuclear reactor was calculated using UFOTRI code. If tritiated water was released for 1hour at a rate of 1Bq/sec. into the environment from the stack of 100m in high, the absorption doses at the maxim point, 2km of downwind, on the ground were from 8E-16 to 9E-15Sv. These differences of absorption dose values were primarily occured with different temperature and humidity conditions in the environment. Further investigations are now underway.
2) Safety handling methods were examined in the tritium handling laboratories of a nuclear reactor. Room monitoring system was more important for safety protection purpose of workers than stack monitoring. It was suggested that, in case of accident, tritium concentration in room air in a short duration of working time should be estimated 30-40 times higher than that in attack air.
3) Fifty mSv/y of radiation absorption dose is really safe for tritium handling workers? One mSv/y radiation dose is also safe for the public around nuclear facilities? Annual radiation absorption dose in Japanese is 1.5mSv from natural radiations, 2.3mSv from medical radiation, and the world average is 2.4mSv/y. The intake of tritiated water, 6x10E7Bq, gives 1mSv/y. The administration of total 6x10E7Bq of tritiated water in lots to a mouse produced no recognizable somatic effects.
4) Transfer factors on tritium behavior in rice and sweet potato were examined in heavy water release experiments.
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Research Products
(12 results)
