Status of research to assess radiation effects on crack-arrest toughness of RPV steels

This paper provides an overview of work completed and in progress worldwide to study the effect of radiation on the static crack-arrest toughness, KIa, of reactor pressure vessel steels. The impetus for obtaining such data is the desire to realistically assess the need to repair or retire vessels that have been exposed to radiation in service, and to avoid the sometimes unnecessary conservatism associated with safety analyses when no KIa data are available. The paper reviews recent developments toward achieving an ASTM standard test method for measuring KIa. It demonstrates also the acceptability of using crack-arrest specimens that are appreciably smaller than those used frequently in the past, thereby increasing the practicability of studying radiation effects on KIa