Refurbished Bruce approaching full strength

18 October 2012

The second unit at the refurbished Bruce A nuclear power plant has sent electricity to the Canadian grid for the first time in 17 years, five months after its restart was postponed because of generator problems.

Testing Bruce A turbine (Bruce Power)_200
A Siemens Canada employee carries out tests on generator equipment at Bruce A2 (Image: Bruce Power)

The grid synchronisation of Bruce A2 signals the final stages of commissioning the 750 MWe Candu after seven years of refurbishment. This saw the replacement of all its pressure tubes and calandria tubes, electrical system upgrades, and the first ever replacement of a steam generator at a Canadian nuclear plant. The unit was ready to restart in May, but a problem with the electrical generator in the non-nuclear side of the plant resulted in a last-minute postponement. Bruce A1 went through a similar refurbishment and became the first of the pair to restart, synchronising with the grid in September.

Bruce Power president and CEO Duncan Hawthorne expressed his satisfaction that the project was moving into its final stages. "This gets us one step closer to the finish line and for the first time in nearly two decades we're in the midst of returning the site to its full operational capacity," he said.

Thirty-six hours after starting up, Bruce A2 was supplying 209 MWe to the grid. Final commissioning activities, including safety system shutdown testing, will now be carried out at Bruce A2 before it can go into operation at full power. Similar activities are already under way at Bruce A1, which is generating around 617 MWe. The electrical generator which caused the delay to Bruce A2's start-up had been replaced as part of the refurbishment project by Siemens Canada. To get Bruce A2 up and running, a generator unit from Bruce A4, which is currently undergoing a maintenance outage, was transferred to unit 2 in a first-of-a-kind operation. Bruce A3 is currently operating normally.

The Bruce site is home to Bruce A units 1-4 and Bruce B units 5-8. The four Bruce A units, all 750 MWe Candus, entered service in the second half of the 1970s but were laid up in the late 1990s by their owner at the time, Ontario Hydro. Bruce Power took over the operations of both Bruce plants from Ontario Hydro in 2001 and restarted units 3 and 4 by early 2004. Committed to phase out coal-fired generation, but faced with looming energy shortages, the Ontario government agreed with Bruce Power in 2005 to refurbish Bruce A. In 2010, the total cost of refurbishing units 1 and 2 was estimated at some C$4.8 billion (around $4.9 billion at current rates).

The four 822 MWe Candu units at Bruce B, which started up in the mid-1980s, have continued to operate while Bruce A was laid up and throughout the refurbishment work.

Researched and written
by World Nuclear News