Status report on developments and cooperation on risk-informed inservice-inspection and non-destructive testing (NDT) qualification in OECD-NEA member countries - CSNI integrity and ageing working group

During the last decades the nuclear industry has experienced service degradation of many components, both in primary systems and in secondary systems. Several inspection failures have also occurred over the years. This degradation and inspection history as well as the economical and political factors have consequently set up a pressure for more efficient and cost-effective in-service inspection programmes to ensure that there are adequate safety margins so that anticipated degradations of components do not lead to failures that cause accidents or even unplanned shutdowns with adverse effects on power production reliability. In this situation, nuclear regulators as well as nuclear utilities in many countries have developed and implement risk-informed inspection approaches together with more stringent requirements of demonstrating the performance of the NDT systems that are to be used for inspection of safety related components which are susceptible to different kind of degradation mechanisms. In December 2000, the Committee on Nuclear Regulatory Activities (CNRA) and the Committee on the Safety of Nuclear Installations (CSNI) agreed to prepare a state-of-the art report addressing the present situation and regulatory aspects in NEA member countries on: - Risk based / risk informed in-service inspections developments, - Qualification of NDT system to be used for the inspections. The CSNI gave mandate to the CSNI working group on the Integrity of Components and Structures (IAGE) to prepare the report. Practices and status in NEA member countries were collected in 2003 through a questionnaire. Results have been compiled in the report NEA/CSNI/R(2005)3. To complete the technical information, a CSNI Workshop was held from 13 to 14 April 2004 in Stockholm, Sweden hosted by the Swedish Nuclear Power Inspectorate. The Workshop gathered 54 participants from 17 countries including the EC, the IAEA and the main organisations worldwide developing RI-ISI methodologies. Papers presented at the Workshop have been published in the proceedings referenced NEA/CSNI/R(2004)9. The two reports along with the NRWG-report EUR 21320 are the main source of information for this Status Report on Developments and Cooperation on Risk-Informed In-Service-Inspection and Non-Destructive Testing (NDT) Qualification in OECD-NEA member countries. The report is organized in the following way: introduction to early ISI strategies and Augmented ISI and NDT Qualification; Risk-Informed In-Service Inspection (RI-ISI): Development of RI-ISI strategies, RI-ISI Regulatory guidance, Important aspects of RI-ISI, Overview of RI-ISI methods, Comparison of methods, Overview of RI-ISI applications and pilot studies, RI-ISI experience so far, Further evaluations and developments of RI-ISI methodologies; Non-Destructive Testing (NDT) Qualification: Development of NDT qualification strategies, NDT-qualification requirements and applications, NDT-qualification experience. Conclusions and recommendations are then given