Development of analytical technique for safeguards environmental samples at JAEA; Current status and development of analytical method for isotope ratios of plutonium particles

Magara, Masaaki  ; Usuda, Shigekazu; Sakurai, Satoshi ; Shinohara, Nobuo ; Esaka, Fumitaka  ; Kokubu, Yoko   ; Suzuki, Daisuke   ; Yasuda, Kenichiro   ; Lee, C. G.; Inagawa, Jun; Onodera, Takashi; Fukuyama, Hiroyasu

JAEA has been developing, under the auspices of the Ministry of Education, Culture, Sports, Science and Technology of Japan, analytical techniques for ultra-trace amounts of nuclear materials in the environmental samples in order to contribute to the strengthened safeguards system. In January 2003, JAEA was qualified as a member of the IAEA network analytical laboratories (NWAL) for environmental sample analysis. Since then, JAEA has conducted the analysis of domestic and the IAEA samples. Two techniques, bulk and particle analyses, are available for the environmental samples and the latter method generally provides more detailed information about history of nuclear materials in a facility. However, isotope ratios of uranium are measured in the particle analysis at present and it is wished to develop analytical method for isotope ratios of plutonium in individual particles. We commence the development of the plutonium particle analysis and the consideration of age-dating for plutonium particles through the atomic ratio of Pu-241 and Am-241.