The application of multiple radiochronometers in a forensic investigation of bulk uranium provides increased confidence for interpreting age-dating results. We have developed a streamlined method for the purification of Pa and Th from bulk uranium and have applied this method in analyzing uranium CRMs IRMM-1000a and CRM U100, using the 231Pa-235U and 230Th-234U radiochronometers. Our improved 233Pa spike calibration technique has replaced the time-intensive, conventional calibration using geologic rock standards. Paired Pa-U and Th-U age-dating analyses of CRM U100 produce concordant results. In contrast, analyses of IRMM-1000 demonstrate reproducibly-discordant Th-U and Pa-U age-dates.
Revised: August 23, 2019 |
Published: October 31, 2018
Citation
Treinen K.C., A.M. Gaffney, J.M. Rolinson, K.M. Samperton, K.C. McHugh, R. Williams, and M.M. Miller. 2018.Improved protactinium spike calibration method applied to 231Pa-235U age-dating of certified reference materials for nuclear forensics.Journal of Radioanalytical and Nuclear Chemistry 318, no. 1:209–219.PNNL-SA-137585.doi:10.1007/s10967-018-6149-x