Improved protactinium spike calibration method applied to 231Pa–235U age-dating of certified reference materials for nuclear forensics

• Published in: Journal of radioanalytical and nuclear chemistry Vol. 318; no. 1; pp. 209 - 219
• Main Authors: Treinen, Kerri C., Gaffney, Amy M., Rolison, John M., Samperton, Kyle M., McHugh, Kelly C., Miller, Martha L., Williams, Ross W.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Cham Springer International Publishing 2018; Springer Nature B.V
• Subjects: Age; Calibration; Chemistry; Chemistry - Radiation chemistry, radiochemistry, and nuclear chemistry; Chemistry and Materials Science; Chronology; Diagnostic Radiology; Forensic engineering; Hadrons; Heavy Ions; Inorganic Chemistry; Nuclear Chemistry; Nuclear Physics; Physical Chemistry; Protactinium; Reference materials; Thorium; Uranium; Radiochronometry; Protactinium; Age-dating; Thorium
• ISSN: 0236-5731; 1588-2780
• DOI: 10.1007/s10967-018-6149-x

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 certified reference materials (CRMs) IRMM-1000 and CRM U100, using the
231
Pa–
235
U and
230
Th–
234
U radiochronometers. Our improved
233
Pa 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.