REIMEP-22 inter-laboratory comparison: “U Age Dating – determination of the production date of a uranium certified test sample”

Measurement of the 231Pa/235U ratio for the age determination of uranium materials

“…For IRMM-1000 both obtained values are slightly lower than the certified age. Although this is not significant, it was also observed during the REIMEP-22 inter-laboratory comparison [ 18 ]. For U100 the measured 231 Pa/ 235 U production dates are in agreement with the purification date of 8 January, 1959 [ 8 ].…”

Determination of picogram amounts of uranium in micrometre-sized particles by isotope dilution mass spectrometry

“…The uranium amount per particle and its associated uncertainty as quantied in this study in the particles reference material IRMM-2329P, was further conrmed during the Prociency Test NUSIMEP-9 (Nuclear Signatures Interlaboratory Measurement Evaluation Programme) organised by the JRC-Geel G.2 unit. 20 One NUSIMEP-9 participating laboratory, expert in the eld of particle analysis, using LG-SIMS and calibrating against a specic batch of microspheres CRM U020-A according to Ranebo et al, 21 determined the uranium amount per particle with a relative difference to the reference/certied value of only À0.6%.…”

Contribution of the Faraday cup coupled to 10 12 Ω current amplifier to uranium 235/238 and 234/238 isotope ratio measurements by thermal ionization mass spectrometry

“…Safeguard authorities requirement for 235 U abundance measurement uncertainty by Thermal Ionization Mass Spectrometry (TIMS) is set to 0.28 % (k = 1) [3]. The detection of 234 U is of prime interest in nuclear forensics [4]. Also, for a given sample, the relative amount of 234 U dramatically changes its radiotoxicity [5].…”