Gentilly-2 Internal Initiating Events Frequencies Estimation for Level 1 PSA: The Need for Shared Generic CANDU Frequencies

Abstract

One of the most commonly used methods to derive site specific Initiating Events (IEs) frequencies is to obtain statistical estimates based on operating experience data (OPEX) as reported by the station. Likely, IEs occurrences are not that common to be able to estimate the IE frequency solely based on site data. Thus, a wider generic data source is usually needed and combined with the site data using a Bayesian approach in order to have statistically meaningful frequencies. G-2 site specific events are analyzed from the station in-service date in 1983 to December 31st 2006. Generic events from the Canadian station are analyzed for five years (2002 to 2006) based on Licensee Event Report (LER) found in « COG OPEX database ». The IE frequency is then estimated using a Bayesian update process.