Final Results of the RISMET Project - Benchmarking of RI-ISI Methodologies

This paper describes the main results of the RISMET benchmark project, whose final report has been very recently published. THE RISMET project was launched in 2005 by the Joint Research Centre of the European Commission (JRC) together with the Nuclear Energy Agency of the OECD (NEA), with the aim of benchmarking several risk-informed in-service inspection (RI-ISI) methodologies. It featured more than twenty participating organizations from Europe, U.S., Canada and Japan, representing utilities, regulators and research organisations. In RISMET, various RI-ISI methodologies were applied to the same case, consisting of four selected piping systems at the Swedish Ringhals 4 PWR unit. The RI-ISI applications were compared among each other and to the deterministic ASME XI ISI selection procedure. The scope of the benchmark was limited to four systems, but the variety regarding safety class, potential degradation mechanisms and pipe break consequences ensured a good coverage of issues for a comparative study. The risk-informed methodologies showed some significant differences and resulted in slightly different risk ranking and selection of inspection sites. However, the results of the benchmark indicated that the risk impact of these differences is small, and the RI-ISI approaches identify safety important piping segments that are ignored by approaches not using the probabilistic safety assessment (PSA). The results of the benchmark exercise RISMET improve the knowledge on differences in approaches and their impact on plant safety, and promote the use of risk-informed ISI.

GANDOSSI Luca;  SIMOLA K.;  STEVENSON P.;  O'REGAN P.;  LYDELL P.;  HULTQVIST G.;  LEIJON A.;  ENGER K.; 

2013-03-21

Publications Office of the European Union

JRC58687

978-92-79-20321-3,   

1018-5593,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC58687,   

10.2790/31462,