Commission renews Ontario Power Generation Inc.’s power reactor operating licence for its Darlington Nuclear Generating Station

September 25, 2025 – Ottawa

Today, the Canadian Nuclear Safety Commission (CNSC) announced the independent Commission’s decision to renew Ontario Power Generation Inc.’s (OPG’s) power reactor operating licence for its Darlington Nuclear Generating Station for a period of 20 years. The Darlington facility is located in the Municipality of Clarington, Ontario, on the traditional lands and waters of the Michi Saagiig Anishinaabeg, the Gunshot Treaty (1787–88), the Williams Treaties (1923), and the Williams Treaties Settlement Agreement (2018).

In making its decision, the Commission considered submissions from OPG, CNSC staff and 79 intervenors during a 2-part public hearing. The Commission concluded that OPG remains qualified to carry on the activities that the renewed licence will authorize. There are no changes to OPG’s licensed activities under the renewed licence. 

The decision includes a requirement for OPG to provide 2 comprehensive performance updates to the Commission on the conduct of its licensed activities. It also includes a new licence condition that requires OPG to continue its engagement with Indigenous Nations and communities throughout the licence period.

The record of decision is available upon request to the Commission Registry at interventions@cnsc-ccsn.gc.ca. The decision will also be posted in both official languages on the CNSC website at cnsc-ccsn.gc.ca at a later date. All submissions related to this licence renewal are available on the CNSC website.

The CNSC regulates the use of nuclear energy and materials to protect health, safety, security and the environment; to implement Canada’s international commitments on the peaceful use of nuclear energy; and to disseminate objective scientific, technical and regulatory information to the public. The Commission is a quasi-judicial administrative tribunal set up at arm’s length from government, independent from any political, government or private sector influence.

Quick facts

• The Darlington Nuclear Generating Station is made up of 4 CANDU units, with a total output of 3,512 MW.
• Units 1, 2 and 3 are currently operating and refurbished. Unit 4 is under refurbishment.
• The CNSC monitors all nuclear licensees for regulatory compliance to ensure the safety of workers, the public and the environment.

Contact

Media Relations 

Canadian Nuclear Safety Commission 
Tel: 613-996-6860

Email: media@cnsc-ccsn.gc.ca