Bruce Unit 1 & 2 Preheater Condition Assessment & Refurbishment

Abstract

Bruce Units 1 to 4 were shut down during the 1990s, largely as a consequence of tube degradation resulting from inappropriate steam generator secondary side water chemistries. Following a condition assessment, Bruce Power restarted Units 3 and 4 and is currently refurbishing Units 1 and 2. In order to assess the condition of the Unit 1 and Unit 2 preheaters and determine their suitability for extended operation, inspection, maintenance and assessment activities have been conducted. Eddycurrent and visual inspection have revealed vessels in generally good condition. Secondary side internals appear largely undegraded. Some tube to support fretting has been observed, and a number of tubes have been removed from service because of debris fretting concerns. To prepare for return to service, the primary side divider plates have been replaced and the tubes have been ID cleaned to restore the preheater to its original condition. This paper summarizes the inspection planning, findings, assessment for extended operation and maintenance activities undertaken.