'This will be a real known process': Guarding against Mactaquac cost explosion

As anyone who has ever carried out a home renovation on an older property knows, sometimes surprises happen surprises that cause prices of the project to skyrocket.

Surprises can also happen with mega-projects, as NB Power knows from its recent experience in seeing its projected $1.4 billion-refurbishment of the Point LepreauNuclearGenerating Station go over budget by about $1 billion.

Now NB Power is embarking on the biggest infrastructure project in its history. It proposes renovations and repairs to the existing MactaquacGenerating Station that would allow the deteriorating dam to at least reach the end of its intended service life in 2068.

We know that we will have some surprises, but the numbers included some contingencies.- GaetanThomas, NB Power president

The projected cost: $2.9 billion to $3.6 billion.

NB Power's history of cost overruns at Point Lepreau could raise a question. What's to say the Mactaquacproject won't balloon in cost to something approaching twice the original estimate?

"We know that we will have some surprises, but the numbers included some contingencies," said NB Power president Gaetan Thomas. "So that's how you deal with the surprises.

"We also are going to deal with people that have done this before and have experience.

"So this will not be a first-of-a-kind. This will be a real known process, how to do it."

• 'The lake stays': NB Power opts to keep Mactaquac dam until 2068

The CANDU 6 reactor at Point Lepreau was the first of its type in the world to be refurbished to extend its operating life, contributing to the cost overruns.

Thomas points to BeauharnoisHydroelectric Generating Station along the St. Lawrence Seaway near Montreal as a power plant that has undergone a rehabilitation similar to what will take place at Mactaquac.

Beauharnois has 38 turbines compared to the six at Mactaquac and its rehabilitation projects are scheduled to run until 2021, just about the time work will be starting to ramp up at Mactaquac.

"It is really repair and maintenance," Thomas said. "A lot of the scope is still what we would have done if we didn't have any AAR issues," said Thomas, referring to the alkalai aggregate reaction issue that caused Mactaquac's concrete to deteriorate and shorten its natural lifespan of 100 years.

"The big, major equipment would have had to be replaced with or without AAR issues.

"When you look at the rest of the scope, it's actually quite small compared to a complete refurbishment or a new unit.

"The risk of surprises is lower than if you have a major refurbishment."