NUCEFにおけるウラン系臨界実験に関する分析の現状

芳賀 孝久*; 軍司 一彦; 深谷 洋行; 薗田 暁; 坂爪 克則; 境 裕; 新妻 泰; 冨樫 喜博; 宮内 正勝; 佐藤 猛; et al.

JAERI-Tech 2004-005, 54 Pages, 2004/02

JAERI-Tech-2004-005.pdf:2.06MB

燃料サイクル安全工学研究施設(NUCEF)の定常臨界実験装置(STACY)及び過渡臨界実験装置(TRACY)においては、硝酸ウラニル溶液を用いた臨界実験が実施されている。NUCEFの分析設備では、臨界実験,溶液燃料の調製,管理及び保障措置に必要な溶液燃料の分析を実施している。分析試料数は年間約300程度であり、分析項目は、ウラン濃度分析,遊離酸濃度分析,ウラン同位体組成分析,核分裂生成物(FP)核種濃度分析,リン酸トリブチル(TBP)濃度分析,不純物濃度分析等となっている。本報告書は、これまでのウラン系臨界実験に適応してきた分析方法と分析の品質管理についてまとめたものである。

US-Japan nuclear forensics analysis to identify the origins and process history of UOCs

Shollenberger, Q. R.*; 木村 祥紀; Inglis, J. D.*; Lindvall, R.*; 西脇 大貴; 山中 澪奈; 海野 勇次*; 細井 雅春*; Marks, N.*; Kips, R.*; et al.

no journal, , 

Uranium ore concentrate (UOC), or yellowcake, is a precursor material for nuclear fuel and is formed when uranium ore has been mined and milled (chemically processed). UOC is a commercially and internationally traded product, and several cases have been reported where UOC was found outside regulatory control or interdicted as part of a law enforcement investigation. Consequently, we need to advance our understanding of nuclear forensic signatures to identify the origins and process history of UOCs. Such signatures include the concentration of uranium (U), other minor and trace-level constituents, and isotopic composition of U or strontium (Sr). However, the interpretation of these nuclear forensic signatures can be difficult due to various types of uranium mining techniques, as well as the processing of U ores to UOCs. Therefore, multiple nuclear forensics signatures are necessary to determine material origin with high confidence. Through the Office of Nuclear Smuggling Detection and Deterrence (NNSA/US DOE/NSDD), we present the analysis of seven UOCs provided by the Japan Atomic Energy Agency (JAEA). Nuclear forensic measurements were performed on these UOCs at four different laboratories located in both the US and Japan. This study will focus on the signatures of uranium concentration, trace elements, and U and Sr isotopic compositions. We will discuss the results from the different laboratories and evaluate the importance of these signatures in the context of nuclear forensics.