Darlington Nuclear Generating Station


Ontario Power Generation (OPG) owns and is licensed to operate the Darlington Nuclear Generating Station, located in the municipality of Clarington, on the north shore of Lake Ontario. OPG also operates a nuclear waste management facility at the station. The CNSC has full-time staff onsite who perform inspections to evaluate operations and to verify compliance with regulatory requirements and licence conditions.


Plant Information

Location: Clarington, Ontario
Operator: Ontario Power Generation
Reactor type: CANDU (CANada Deuterium Uranium)
Vendor: Atomic Energy of Canada Limited
Number of units: 4 reactors
Installed capacity: 3,512 MW
Status: All four reactors operating
Licence issued: January 1, 2016
Licence expires: November 30, 2025
Start of commercial operation: Between 1990 and 1993
Refurbishment: Planned (Environmental Assessment completed, Integrated Safety Review in progress)
Licensing documentation: Request a copy of the Darlington NGS licence and licence condition handbook by email

Aerial view of the Darlington Nuclear Generating Station

Latest CNSC Plant-Specific Announcements

Latest Licensee Public Disclosures

As part of CNSC's regulatory requirements, major licensees must have robust public information and disclosure programs in place. These programs, for nuclear power plants, include a disclosure protocol developed in consultation with community stakeholders. You may visit OPG's Web site for all public site updates triggered by the protocol's disclosure criteria.


A CNSC Inspector checks a service building that houses the pumps that draw cooling water from Lake Ontario at the Darlington Nuclear Generating Station.

Adjacent Nuclear Facility and Project

Tritium removal facility

The Darlington site includes a Tritium Removal Facility (TRF) designed to minimize the amount of tritium going into the environment, as well as reducing the potential radiation exposure of workers. The TRF extracts tritium from the heavy water used in the reactors. The extracted tritium is then safely stored in stainless steel containers within a concrete vault.

Ontario Power Generation Darlington new nuclear power plant project

The Darlington project is for the site preparation, construction, operation, decommissioning and abandonment of up to four new nuclear reactors at the existing Darlington Site to generate approximately 4,800 megawatts of electricity to the Ontario grid.

Find out more about the status of this project.