Use of simulation in the NDE qualification process in France: application to the EPR RPV inspection

Abstract

The French Ministerial Order of 10 November 1999 requires the qualification of all NDE carried out on the Main Primary Circuit of a Nuclear Power Plant in France. This applies equally to the In-Service Inspection of the existing fleet as to the Pre-Service, and eventual In-Service, Inspection (PSI and ISI) for the European Pressurised-water Reactor (EPR) New Build programme in France. The qualification procedure establishes the level of performance guaranteed by each inspection process (in terms of coverage of the zone to be inspected, sensitivity of the process, and defect sizing and positioning), and is supported by three elements: engineering reasoning, simulation and physical trials. This paper will explore the use of simulations in the qualification process to be carried out on the EPR in France, building on the experience from the existing fleet. The focus will be on the influence of the identified variables on the process performances through the use of ultrasound (US) simulations (based on CIVA software). Comparison will be made with the final physical trials to consolidate the findings. The process will be illustrated by real applications relating to the Reactor Pressure Vessel (RPV), in particular to the flange boltholes.