The four Atomic Energy of Canada Ltd., AREVA NP, GE Hitachi Nuclear Energy, and Westinghouse Electric Co. are being asked to show that they can qualify for a construction licence and have the ability of deliver on the massive project.
Atomic Energy is the only Canadian company invited to submit. Its CANDU reactors now supply half of Ontario's electricity and about 16 per cent of Canada's. The deadline for this first part of the two-phase process is May.
In phase two of the process, companies will be asked to submit formal financial and commercial terms, construction timetables, operating and decommissioning costs. They'll also be asked to spell out the benefits of their bids to the domestic economy.
The procurement process will be overseen by the provincial government, Ontario Power Generation and Bruce Power.
A review board and a "fairness monitor" will also be in place to make sure the process is transparent and fair.
Ontario announced a plan in 2006 to ensure a reliable supply of power and reduce its carbon footprint by refurbishing some of its nuclear reactors and building new ones on existing nuclear sites.
A report from the Ontario Power Authority had recommended that the province spend $70 billion to maintain a stable supply of electricity, with more than half the money allocated to nuclear power.
There are 16 operating nuclear reactors in Ontario at the Darlington, Pickering, and Bruce generating stations.