Degradation of CAN DU Fire Protection Systems: Past, Present and Future

Abstract

Recently, corrosion damage to the fire protection systems (FPSs) of some of the older CANDU stations has been reported. This corrosion damage has resulted in through-wall penetrations and leaks Similar observations have been made in US nuclear power plants where the older stations have had to make significant and costly repairs because of localized through-wall corrosion (pitting) in their FPSs. As a result of both layout and operational practices, it is apparent that the FPS is often susceptible to microbially influenced corrosion (MIC) causing through-wall pitting. In this paper CANDU case histories will be reviewed to show the nature, extent and mechanism of the MIC in the FPS. The paper will conclude with recommendations from both a future and operational perspective to remedy the situation and prevent recurrence.