Preparation and evaluation of reference materials for accountancy analysis, 2; Evaluation results

Sumi, Mika; Abe, Katsuo; Kageyama, Tomio ; Nakazawa, Hiroaki; Takamatsu, Mai*; Katchi, Tomokazu*; Murakami, Yoshiki*; Ai, Hironobu*

Destructive analysis for accountancy at nuclear fuel facilities should attain international target values for measurement uncertainties in safeguarding nuclear materials (ITVs).Since measurement uncertainties of isotope dilution mass spectrometry depend on uncertainties of standard materials (spikes) used, utilizing highly reliable standard material is essential. The LSD spikes prepared under collaboration work with JAEA and JNFL has different Pu/U ratio and smaller nuclear material in a spike compared with the LSD spikes used at safeguard laboratories, and the value of Pu which separated and purified from MOX and used as raw material for one of the LSD spike prepared at JAEA were measured at JAEA. Uncertainties of the prepared LSD spikes and the measurement results of actual samples with these LSD spikes were evaluated based on ISO-GUM and compared with ITVs.