Does the high-concentration radiocesium-containing insoluble particles affect the radiocesium contamination of rice?

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K02331
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 08030:Family and consumer sciences, and culture and living-related
• Research Institution: The University of Tokyo
• Principal Investigator: Higaki Shogo 東京大学, アイソトープ総合センター, 助教 (50444097)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 放射性セシウム / 放射性微粒子 / 分離 / イネ / 原発事故 / コメ / 不溶性微粒子

Outline of Final Research Achievements

Two RCsBPs were discovered from filters that filtered water collected from a waterway in Fukushima prefecture and succeeded in isolating them. Based on their radioactivity and the 134Cs/137Cs radioactivity ratio, both RCsBPs were determined to be derived from Unit 2. However, no RCsBPs were found in rice samples collected that year, so it cannot be concluded that RCsBPs are involved in the radioactivity contamination of rice. However, since RCsBPs were found in the waterway, it became clear that RCsBPs contained in soil and other substances flowed into the waterway due to factors such as wind and rain, contributing to the sudden increase in the radioactive cesium concentration in the waterway.

Free Research Field

放射化学

Academic Significance and Societal Importance of the Research Achievements

環境中に存在するRCsBPが、特に低濃度の放射性セシウム濃度の変動に大きな影響を及ぼす可能性を示した。
今回確立したRCsBPの分離手法・分離技術の最適化により、様々な試料から多量のRCsBPの単離が可能になった。また、長時間測定によるRCsBPの精密な放射能測定が可能になったことにより、主に事故直後にサンプリングした試料から多数のRCsBPの単離や評価が可能になった。本研究の本来の目的からは外れる部分があるものの、科学的に意義のある成果を出す基礎となる重要な技術であると考えている。