Darlington New Nuclear Project
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Current status: One unit under construction
The Darlington New Nuclear Project (DNNP) is a proposed nuclear facility at the existing Darlington site in the Municipality of Clarington. The DNNP includes the site preparation, construction and operation of up to 4 new nuclear reactors. The site is owned by Ontario Power Generation (OPG).
OPG announced its selection of the GE Vernova Hitachi BWRX-300 reactor for deployment at the DNNP site in December 2021. The BWRX-300 is a 300 MWe water-cooled, natural circulation small modular reactor. OPG applied for a licence to construct a BWRX-300 reactor in October 2022 and was granted the licence in April 2025.
In April of 2025, the Commission issued OPG a licence to construct 1 BWRX-300 reactor at the DNNP site. That licence includes 3 regulatory hold points (RHPs). The commitments OPG has made in relation to each hold point must be completed before that hold point is removed.
The CNSC has verified that the commitments for RHP-1 (for installation of the reactor building foundation) were met, and the hold point was removed on March 30, 2026. Learn more about regulatory hold points for new reactor facilities.
In March 2026, OPG applied for a 20-year licence to operate 1 BWRX-300 reactor and an associated low- and intermediate-level waste storage structure at the DNNP site. The application for a licence to operate is subject to a decision by the Commission following a public hearing, to be announced at a later date.
Facility information
| Location | Bowmanville, Municipality of Clarington, Ontario |
|---|---|
| Licensee | Ontario Power Generation (OPG) |
| Reactor type | BWRX-300 |
| Number of units | Applied for 1 unit construction, with possibility of a future application for up to 3 additional units of construction |
| Status |
Holds a licence to prepare site (valid until 2031) Holds a licence to construct (valid until March 31, 2035) |
| Licensing documentation | Request a copy of OPG’s licence documentation by email at cnsc.info.ccsn@cnsc-ccsn.gc.ca |
| Project information and reports | Open Government portal – Darlington New Nuclear Project – information and reports |
| Joint Review Panel decision history | Joint review panel (JRP): Darlington new nuclear power plant – Canadian Nuclear Safety Commission |
| Facility website | Darlington New Nuclear Project |
| Timelines | Darlington New Nuclear Project timeline |
Related news
Commission proceedings
The Commission is an independent administrative tribunal set up at arm’s length from government. It does not have ties to the nuclear industry. Use the following links to find documents related to Commission meetings or hearings:
- March 30, 2026: First regulatory hold point lifted for the Darlington New Nuclear Project
- April 4, 2025: (News release) Commission authorizes Ontario Power Generation Inc. to construct 1 BWRX-300 reactor at the Darlington New Nuclear Project site
- December 3, 2024: Revised notice of public hearing – Ontario Power Generation – Application for a licence to construct 1 BWRX-300 reactor for its Darlington New Nuclear Project (PDF, 133 KB)
- June 27, 2024: Notice of Public Hearing – Ontario Power Generation – Application for a licence to construct one BWRX-300 reactor for its Darlington New Nuclear Project (PDF, 273 KB)
- April 22, 2024: (News release) Independent Commission determines environmental assessment for Ontario Power Generation’s Darlington New Nuclear Project is applicable to the selected reactor technology
- January 29, 2024: Archived webcast of the public hearing, January 23–25, 2024
- April 3, 2023: CNSC to conduct a public hearing on applicability of the Darlington New Nuclear Project environmental assessment and plant parameter envelope to selected reactor technology (PDF, 130 KB)
- June 7, 2022: Record of Decision – Ontario Power Generation – Application for Acceptance of the Revised Financial Guarantee Proposed by Ontario Power Generation for its Darlington New Nuclear Project (Decision) (PDF, 201 KB)
Regulatory actions
The Canadian Nuclear Safety Commission (CNSC) posts regulatory enforcement actions taken to protect the environment and the health, safety and security of all people in Canada. Use the following links to find out more about any orders or penalties that have been issued to this licensee:
- July 25, 2025: Letter to OPG
Disclosure
Licensees must report to the CNSC all events and incidents involving licensed activities that could impact the environment or the health, safety and security of people in Canada. Use the following links to find public disclosures made by this or any other licensee:
Engagement
The CNSC recognizes the importance of engaging and building relationships with the public living near existing or proposed nuclear facilities and with other interested parties.
