Development and use of the R5 procedures for the assessment of defects in high temperature plant

摘要

The R5 procedures have been developed within the UK power generation industry to assess the integrity of nuclear and conventional plant operating at high temperatures. Within R5, there are specific procedures for assessing components containing defects. These are largely based on approximate reference stress techniques and are continuing to be developed. This paper describes the procedures for assessing the incubation and growth of defects at elevated temperatures and includes examples of both experimental and finite-element validation of these approaches. The use of these basic procedures is then illustrated by application to a typical high temperature plant component. Alternative methods for assessing incubation and the early stages of creep crack growth are currently being developed within the R5 procedures and this paper finally describes one of these, the time dependent failure assessment diagram (TDFAD) approach.