Recommendations for measurement systems for nuclear material accountancy of Fukushima Daiichi fuel debris; technologies

福島第一原子力発電所の燃料デブリの線による測定技術の検討

富川 裕文; Heinberg, C.; 名内 泰志*; Vo, D.*; Carroll, C.*; 堀 啓一郎

Tomikawa, Hirofumi; Heinberg, C.; Nauchi, Yasushi*; Vo, D.*; Carroll, C.*; Hori, Keiichiro

福島第一原子力発電所の燃料デブリ中の核物質量を測定する技術については原子力機構と米国エネルギー省が協力して検討を進めてきた。日米のメンバーで構成する線測定技術のついて検討するワーキンググループ設置され、このグループにおいて測定器のコストや大きさ、測定時間、開発期間などの燃料デブリへの適用性を検討した。この結果に基づく測定システムの提案を行う。

In order to survey technologies to be developed for nuclear material quantification of fuel debris at 1F, Japan Atomic Energy Agency (JAEA) and United States Department of Energy (DOE) started collaborative research from November 2012. Under the collaborative research, three Working Groups, Neutron Working Group (NWG), Gamma Working Group (GWG) and Source Term Working Group (STWG) were established. The roles of GWG are to identify measurement systems that could be studied further for possible implementation at 1F. Candidate measurement technologies are Gross Counting, Dosimetry, -ray Spectroscopy, -ray Densitometry, -ray Imaging, Transmission (X-ray) Radiography, Prompt Fission -ray Counting and Spectroscopy, and Neutron Induced -ray Spectroscopy. Taking into account system cost, system size, measurement time, development period, and potential for applicability to fuel debris, GWG members have identified recommended combinations among the technologies supplemented with neutron measurement technologies. The evaluation was carried out by literature search and simulation works. This paper provides recommendations of the GWG for measurement systems based on mainly measurement technologies for nuclear material accountancy of fuel debris at 1F.