Analysis of data related to ageing of VVER-440 NPP components : APSA network task 4 : POS task 4

The aim of case study was to demonstrate the applicability of methods for reliability parameters estimation, presented in the guideline (EUR 23954 EN), using the operational data from VVER-440 plants. Two types of calculations were performed, using Excel functions and WINBUGS scripts, to identify the possible trends of data. The study results are useful in revealing the problematic issues connected with use of data guideline (EUR 23954 EN) and for improvement of decision making process based on calculation results. Practical insights, recommendations and limitations are also discussed. The report was prepared by the Nuclear & Radiation Safety Center (NRSC), Yerevan, Armenia, in cooperation with the Institute for Energy, EC Joint Research Centre, Petten, Netherlands, in the framework of the EC JRC Ageing PSA Network Task 4 activities.