Ontario's provincial government last year also provided cash to lay the groundwork for the project, which could add up to 4,800 megawatts (MW) of capacity, almost doubling the output of the Tiverton, Ontario, location.

Canada and Ontario are seeking to expand grid capacity and reduce carbon emissions at the same time, and both the federal and provincial governments see nuclear power as a way of achieving this in the country's most populous and industrialized province.

Both Ontario and Ottawa "have an interest in building a grid that is going to be non-emitting, but also obviously affordable, reliable, and a grid that actually has sufficient capacity to actually do things like attract industry," Energy and Natural Resources Minister Jonathan Wilkinson told Reuters ahead of the announcement.

Ontario Energy Minister Todd Smith has agreed to work with Prime Minister Justin Trudeau's government to meet federal clean electricity ambitions, Wilkinson said. The aim is to make Canada's power grid emissions-free on a net basis by 2035.

Bruce Power, which is partly owned by TC Energy, already supplies 30% of the province's electricity. No new nuclear reactors have come on line in Canada in more than 20 years.

The federal money will help Bruce Power conduct early engagement activities with local municipalities and Indigenous communities, as well as do technical, environmental and engineering studies, according to a statement.

A final decision on whether a new station will be built is still "several years out", Bruce Power Executive Vice President James Scongack told Reuters in a recent interview.

"We're really focused on that impact assessment, which we know is at least a three- to four-year process," Scongack said.

($1 = 1.3573 Canadian dollars)

(Reporting by Steve Scherer; editing by Jonathan Oatis)

By Steve Scherer