French plant life management program - RPV integrity assessment

Full text: INTRODUCTION. The Lifetime Management Program of 58 Pressurized Water Reactor (PWR) units was started a few years ago by Electicite de France (EDF) the French utility. Reactor Pressure Vessel (RPV) which is one of the major components is involved in the French PLIM of the 34 threeloop and 24-four loop units. The RPV life management program is mainly based on design and fabrication data, analysis of margins against the rupture risk, surveillance programs (inservice inspection, fluence measurement, monitoring of material radiation effect, transients). INTEGRITY ASSESSMENT METHODS. This paper presents an overall review describing the French approach, based on different analytical studies in agreement with French regulation: on the one hand a generic analysis for each series of similar plants and on the other hand a specific analysis vessel by vessel. The goal is to evaluate the margins on different parameters such as RTNDT, toughness, or crack size in order to demonstrate the RPV integrity for all categories of conditions (normal, upset, emergency and faulted) and therefore to assure high safety level in operating of all these RPV for, at least, 40-years lifetime. CONCLUSION. According to the results, the EDF's maintenance strategy based on RPV in-service inspection and program of actions is introduced. The global results of integrity evaluation for Reactor Pressure Vessel in all cases of situations are presented. (author)