Age-dating of single particle of uranium standard material for nuclear forensics and safeguards

Okubo, Ayako; Esaka, Fumitaka  ; Magara, Masaaki  ; Shinohara, Nobuo 

To elucidate the final purification date of uranium material namely age-dating is important subject on nuclear forensic analysis. Age-dating of uranium using U-Th nuclide pair was established in the field of geochemical science, and has been applied for nuclear forensics. Recently, safeguard analysis also demand age-dating of uranium materials. In order to measure a small amount of Th by ICP-MS, anion exchange column separation is commonly conducted to eliminate U tailing effect. However, column separation step could raise procedural blank of Th. In contrast, TIMS can separately ionize U and Th in filament heating step using the difference of optical ionization temperature of these elements. We developed analytical method for age-dating of single particle uranium material by TIMS.