The DNNP, a proposed project from Ontario Power Generation (OPG), represents the site preparation, construction, operation, decommissioning and abandonment of up to 4 new nuclear reactors at the existing Darlington 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.
In December 2021, OPG announced its selection of 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 one BWRX-300 reactor for this project.
The licensee: Ontario Power Generation
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, support facilities and offices. It would also be the location of the proposed DNNP.
It is located in the Municipality of Clarington, Ontario, on the traditional territory of the Wendat, Anishinabek Nation, and the territory covered by the Williams Treaties with the Michi Saagiig and Chippewa Nations.
DNNP environmental assessment
An environmental assessment (EA) is a planning tool used to ensure that projects are considered in a careful and precautionary manner in order to prevent or mitigate possible environmental effects and to enable decision makers to take actions that promote sustainable development. An EA is carried out prior to any licence being granted and considers the entire lifecycle of a project.
The DNNP was subject to an EA conducted by a joint review panel (JRP) under the Canadian Environmental Assessment Act (CEAA 1992). The JRP conducted an extensive public hearing from March 21, 2011 to April 8, 2011 in the Municipality of Clarington, Ontario for this EA. As Ontario had not chosen a specific reactor technology for the DNNP at the time of the EA, OPG used a plant parameter envelope (PPE) to encompass the range of reactor technologies under consideration and provide a bounding envelope of plant design and site parameter values from the multiple technologies to describe the bounding features of the project.
In its August 2011 EA report, the JRP concluded that, "the Project is not likely to cause significant adverse environmental effects, provided the mitigation measures proposed and commitments made by OPG during the review, and the Panel's recommendations are implemented."
Therefore, before considering OPG's application for a licence to construct a reactor for the DNNP, the Commission was first required to determine whether the chosen technology was fundamentally different from the technologies assessed in the EA for the DNNP and whether a new EA was required.
Matters for decision
The Commission needed to make the following determinations on the applicability of the DNNP EA with respect to OPG's selected technology:
- whether Ontario Power Generation Inc.'s selected reactor technology, the General Electric Hitachi BWRX-300 reactor, is fundamentally different from the reactor technologies assessed in the EA for the DNNP
- whether a new EA is required
These decisions engaged the CNSC, as an agent of the Crown contemplating decisions with the potential to impact asserted or established Aboriginal rights, to respect the duty to consult and, where appropriate, to accommodate Indigenous rights under section 35 of the Constitution Act, 1982. Prior to making its decisions, the Commission had to determine if this duty had been met.
Commission decisions
As described in detail in its decision, the Commission is satisfied that the honour of the Crown has been upheld and that the legal obligation to consult and, where appropriate, accommodate Indigenous interests has been satisfied relative to the Commission's considerations related to the applicability of the EA and plant parameter envelope (PPE) to OPG's BWRX-300 chosen reactor technology. The Commission's decision reflects instructions and expectations set for OPG and for CNSC staff.
The Commission further concluded that:
- Ontario Power Generation Inc.'s selected reactor technology, the General Electric Hitachi BWRX-300 reactor, is not fundamentally different from the reactor technologies assessed in the environmental assessment for the Darlington New Nuclear Project
- a new environmental assessment is not required
Building trust and advancing reconciliation
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, collaboratively drafting rights impacts assessments with Indigenous Nations and communities, and consulting on mitigation measures to help minimize any potential impacts of the DNNP.
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 the Commission member documents that detail CNSC staff's review of the proposed DNNP.
Determination on the applicability of the DNNP EA with respect to OPG's selected technology
In determining whether the BWRX-300 reactor technology is fundamentally different from those assessed in the EA, the Commission evaluated the characteristics of the chosen reactor technology with respect to the technologies assessed in the EA, and whether and how the predictions of the DNNP EA apply to the BWRX-300. The Commission considered:
- written submissions and an oral presentation from OPG, including OPG's review of the BWRX-300 against the environmental impact statement (EIS) for the EA and OPG's review of the BWRX-300 against the PPE for the EA
- written submissions and an oral presentation from CNSC staff
- written and oral submissions from 40 intervenors
The Commission concluded that the BWRX-300 reactor design is not fundamentally different from the reactor technologies assessed in the EA. The Commission found that:
- the BWRX-300 reactor technology is based on the design of previous GE Hitachi boiling water reactors and uses light water as the coolant and moderator, similar to the pressurized water reactor assessed in the EA
- the BWRX-300 reactor fuel is similar in enrichment and characteristics to the pressurized water reactor fuel assessed in the EA
- the physical design of the reactor core and the means of shutting down the nuclear reaction are similar to the pressurized water reactor assessed in he EA
- of the 198 PPE parameters, 60 no longer apply based on the choice of the reactor technology, 130 are within the bounds of the PPE, and 8 are outside the bounds of the PPE but bounded by the conclusions of the EA
The Commission also concluded that a new EA is not required. The Commission found that the conclusions of the EA are bounding to OPG's selected BWRX-300 reactor technology, considering the implementation of proposed mitigation measures and the EA follow-up monitoring program.
The Commission's decision does not authorize the construction of a BWRX-300 reactor for the DNNP. Authorization to construct a reactor would be subject to a future Commission licensing hearing and decision.
Timeline
- In September 2006, OPG applied for a licence to prepare a site for the DNNP
- In May 2007, the CNSC began the EA for the DNNP
- In March 2008, the federal Minister of the Environment referred the EA to a JRP
- On August 25, 2011, the JRP submitted its EA report to the Minister of the Environment, concluding that, "the Project is not likely to cause significant adverse environmental effects, provided the mitigation measures proposed and commitments made by OPG during the review, and the Panel's recommendations are implemented."
- On May 2, 2012, the Government of Canada responded to the EA report, accepting or "accepting the intent" of all of the JRP's recommendations
- On August 17, 2012, the JRP, as a panel of the Commission, issued OPG a 10-year site preparation licence for the DNNP
- On October 12, 2021, the Commission renewed OPG's licence to prepare site
- In December 2021, OPG announced its selection of the General Electric Hitachi BWRX-300 small modular reactor technology for deployment at the DNNP site
- In October 2022, OPG applied for a licence to construct one BWRX-300 reactor
- On April 3, 2023, the Commission announced that it would hold a public hearing to consider and decide on the applicability of the DNNP EA with respect to OPG's selected BWRX-300, as per the Government of Canada's response to Recommendation #1 of the JRP's EA report.
- From January 23 to 25, 2024, the Commission held a public hearing on the applicability of the DNNP EA with respect to OPG's selected technology
