Bruce B vacuum building inspection and maintenance program complete

The Bruce B vacuum building inspection and maintenance program is complete.

Done about every 10 years and requiring all four units at Bruce B shut down, the work wrapped up safely earlier this week.

 

Unit 8 was the first to return to the provincial grid Sunday evening, followed by Unit 5 Sunday night, with Unit 7 returning to service on Monday. A planned maintenance and inspection program on Unit 6, that began in early April, continues and is scheduled to wrap up in the third quarter of 2015.

 

“This outstanding result can be attributed to an unwavering commitment to safety, a strong operational focus, hard work, effective teamwork and a high level of engagement,” says Brian O’Grady, senior vice-president at the Bruce B generating station. “I want to thank our staff for all their hard work and dedication. This is something we can all be very proud of.”

 

An additional 300 temporary workers were on-site during this $30-million investment program.

 

The 45-metre-high vacuum building is a concrete structure with walls approximately one-metre thick, and is a unique safety feature of CANDU reactors designed to protect the public, employees and the environment by preventing the release of radioactivity in the unlikely event of a large loss of reactor coolant.

 

During normal operation, the air inside the vacuum building is maintained at one-tenth atmospheric pressure by vacuum pumps in the upper and lower chambers. The vacuum building is separated from the station containment structure by an array of 18 large pressure relief valves which are connected to massive tubes at the base of the vacuum building. In the event of a loss of coolant, any radioactive steam would travel into the vacuum building and be doused with water and contained.