NEAR REAL TIME SYSTEM (NRTS) FOR SAFEGUARDS DATA EVALUATION AT THE FINNISH EPGR

The ONKALO® spent nuclear fuel dry storage is a deep geological repository being built near the Olkiluoto nuclear power plant off the southwestern coast of Finland. After encapsulation in copper disposal canisters, spent fuel from all of Finland’s nuclear power reactors will be deposited and permanently isolated approximately 450 meters below ground. International safeguards inspectorates from the IAEA and Euratom will jointly verify the movement of spent nuclear fuel from spent fuel ponds at the nuclear power plants to the encapsulation plant (EP) and along the entire process until emplacement in the geological repository (GR). During this process, continuity of knowledge will be maintained by highly reliable measures and instruments for containment and surveillance (C/S) and nuclear material monitoring. The equipment used to monitor the movement of nuclear material will generate a large amount of data, which must be evaluated by the international inspectorates in order to draw safeguards conclusions—without causing delays to EPGR facility operations. To facilitate an effective and efficient process for evaluation of the collected data, the IAEA, in cooperation with the European Commission (Euratom1), has started the development of a near real-time monitoring system (NRTS) which performs semi-automated data evaluation and prompts inspectors to act only at key decision points. Data collected from the unattended safeguards systems operating in a continuous mode without human intervention will be used by the NRTS as inputs for the verification software toolkits, whose algorithms are designed to aggregate information from different sources and compare the analysis results with the facility operator’s declared activities. A short time after data collection by the instruments, the NRTS software notifies both international inspectorates, the State authority and the facility operator that the required safeguards data have been collected, analyzed and verified against the operator’s declarations. In this way, the NRTS ensures that timely safeguards conclusions can be drawn prior to the execution of subsequent specific (essentially irreversible) disposal process steps, such as welding shut spent fuel canisters and depositing them in the Olkiluoto bedrock. This paper will describe the current development status of the NRTS and illustrate how it maps equipment data events to declared activities in a reliable and consistent way.