Microbial influence on surface microstructural changes of uranium dioxide in aqueous environments

2024 Fiscal Year Final Research Report

• Project/Area Number: 21K14568
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 31010:Nuclear engineering-related
• Research Institution: Japan Atomic Energy Agency
• Principal Investigator: Kitagaki Toru 国立研究開発法人日本原子力研究開発機構, 福島廃炉安全工学研究所 廃炉環境国際共同研究センター, 主任研究員 (30770036)
• Project Period (FY): 2021-04-01 – 2025-03-31
• Keywords: 微生物 / 放射線 / 福島第一原子力発電所

Outline of Final Research Achievements

The objective of this study is to evaluate the microbially enhanced dissolution of uranium dioxide. To this end, it is essential to isolate and characterize microorganisms from environments rich in uranium dioxide.
In this study, stagnant water was sampled from Unit 2 of the Fukushima Daiichi Nuclear Power Plant nine years after the accident. Bacterial cultures were successfully obtained from this sample, and multiple strains were isolated. DNA was extracted from these strains and analyzed using next-generation sequencing. The sequences were assembled to determine the complete genome of each strain. By comparing the genomes with reference databases, the bacterial species were identified. However, partial discrepancies were observed between the isolated strains and the reference genomes, suggesting that DNA mutations may have occurred under high-radiation conditions, potentially leading to the acquisition of novel traits.

Free Research Field

原子力工学

Academic Significance and Societal Importance of the Research Achievements

本研究は、福島第一原発事故後の高放射線環境から微生物を分離・解析し、二酸化ウラン溶解への影響を評価したものである。得られた菌株のゲノム配列には基準株と異なる変異が認められ、放射線下での進化や新たな特性獲得の可能性が示唆された。これにより、極限環境における微生物進化の理解が進むとともに、微生物による核燃料の溶解機構解明に貢献する。さらに、放射性廃棄物管理や環境修復技術への応用が期待され、原子力災害後の生態系評価にも資する社会的意義を有する。