Proactively Monitoring the Quality of the Operator's Measurement and Accountancy Systems in the Framework of Trilateral Liaison Meetings – Experiences Gained and Maturing the System

Two of the major objectives under a Comprehensive Safeguards Agreement (CSA) are to detect any diversion of declared nuclear material at facilities and locations outside facilities (LOFs) and to detect any undeclared production or processing of nuclear material in declared facilities and LOFs. The effectiveness of the IAEA in addressing these objectives is strongly influenced by the quality of the State and/or Regional Authority system of accounting for and control of nuclear material (S/RSAC), and on the nuclear fuel cycle facility operators' capabilities to establish and keep track of accurate and precise accountancy values on the inventories and flows of nuclear material at facilities and LOFs. Cooperation and information exchange between the IAEA, S/RSAC and facility operators on performance evaluations of the accountancy and measurement systems are an important factor in establishing and maintaining an effective and efficient evaluation system based on which the IAEA can draw sound safeguards conclusions. Reviewing material balance evaluation results, trends in accountancy declarations, measurement results and their associated uncertainties in a trilateral framework assures the proactive and timely identification of potential problems affecting the drawing of safeguards conclusions and facilitates a swift response in clarifying questions and addressing emerging accountancy or measurement issues. Over the past five years, facility-type specific trilateral meetings have been regularly held in Japan with the Japan Safeguards Office (JSGO), the Nuclear Material Control Center (NMCC) and the respective facility operators for Uranium fuel fabrication plants and for Plutonium bulk-handling facilities, and trilateral meetings have also taken place with the Brazilian–Argentine Agency for Accounting and Control of Nuclear Materials (ABACC), the Canadian Nuclear Safety Commission (CNSC) and the European Commission (EC) as well as individual facility operator's to address accountancy issues. These meetings have in numerous ways shown the importance of such forums which include all responsible parties: as an efficient platform for addressing and resolving immediate, and at times also long-standing, accountancy and measurement issues; as an opportunity for enhanced cooperation which reinforces mutual trust and transparency; and as a chance to foster exchanges of measurement data and discuss developments in statistical methodologies related to accountancy and measurement performance evaluations. (author)