In-Plant Measurements of gamma-Ray Transmissions for Precise K-Edge and Passive Assay of Plutonium Concentration and Isotopic Fractions in Product Solutions. Final Report on TASTEX Task G

摘要

An instrument based upon high-resolution gamma-ray measurements has been tested for more than 1 year at the Tokai Reprocessing Facility for determination of plutonium concentration by K-edge absorption densitometry and for determination of plutonium isotopic fractions by transmission-corrected passive gamma-ray spectrometry. The nondestructive assay instrument was designed and built at Los Alamos National Laboratory for the Tokai Advanced Safeguards Technology Exercise (TASTEX). It was used at Tokai for the timely assay of more than 100 product solution samples during the TASTEX evaluations. The results were compared to reference values obtained by conventional destructive analysis of these samples. The precision and accuracy of plutonium concentrations measured by the K-edge technique are shown to be within 0.6% (1delta) in these applications. The precisions and accuracies of the isotopic fractions determined by these passive gamma-ray methods are shown to be within 0.4% for exp 239 Pu, 1% for exp 240 Pu and exp 241 Pu, and 10% for exp 242 Pu. (ERA citation 08:001811)