On-Site Bias Defect Verification Using the COMPUCEA Mobile Analytical System: Implementation in International Safeguards Practice

摘要

The 2nd generation Combined Procedure for Uranium Concentration and Enrichment Assay(COMPUCEA) is a transportable analytical measurement system that combines the L-edgetransmission and γ-ray spectrometry for high-accuracy on-site uranium concentration andenrichment assay of uranium bearing materials. The hardware and methodology were developedat the Institute for Transuranium Elements (EC JRC ITU) and since 2007 COMPUCEA has beenin routine use by Euratom for physical inventory verification (PIV) campaigns at European fuelfabrication plants. In terms of analytical performance, COMPUCEA meets current InternationalTarget Values (ITV2010) guidelines for destructive assay (DA), with a relative combineduncertainty of ≤0.4% and ≤0.2% for ~(235)U enrichment (ITV2010 = 0.45%) and uraniumconcentration (ITV2010 = 0.28%), respectively. The COMPUCEA has all the potential to serveas an on-site bias defect verification method. The current paper describes recent efforts towardthe implementation of COMPUCEA at the international safeguards level. Here we present, interalia; (ⅰ) a summary of the establishment of a fully integrated measurement system, comprisingspecialized hardware and software; (ⅱ) the evaluation and benchmarking of the system’sperformance; (ⅲ) the build-up of IAEA's expertise in performing COMPUCEA analysis in thefield; (ⅳ) the improvement of the tamper resistance of the method through execution of avulnerability assessment exercise; (ⅴ) the development and implementation of dedicatedtheoretical and practical training courses for IAEA inspectors, and (ⅵ) the deployment of thesystem during PIV campaigns at the Ulba Metallurgical Plant in Ust-Kamenogorsk, Kazakhstan.