Measurement of production date (age) of nanogram amount of uranium

Abstract

JRC-Karlsruhe obtained a swipe sample from a highly enriched uranium seizure, which had taken place in 2011. Due to the very low amount of uranium (nanograms) a new method needed to be developed to determine the U production date (age). The particles on the swipe were collected on a pyrolytic graphite planchet using a vacuum impactor and they were subsequently leached with ccHNO 3 . The "bulk" U isotopic composition ( 235 U: 72.51 ± 0.03 wt%) and the production date (December 1992 ± 1 year) determined by MC-ICP-MS indicated that the material showed similarity with two other HEU cases seized earlier in Europe.

Atomic spectrometry update: review of advances in the analysis of metals, chemicals and materials

“…Varga et al at JRC-Karlsruhe also used MC-ICP-MS to determine the U production age on particles collected on a swipe sample of enriched material that was seized in 2011. 204 Samples were measured following nitric acid leaching, with a 235 U composition of 72.51 AE 0.03 wt% and a production date of December 1992 AE 1 year, showing similarity with two other materials seized in Europe. Zhang et al used TIMS for U isotopic measurement related to nuclear safeguard and forensic applications, with a new lament carburisation technique used to enhance sensitivity for ultra-trace measurement.…”

Isotopic measurements using ICP-MS: a tutorial review

“…104 Finally, the dating of enriched uranium by MC-ICP-MS should be mentioned. 105 We will discuss some of the application elds focusing on the alternative ways used to measure accurate isotope ratios. The discussion is not intended to be exhaustive.…”

Atomic spectrometry update: review of advances in the analysis of metals, chemicals and materials

“…A second study by Varga used MC-ICP-MS to determine the U production date from a swipe sample of a highly enriched U seizure. 216 Measurements following acid leaching were used to calculate the ‘bulk’ composition (72.51 ± 0.03 wt% 235 U) and the production date, which was similar to other cases seized earlier in Europe. A separate study by Krachler et al used LA-MC-ICP-MS for the measurement of U isotopic composition in five contaminated scrap metal samples found in the EU.…”