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 currently holds a 10-year operating licence for the Darlington NGS, which expires on November 30, 2025.
OPG also operates a nuclear waste management facility at the station through a waste facility operating licence.
The CNSC has full-time staff onsite who perform inspections to evaluate operations and to verify compliance with regulatory requirements and licence conditions.

Photo courtesy of Ontario Power Generation
Location: | Clarington, Ontario |
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Licensee: | 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: | Units 4 and 2: Operating Units 1 and 3: Refurbishment |
Licence issued: | January 1, 2016 |
Licence expires: | November 30, 2025 |
Start of commercial operation: | Between 1990 and 1993 |
Licensing documentation: | Request a copy of Darlington Nuclear Generating Station licence and licence conditions handbook by email at cnsc.info.ccsn@cnsc-ccsn.gc.ca |
Facility website: | Ontario Power Generation |
Latest news
Commission proceedings
The Commission is an independent administrative tribunal set up at arm’s length from government, without ties to the nuclear industry. Use the links below to find documents related to Commission meetings or hearings.
- July 8, 2023: Fourth regulatory hold point lifted for Darlington Nuclear Generating Station Unit 3
- June 19, 2023: Third regulatory hold point lifted for Darlington Nuclear Generating Station Unit 3
- May 20, 2023: Second regulatory hold point lifted for Darlington Nuclear Generating Station Unit 3
- November 28, 2022: First regulatory hold point lifted for Darlington Nuclear Generating Station Unit 3
- July 21, 2022: Notice of Public Hearing and PFP – Ontario Power Generation – Application to renew its Darlington Waste Management Facility operating licence
- June 30, 2022: First regulatory hold point removed for the Darlington molybdenum-99 project
- March 1, 2022: Record of Decision - Ontario Power Generation - Request for Authorization to Restart Darlington Nuclear Generating Station Units 1 and 4 following future outages
- January 4, 2022: Record of Decision - Ontario Power Generation - Application to Amend Power Reactor Operating Licence PROL 13.02/2025 to Authorize the Production of Molybdenum-99 at the Darlington Nuclear Generating Station
- November 24, 2021: Record of Decision - Bruce Power and Ontario Power Generation - Review by the Commission of 3 Designated Officer Orders Issued to Bruce Power and Ontario Power Generation Inc. on July 26-27, 2021; and Requests to Restart Reactors subject to the Orders
- November 9, 2021: CNSC amends Ontario Power Generation’s power reactor operating licence for its Darlington Nuclear Generating Station to authorize the production of Molybdenum-99
Regulatory actions
The CNSC posts regulatory enforcement actions taken to protect the health, safety and security of Canadians and the environment. Use the links below to find out more about any orders or penalties that have been placed on this licensee, if any.
- May 31, 2023: Administrative monetary penalty issued
Disclosure
Licensees must report events and incidents involving licensed activities that could impact the health, safety and security of Canadians and the environment to the CNSC. Use the links below to find any information provided by this licensee, if any, as well as other public disclosures made by licensees.
- Event reports
(source: Ontario Power Generation) - Disclosure protocol
(source: Ontario Power Generation)
Engagement
- September 16-18, 2022: CNSC participated in Community Outreach at the Port Hope Fair
- September 23-24, 2022: CNSC participated in OPG Community Open House at the Darlington Energy Complex.
- October 12, 2022: CNSC participated in engagement meetings with Hiawatha First Nation Leadership
- October 13, 2022: CNSC participated in engagement meetings with Mississaugas of Scugog Island First Nation Leadership
- October 14, 2022: CNSC participated in engagement meetings with Curve Lake First Nation Leadership
Related links
Protecting Canadians and the environment
Environment
The CNSC uses information provided by licensees to create our own reports assessing the environmental effects of nuclear facilities or licensed activities.
- Environmental monitoring: Independent environmental monitoring results collected by the CNSC
- Environmental risk assessment: Email cnsc.info.ccsn@cnsc-ccsn.gc.ca to request a copy
- Federal, provincial and municipal monitoring programs: List of monitoring programs managed by other levels of government
- Radionuclide releases: Nuclear Power Plants dataset in the Open Government catalogue for information on releases from this facility
Health and safety
The CNSC oversees licensee emergency planning and works with other levels of government to ensure the health and safety of Canadians. We also conduct and review health studies on various areas associated with the production, possession or use of nuclear substances.
- Emergency Management Ontario
- OPG nuclear safety and emergency preparedness
- CNSC health studies on Canadian nuclear facilities: Relevant health studies of nuclear reactors regulated by the CNSC
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