LAUSR

Developing different model age determination methods of uranium sample could get more information on insight into source and suspected use in nuclear forensic investigation. A procedure for the determination of model age of uranium sample using 231Pa/235U radiochronometer was reported. The 233Pa spike used in the procedure of 231Pa–235U model age determination was separated from in-house 237Np stock solution by using two TRU resin columns and three silica gel columns and calibrated by CRM U100. Model ages of CRM U010 and IRMM-1000b were presented. The model age of IRMM-1000b using 231Pa/235U radiochronometer were older than the literature reported results by 230Th/234U radiochronometer by amounts exceeded the expanded uncertainty.