Results of interpretive acoustic emission testing of mechanically and thermally loaded reactor pressure vessels

AE measurements are presented which were performed at pressure vessel components during different loadings: thermal shocking, hydrotest, cyclic loading. The tests were executed with the IzfP AE system. With this system it is possible to locate the AE sources and to identify two source mechanisms: crack growth and crack flank friction. The AE results are discussed and compared with the results of calculations about the residual stress in a cladded vessel wall: AE signals originating from crack growth processes are detected very sensitively; During thermal shock a lot of crack border friction occures in consequence of compressive stresses on the crack flanks; However, during the hydrotests no crack border friction appears, because the crack flanks are mainly under tensile stresses. (IZFP)