Investigation Into the Potential Release of Chloride From the Moderator Cover Gas Recombiner Catalyst

Abstract

Corrosion has been identified in the Bruce-B Unit 7 Moderator Cover Gas System. A failure analysis was able to show that chloride induced transgranular stress corrosion cracking and pitting corrosion took place. Understanding the source of the chloride that caused this corrosion is critical if this corrosion problem is to be mitigated. A number of potential chloride sources have been identified. One such source is the catalyst that is used for recombining deuterium and oxygen in the moderator cover gas recombination units. In this paper the potential for release of chloride from the recombiner catalyst is addressed.