Workers on the Bruce A Restart Project have successfully completed the installation of new calandria tubes in the Unit 2 reactor, marking an industry-first for CANDU reactors worldwide.

Final seal tightness testing over the weekend concluded the work sequence, which saw 480 new calandria tubes installed, their end joints connected and sealed. The calandria tubes are installed horizontally in the reactor vessel and house the fuel channel assemblies that hold uranium fuel during operation. Each tube is approximately six metres long by 13 centimetres in diameter and manufactured from a zirconium alloy.

“The quality of workmanship, attention to detail and ability to deliver results in a tough work environment are a credit to the tradespeople, technicians and engineers who worked on the calandria tubes,” said John Sauger, Executive Vice President, Project Management and Construction.

The installation by Atomic Energy of Canada Limited (AECL) began on June 8, 2009. The last calandria tube was secured in the reactor on July 28, 2010 and the final seal tightness test was successfully concluded just after midnight today. To reach this milestone, AECL crews first spent more than two years removing the reactor’s original core components and preparing the vessel for new installation.

“Much of the work was completed with first-generation, remote-controlled tools to minimize worker exposure to radiation inside the reactor’s containment vault,” Sauger said.

Workers are now setting up equipment to install new fuel channel assemblies in the Unit 2 reactor. Ninety assemblies were installed in the upper portion of the reactor earlier in the project, but 390 remain to complete the task.

Reactor rebuild is also underway in Unit 1 with crews alternating between calandria tube installation and fuel channel assembly installation. The work in Unit 1 follows Unit 2 by about four months.

The four 750 megawatt units at Bruce A were laid up in the mid-1990s by former operator Ontario Hydro. Units 3 and 4 were restarted by Bruce Power earlier this decade; Units 1 and 2 are expected to synchronize with Ontario’s electricity grid in mid to late 2011 for another 25 years of production.

For stories and video clips on all aspects of the project, please check out our Bruce A Restart web pages at

About Bruce Power
Bruce Power is a partnership among Cameco Corporation, TransCanada Corporation, BPC Generation Infrastructure Trust, a trust established by the Ontario Municipal Employees Retirement System, the Power Workers’ Union and The Society of Energy Professionals.

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