Environmental radioactivity research on radio-iodine contamination by the Fukushima Daiichi Nuclear Power Plant accident

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K05205
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 34030:Green sustainable chemistry and environmental chemistry-related
• Research Institution: Gakushuin University
• Principal Investigator: Takeshi Ohno 学習院大学, 理学部, 教授 (40452007)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 放射性ヨウ素 / ICP-MS / MS/MS / 原子力発電所事故

Outline of Final Research Achievements

The accident at the Fukushima Daiichi Nuclear Power Plant resulted in a substantial release of radionuclides including Iodine-131, Cesium-134, and Cesium-137 to the atmosphere, and caused significant contamination of the environment. An effective dose estimation of released I-131 is important but difficult due to lack of data on the deposition of I-131. The long-lived radioiodine isotope I-129 is one of the important radionuclides released from nuclear fuel reprocessing plants and nuclear accidents into the environment. In particular, I-129 has been used as a tool to reconstruct the initial distribution of I-131 at nuclear accidents. In this study, the determination of I-129 in enviromental samples by ICP-MS/MS was performed, and the distribution of radioactive iodine released by the Fukushima Daiichi Nuclear Power Plant accident was examined.

Free Research Field

環境地球化学

Academic Significance and Societal Importance of the Research Achievements

福島第一原子力発電所の事故により、大量の放射性ヨウ素（I-131）が放出された。I-131は体内に入ると甲状腺がんのリスク要因となるため、環境中に含まれるI-131に関する情報は重要である。しかし、事故後数ヶ月でI-131の放射能を調べることは困難となったため、本研究では、事故により同様に放出された長半減期放射性ヨウ素（I-129）を用いてI-131を推定する迅速分析法を開発した。本研究で開発したICP-MS/MS法を用いた分析法は従来法に比べ１０倍以上迅速に測定することが可能になった。