Age determination analysis of a single uranium particle for safeguards

Suzuki, Daisuke   ; Tomita, Ryohei ; Tomita, Jumpei  ; Esaka, Fumitaka  ; Yasuda, Kenichiro   ; Miyamoto, Yutaka   

An analytical technique was developed to determine the age of uranium particles for safeguards. After the chemical separation of uranium and thorium, the Th/U ratio was measured using single-collector inductively coupled plasma mass spectrometry and a U-based reference material comprising a certain amount of Th as a progeny nuclide of U. The results allowed us to determine the purification age of two certified materials, i.e., U-850 and U-100, which was in good agreement with the reference purification age (61 y). Moreover, the age of a single U-850 particle was determined with a difference of -28 to 2 years from the reference date.