Canadian Nuclear Safety Commission
Ontario Power Gets Nod for Darlington Reactor Build
The Canadian Nuclear Safety Commission (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. It makes decisions with respect to regulating nuclear safety, including licensing decisions, and is also independent of CNSC staff.
Ontario Power Generation Inc. (OPG) is an Ontario government business enterprise that operates the Darlington Nuclear site. The site includes the Darlington Nuclear Generating Station, the Darlington Waste Management Facility, the Darlington New Nuclear Project (DNNP) site, support facilities and offices.
The site is located in the Municipality of Clarington, Ontario, within the traditional lands and waters of the Michi Saagiig Anishinaabeg, the Gunshot Treaty (1877-88), the Williams Treaties (1923), and the Williams Treaties First Nations Settlement Agreement (2018).
The DNNP, a proposed project from OPG, represents the site preparation, construction, operation, decommissioning and abandonment of up to 4 new nuclear reactors at the existing Darlington Nuclear site. The DNNP site is located on the eastern third of the Darlington Nuclear site. The goal of this project is to generate up to 4,800 megawatts of electricity for the Ontario grid. The DNNP would be a Class IA nuclear facility, per section 1 of the Class I Nuclear Facilities Regulations. OPG currently holds a CNSC power reactor site preparation licence for the DNNP.
The DNNP was subject to an environmental assessment (EA) conducted by a joint review panel (JRP) under the Canadian Environmental Assessment Act. The EA was completed in 2012, and the Government of Canada determined that the DNNP was not likely to cause significant adverse environmental effects.
In December 2021, OPG announced that it had selected the General Electric Hitachi BWRX-300 reactor for deployment at the DNNP site. In October 2022, OPG applied to the CNSC for a licence to construct 1 BWRX-300 reactor for this project. In April 2024, the Commission determined that the EA for the DNNP remained applicable to the selected reactor technology.
The Commission considered a licensing decision under paragraphs 24(4)(a) and (b) of the Nuclear Safety and Control Act (NSCA) whether to authorize OPG to construct, and if so, with what terms and conditions.
This decision engaged the CNSC, as an agent of the Crown contemplating decisions with the potential to impact asserted or established Aboriginal rights, to discharge the duty to consult and, where appropriate, to accommodate Aboriginal rights under section 35 of the Constitution Act, 1982. Prior to making its decision, the Commission had to determine if this duty had been met.
As described in detail in its decision, the Commission was satisfied that the honour of the Crown had been upheld and that the legal obligation to consult and, where appropriate, accommodate Indigenous interests had been satisfied relative to the Commission’s licensing decision. The Commission’s decision directs OPG and CNSC staff to implement accommodation measures to further enable the incorporation of Indigenous knowledge and practices into both the conduct of licensed activities and CNSC oversight.
The Commission decided to issue nuclear power reactor construction licence PRCL 32.00/2035 to OPG for the construction of 1 BWRX-300 reactor at the DNNP site. In making its decision, the Commission concluded that OPG is qualified to carry out the activities authorized under the licence to construct; that OPG has adequate programs in place to ensure that the health and safety of workers, the public and the environment will be protected under the licence to construct; and that OPG will make adequate provision for the maintenance of national security and to implement international obligations to which Canada has agreed.
The licence is valid until March 31, 2035, and includes 4 site-specific licence conditions that require OPG to:
As part of its decision, the Commission also accepted OPG’s proposed financial guarantee in the form of a letter of credit in the amount of $167,180,000.
The decision by the Commission does not authorize the operation of a BWRX-300 reactor at the DNNP site. Authorization to operate the reactor would be subject to a future Commission licensing hearing and decision, should OPG come forward with a licence application to do so.
Under the licence, OPG is required to provide additional information to the CNSC prior to undertaking specific construction activities. Commitments that are essential to verify compliance with regulatory requirements related to the safety analysis and design of structures, systems, and components that are important to safety are tied to 3 regulatory hold points (RHP):
As part of its decision, the Commission authorized the CNSC Executive Vice-President and Chief Regulatory Operations Officer, Regulatory Operations Branch to administer licence condition 15.3 with respect to the removal of regulatory hold points.
As Canada’s nuclear regulator, the CNSC is committed to building trust and advancing reconciliation.
As a lifecycle regulator, the CNSC focuses on continuous engagement and consultation with Indigenous Nations and communities before, during and after Commission proceedings for CNSC activities. This includes, for example, sharing project information, encouraging participation in public proceedings, and providing participant funding.
Going forward, the CNSC will continue its work to develop and nurture long-term relationships with the Indigenous Nations and communities that have been, and will continue to be, involved in the regulatory process for the DNNP.
Additional information on the CNSC’s consultations in the context of the DNNP can be found in CNSC staff’s review of the proposed DNNP.
Timeline
https://www.canada.ca/en/nuclear-safety-commission/news/2025/04/decision-by-the-commission-to-authorize-ontario-power-generation-inc-to-construct-1-bwrx-300-reactor-at-the-darlington-new-nuclear-project-site.html