Energy Minister Bob Chiarelli will announce the province's plan to refurbish Ontario's aging nuclear energy infrastructure before his speech to the Canadian Club of Toronto on Thursday.

Details will be unveiled to reporters early Thursday morning, the minister's office has announced.

The contents of the plan remain under wraps. However, Chiarelli was asked whether the contents of the auditor general's report, which was released Wednesday and revealed customer-service problems in Ontario's energy sector, will impact his announcement.

"Come to my speech tomorrow," Chiarelli replied.

"There has been layer on layer on layer of due diligence that has been done," he said of his department's plans.

"There has been razor-sharp focus on price, and we also have built in to the process, and I'm giving you a little bit of a lead here, some off-ramps. There are long-term commitments, but there are off-ramps that enable us to change direction if need be."

The plans should largely focus on the Darlington nuclear station, which went online in the early 1990s and currently supplies about 20 per cent of Ontario's power. The refurbishment is slated to take about 10 years.

The plans will also include the refurbishment of the Bruce Power nuclear facility in Tiverton, on the shores of Lake Huron.

Asked how confident he is of the Liberal government's plan for nuclear refurbishment, Progressive Conservative energy critic John Yakabuski questioned its record on the energy file.

"The record doesn't indicate that they get many things right in the energy sector. But, having said that, I think it's high time that some decisions were made with regards to nuclear generation," Yakabuski told reporters at Queen's Park.

"They've been twiddling their thumbs and spinning their wheels for a long time while the day of decision gets closer and closer where we're going to have a situation where we'd have to take nuclear units down and not have enough nuclear capacity in the system to ensure that we have reliable, clean affordable power."

If nuclear plants have to be taken off-line at the same time, he said, the province will have to rely on less environmentally-friendly energy sources to make up the difference, "which flies in the face of their claim that everything they're doing is about climate change."

On Thursday, Chiarelli said the government is "confident" that it has "smart" plans for both the Bruce and Darlington facilities.