This report presents the essential results of study performed by European Clearinghouse on Operational Experience Feedback in cooperation with IRSN and GRS aiming to analyze the impact of inappropriate components supplied to NPPs on safety. Study has been performed by means of extracting, systematizing and analyzing of adequate operational experience related information from event reports stored in the relevant data bases. Methodology of study includes identifying, highlighting and examining of circumstances, precursors, causes and safety significance of said events, as well as of most important corrective actions, lessons learned and recommendations. Trying to evaluate impact of different potential sources causing incidents the entire nuclear supply chain as a whole is covered, and all stages of this system including design, manufacturing, storage, transportation are taken into account in the developed system of 7 subfamilies. The main defence lines of the licensee designed to prevent penetration of substandard components such as thorough preparation of the procurement documentation, source inspection prior to authorizing release for delivery and inspection/testing of items on receipt are considered as well.
Based on the results of performed analysis major contributors to the existing problem were identified. Among the analyzed subfamilies deficiencies in design cause about 42% of selected events and manufacturing faults cause 32%. The most frequently failing are mechanical (including hydraulic/ pneumatic) components (40 - 55% of relevant events) and electrical elements – they take 30 - 37% of total events number respectively. The worst vulnerable specific types of components are also identified: they are valves and seals among mechanical components, circuit breakers and relays among electrical components. Scrutinizing the lessons learned from the analyzed events and looking beyond the component-specific or condition-specific ones some generically applicable recommendations for preventing or decreasing the probability of supply to NPPs of inappropriate products and components are formulated.
ZIEDELIS Stanislovas;
2012-09-13
Publications Office of the European Union
JRC71056
978-92-79-25680-6 (print),
978-92-79-25679-0,
1018-5593 (print),
1831-9424 (online),
EUR 25420 EN,
OP LD-NA-25420-EN-C (print),
OP LD-NA-25420-EN-N (online),
https://publications.jrc.ec.europa.eu/repository/handle/JRC71056,
10.2790/60265 (print),
10.2790/59395 (online),
