環境試料中の個々の粒子に含まれる核物質の同位体比分析

Isotope ratio analysis of individual particles containing nuclear materials in safeguards environmental samples

江坂 文孝  

Esaka, Fumitaka

保障措置環境試料中に含まれる個々の核物質粒子の同位体比分析のために、二次イオン質量分析法を適用し、検討した。また、試料からの粒子の回収方法について検討するとともに、あらかじめ試料中の核物質の量を高感度に調べるために全反射蛍光X線分析法を適用した。その結果、粒径1um程度の粒子の同位体比を効率的に分析する方法を確立した。

Isotope ratio measurement for individual particles containing uranium in swipe samples taken at nuclear facilities is a powerful tool to verify the absence of undeclared nuclear activities. In order to develop the analysis technique, we have investigated a series of methods: particle recovery from the swipe sample, particle screening and isotope ratio analysis for individual particles. As the result, the 235U/238U ratio was determined with the relative standard deviation within 2.0 % for the particle with a diameter of 1 um.