MONITORING AT THE OLKILUOTO REPOSITORY SITE SUPPORTS FOR SAFEGUARDS FINDINGS

摘要

At the Olkiluoto repository site, the operator Posiva Oy runs a multidisciplinary monitoring program targeted at studying environmental impact, improving the understanding of the natural properties of the site, verifying favorable conditions for long-term safety, and developing methods for monitoring the performance of engineered barriers. The usability of the data produced by the monitoring program for the implementation of nuclear safeguards is assessed, primarily to detect the excavation of any undeclared underground premises. Microseismic monitoring is currently the only method whose results, located seismic events in Olkiluoto and surroundings, are already used in implementing national safeguards. It is concluded that automatic hydraulic head measurements in deep drillholes and land use monitoring also produce relevant data and findings for safeguards purposes. The inclusion of the results of hydraulic head and land use monitoring in the input for the implementation of national safeguards could apparently be achieved by examining material and reports that Posiva already delivers or reports to the national regulator STUK. It is proposed that STUK can make use of the wide monitoring data and assessment of the repository performance while making its safeguards findings. The IAEA can use the original reports as open source information for its data analytics, and also when ascertaining the national findings.