Procedure for assessment of WWER reactor pressure vessel materials degradation

摘要

The paper describes a new procedure prepared for assessment of reactor pressure vessel materials degradation of WWER type reactors in the Czech Republic.This procedure has been prepared within activities of the Czech Association of Mechanical Engineers (ASI) and represents a part of the global procedure for assessment of WWER component lifetime.This procedure takes into account possible damaging mechanisms and their consequences in material property changes. Fracture mechanics approach is applied using "critical temperature of brittleness" as a "reference temperature". Transition temperatureshifts are determined not only from Charpy impact notch toughness tests, but also from static and dynamic fracture toughness tests.Surveillance specimens programs of Czech WWER reactors have been designed and/or modified to comply these requirements.