Acoustic Emission Measurements during Fatigue Loading of Scaled Pressurized Water Reactor (PWR) Vessel at Joint Research Center of the European Communities (JRC), Ispra (Italy)

摘要

Fatigue tests on 1/5 scale models of PWR primary vessel are summarized. Acoustic emission (AE) measurements were made during hydrotests and fatigue cycling: continuously by JRC and CISE, periodically by UKAEA. Significant sources were detected and correctly located, also through the thickness. The fatigue propagation of a microdefect near the cladding (which gave clear signals during the first hydrotest) was clearly detected only during the last 30,000 cycles preceding the leak. The analysis of AE events clearly distinguishes friction/fretting noises from primary crack advance events, which, however, were too few or of too low energy to allow a completely satisfactory monitoring of crack propagation.