Verification measurements of the IRMM-1027 and the IAEA large-sized dried (LSD) spikes

Abstract

In the frame of the accountancy measurements of the fissile materials, reliable determinations of the plutonium and uranium content in spent nuclear fuel are required to comply with international safeguards agreements. Large-sized dried (LSD) spikes of enriched 235U and 239Pu for isotope dilution mass spectrometry (IDMS) analysis are routinely applied in reprocessing plants for this purpose. A correct characterisation of these elements is a pre-requirement for achieving high accuracy in IDMS analyses. This paper will present the results of external verification measurements of such LSD spikes performed by the European Commission and the International Atomic Energy Agency.

Preparation and characterisation of uranium and plutonium quality control samples for isotope dilution mass spectrometry measurements and uncertainty estimation

“…The reason for this observation could not be found. Such a positive bias when using the Pu KRI RM2 spike, was also observed during the verification measurements of the IRMM-1027r LSD spike [37]. Nevertheless, the agreement between the gravimetric value and the IDMS results using the two different spikes was fit for purpose for a QC sample to verify the Pu amount content in the solution.…”

“…However, with the KRI-RM-1 and -2 spikes some slight positive biases were observed in the IDMS results (Figs. 1 and 2), also when inter-linked with IRMM-1027r [37] and the most recent EQRAIN 16U. These IDMS results and spike CRMs will be part of the continuous in-house campaign on inter-linking JRC-Geel G.2′s and external spike CRMs, during which possible biases will be investigated.…”

“…Verification measurements of the 239 Pu amount content in the Pu QC solution (before dispensing) were carried out by IDMS using two 242 Pu spike materials, the Pu KRI-RM2 and the mixed 242 Pu/ 233 U IRMM-046c spike. The latter has been successfully used in various projects, including the certification of IRMM-1027 series LSD [37].…”

Precise U and Pu Isotope Ratio Measurements in Nuclear Samples by Hyphenating Capillary Electrophoresis and MC-ICPMS

“…The conventional protocol was developed in our laboratory for analysis of nuclear fuel samples 3 and the values presented here are comparable with those obtained by similar analytical protocols in other nuclear laboratories. [43][44][45] We observed a very significant decrease in term of analyzed quantities (from µg to ng), liquid waste volumes (from mL to µL) and sample volumes (from µL to nL). Moreover, the time of analysis was three times shorter.…”

30 years of IRMM-1027 reference materials for fissile material accountancy and control: development, production and characterisation

“…About 1000 units of IRMM-1027 LSD spikes are produced annually and certified in compliance with the ISO 17034 and ISO Guide 35 [14,15]. Spikes containing 235 U and 239 Pu have been successfully utilised in IDMS for safeguards inspections and in accountability measurements for operators at the reprocessing plants [9,10,[16][17][18][19][20]. The extensive use of LSD spikes over the past years has shown that IDMS, applying these spikes routinely, provides accurate results with measurement uncertainties below the target values as required by the safeguards authorities.…”