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July 8, 2024: (Webinar) Update on OPG’s application for a licence to construct for the Darlington New Nuclear Project
- Watch a recording of the webinar (video)
- January 2024: Participant Funding Program decision – Review of Ontario Power Generation’s application for a licence to construct for the Darlington New Nuclear Project
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October 31, 2023: (Webinar) Darlington New Nuclear Project – Regulatory review and public hearing update
- Watch a recording of the webinar (video)
- September 26, 2023: (Open house) Regulatory oversight of nuclear projects in the Municipality of Clarington, Ontario
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June 22, 2023: (Webinar) Darlington New Nuclear Project – Upcoming licensing review
- Watch a recording of the webinar (video)
OPG licence applications
- March 25, 2026: OPG submits an application to the CNSC for a licence to operate 1 BWRX-300 reactor and an associated low- and intermediate-level waste storage structure at the Darlington New Nuclear Project site.
- October 31, 2022: OPG submits an application to the CNSC for a licence to construct a reactor facility for the Darlington New Nuclear Project, along with supporting documentation.
- June 2020: Application for renewal of site preparation licence (PDF, 5 MB)
Contact us for more information
DNNP documents
- Impact Assessment Agency of Canada: Darlington New Nuclear Power Plant Project (Archived)
- Darlington New Nuclear Project: Applicability of the BWRX-300 reactor to the environmental assessment – public summary
- Facility website: See the “Supporting documents and resources” section.
- Darlington New Nuclear Project: Applicability of the BWRX-300 reactor to the environmental assessment – public summary
Protecting the environment and all people in Canada
Environment
The CNSC uses information provided by licensees to create its own reports assessing the environmental effects of nuclear facilities or licensed activities:
- Environmental monitoring: See the 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: See the list of monitoring programs managed by other levels of government
- Radionuclide releases: View the 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 all people in Canada. The CNSC also conducts and reviews various health studies related to the production, possession or use of nuclear substances.
- CNSC health studies on Canadian nuclear facilities: Consult relevant health studies on nuclear reactors regulated by the CNSC
Related links
- Protocols
- March 4, 2024 (Darlington New Nuclear Project): Status of Joint Review Panel recommendations to date
- January 2024: Commission hearing information for January 2024 – Darlington New Nuclear Project
- April 4, 2023: CNSC virtual workshop on OPG’s Plant Parameter Envelope and Environmental Impact Statement review reports – see the Darlington New Nuclear Project (DNNP) workshop summary report, summarizing the event.
- March 15, 2023: (Executive summary) Combined phases 1 and 2 pre-licensing vendor design review – General Electric Hitachi Nuclear Energy
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November 15, 2022: (Webinar) Darlington New Nuclear Project – Upcoming licensing review
- Watch a recording of the webinar (video)
- October 24, 2022: Participant funding to review the environmental impact statement and plant parameter envelope for Ontario Power Generation’s Darlington New Nuclear Project
- March 28, 2022: CNSC to conduct a hearing in writing on the financial guarantee proposed by Ontario Power Generation for its Darlington New Nuclear Project (PDF, 120 KB)
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February 2, 2022: (Webinar) CNSC's role in the regulation of small modular reactors
- Watch a recording of the webinar (video)
- November 24, 2021: Record of Decision - Ontario Power Generation – Application to Renew the Power Reactor Site Preparation Licence for the Darlington New Nuclear Project (PDF, 120 KB)
- June 10, 2021: Hear what our expert said at the Commission hearing on the Darlington New Nuclear Project. Video: Environmental assessment decisions have no shelf life
- March 1, 2021: Revised notice of public hearing on the renewal of Ontario Power Generation Inc.’s nuclear power reactor site preparation licence for the Darlington New Nuclear Project (PDF, 257 KB)
- December 2, 2020: Ontario Power Generation (OPG) submits Notice of Intent for Submission of Licence to Construct Application (PDF, 229 KB)
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