IAEA保障措置における転用探知概念に関する調査

Investigation of the concept of detection of diversion in IAEA safeguards

秋葉 光徳*

Akiba, Mitsunori*

バルク取扱施設における基本的に重要な転用探知手段として計量管理がある。これに基づく転用探知概念は、IAEA発足当初から基本的に変わっていないものの、査察経験、検認機器の開発等に伴い、1992年以降、査察計画は破壊分析から非破壊分析に重点が移された。その後も若干の見直しがあったことから、標記概念について調査した。

Nuclear material accountancy begins with the nuclear material accounting activities which are undertaken by facility operators. These activities and corresponding accounting information generated are verified through independent inspections. For bulk handling facilities, two diversion strategies, diversion into D and diversion into MUF, could be assumed. These diversion strategies have to be detected by inspectorate quantitatively. Inspection goals, that is, significant quantities, detection time and detection probability is set in advance. Based on the detction goal amounts, sample sizes are calculated for gross defect, partial defect and bias defects testers. Major defects could be detected by these three verificatuin testers, this is called Item-D statistics.Remaining of major defects which is small defects could be detected by Material Balance-D statistics. Diversion into MUF could be detcted by MUF statistics. Overall detection capabilities are the combination of these three statistics.