Costs unknown as N.B. Power deals with breakdowns at 2 key generating stations

Hope for a quick return to service for the Point Lepreau nuclear generating station was fading Thursday as crews worked to fix a problem that triggered a shutdown at the critical but trouble-plagued plant early Wednesday morning.

That's putting immediate pressure on N.B. Power's finances, which are already burdened by an ongoing breakdown at its natural gas generating station that would normally help replace energy from the idle nuclear plant.

So far N.B. Power has said only that a "leak" was discovered in part of Lepreau's non-nuclear system that transports heat generated in its reactor to the plant's conventional boilers. The boilers produce steam that drives Lepreau's electricity generating turbines. 

However, the utility was hinting a fix would not be immediate.

"Investigation and assessments are underway in order to determine the path forward," it said in a statement Thursday.

Lepreau is N.B. Power's most important, and when it is operating its most lucrative generating station. But before the current shutdown, it was already having its worst year of production since coming out of a major refurbishment a decade ago.

An April maintenance outage that N.B. Power had hoped to keep to 10 weeks, dragged on for longer than 17 weeks as more issues than expected showed themselves.   

In evidence filed with the New Brunswick Energy and Utilities Board in October, N.B. Power revealed that the extended spring and summer outage meant it was only expecting to produce four million megawatt hours of electricity from Lepreau this year.  

That is one million fewer than last year and the lowest in any year since the plant emerged from a 4½-year refurbishment in 2012.

In addition, N.B. Power's natural gas generating station at Bayside in Saint John, which sometimes fills in for Lepreau during outages, also remains idle after suffering a catastrophic breakdown last winter.

N.B. Power initially planned for a return to service for Bayside this fall, but now says it won't be operating until January.

That will force NB Power into the marketplace to replace at least some of the energy from Lepreau which is normally priced at a premium during cold weather months.

N.B. Power's Dominique Couture said in an email that the utility will "be utilizing our interconnections to purchase energy as required."      

"Costs are unknown at this time," she wrote.

In the past N.B. Power has said shutdowns at Lepreau cost it $1 million per day, but that likely understates the expense it faces at this time of year.

N.B. Power executives have long pointed to the efficient operation of the Lepreau nuclear generating station as the key to its financial health.

The plant was meant to operate for 210,000 "effective full power hours" over 27 years following its renovation. However, at the end of March this year, it had logged 67,613, hours, a little more than 8,000 behind that original schedule.   

Troubles at Lepreau this year, including this week, have put it a further 1,300 hours behind that original target. 

Every hour of full production at Lepreau generates about $50,000 worth of electricity to sell.