Our nuclear operating licences

Status: The Darlington Nuclear Generating Station (DNGS) is nearing completion of its multi-year refurbishment to safely extend operations and holds a 20-year operating licence.

Licence valid from:  Dec.1, 2025 to Nov. 30, 2045

Updates: 

The CNSC will conduct a hearing in writing in summer 2026 to consider OPG's application to change the Integrated Implementation Plan (IIP) for the Darlington Nuclear Generating Station.

The IIP includes actions from the environmental assessment and the integrated safety review that OPG completed in support of the refurbishment and continued operation of the Darlington NGS. OPG is proposing to expand the scope and extend the timelines of 2 IIP items – the aquatic thermal study and the aquatic impingement and entrainment study – and to add a task to the latter for a study on best available technology economically achievable. Requests to intervene must be filed with the Commission Registry by June 30, 2026. For more information, refer to the CNSC's Notice of Hearing or visit www.cnsc-ccsn.gc.ca.

Darlington licence renewal

On Sept. 25, 2025, the CNSC announced its decision to renew OPG’s licence for the DNGS for a 20-year term. This decision authorizes OPG to operate the Darlington station from Dec. 1, 2025 to Nov. 30, 2045, making it the longest nuclear operating licence granted in Canada. 

For more information on the licence renewal process, visit the CNSC webpage at www.cnsc-ccsn.gc.ca.

Nuclear isotopes

OPG has received licence amendments from the CNSC that authorize the production of Molybdenum-99 (Mo-99), Lutetium-177 (Lu-177), Yttrium (Y-90), and Cobalt-60 (Co-60) in all four units at the Darlington Nuclear Generating Station.

• Summary Record of Decision – Application to Amend the Licensing Basis for the Darlington Nuclear Generating Station to Install and Operate a Target Delivery System on Additional Units (PDF)
• Record of Decision – Application to Amend Darlington Power Reactor Operating Licence for Lutetium-177 and Ytrium-90 (PDF)
• Record of Decision – Application to Amend Darlington Power Reactor Operating Licence for Cobalt-60 (PDF)
• Record of Decision – Application to Amend Darlington Power Reactor Operating Licence for Molybdenum-99 (PDF)

Learn more about the power of nuclear isotopes.

Status: Units 5 to 8 are licensed to operate to Dec. 31, 2026, up to a maximum of 305,000 equivalent full power hours. Unit 1 was removed from service in October 2024. Unit 4 was removed from service in December 2024. Units 2 and 3 remain in safe storage.  

Licence valid from: Sept. 1, 2018 to Aug. 31, 2028 

Update:  On June 30, 2025, OPG submitted an early application to the Canadian Nuclear Safety Commission (CNSC) requesting renewal of the Pickering Nuclear Generating Station’s Power Reactor Operating Licence (PROL) for a 10-year term from Jan. 1, 2027 to Dec. 31, 2036. During this term, OPG plans to refurbish Units 5 to 8 to support continued operations for 30-plus years and progress the decommissioning of Units 1 to 4 as per the CNSC approved Detailed Decommissioning Plan (DDP). Additionally, this application requests the consolidation of the licensed activities authorized under the current Pickering Waste Facility Operating Licence (WFOL) with the Pickering PROL to give a holistic view of generation and waste for managing the licence, based on feedback from intervenors, and to streamline regulatory processes. The CNSC will hold a 2-part public hearing on June 23, 2026, and the week of Oct. 5, 2026, to consider OPG's application. Refer to the Notice of Hearing for more information, including participant funding and hearing details. 

To support refurbishment, OPG is conducting a comprehensive Periodic Safety Review (PSR3) which includes an assessment of station design and operation against applicable current safety standards and operating practices and ensures a continued high level of safety throughout the station’s operating life. The PSR will be completed before any of the units begin return-to-service post refurbishment. OPG is committed to continuous improvement in safety and the Pickering NGS has robust and comprehensive programs in place aligned with industry best practices for ensuring the condition of Structures, Systems, and Components are well understood and well maintained.

Additional documentation:

• Predictive Environmental Risk Assessment (PERA) for Pickering Refurbishment, Decommissioning, and Continued Operations (PDF). OPG has shared this PERA report (R000) as a draft for review and comment by the Williams Treaties First Nations. However, it does not at this time include the voices of the Nations.
• PNGS Climate Resilience Assessment Summary (PDF)
• OPG Commission Member Document

Previous updates:

• OPG submitted a letter of intent to the CNSC in 2024 stating that an application for the licence renewal of Pickering NGS would be submitted no later than September 2025.
• OPG submitted a Licence Amendment Application and supplementary Commission Member Document to the Canadian Nuclear Safety Commission (CNSC). Following a two-day public hearing in June 2024, OPG was granted authorization to operate Pickering NGS Units 5 to 8 to the end of December 2026, up to a maximum of 305,000 equivalent full power hours. 
• Recorded webcasts of public hearings are available on the CNSC website.
• To read more about our Pickering licences, visit the OPG Document Archive.

Status: The Nuclear Sustainability Services - Western Waste Management Facility (NSS-WWMF) currently holds a ten-year operating licence.

Licence valid from:  June 1, 2017 to May 31, 2027

On Dec. 20, 2025, OPG submitted an application to the Canadian Nuclear Safety Commission (CNSC) requesting renewal of the Western Waste Management Facility’s (WWMF), Waste Facility Operating Licence (WOFL) for a 10-year term from June 1, 2027 to May 31, 2036.

During this term, OPG plans to continue to safely manage, process and store low and intermediate-level waste from OPG’s nuclear generating stations as well as used fuel from Bruce Power operated reactors.

OPG has updated it’s application to the Canadian Nuclear Safety Commission (CNSC) requesting renewal of the Western Waste Management Facility’s (WWMF), Waste Facility Operating Licence (WOFL) for a 10-year term from June 1, 2027 to May 31, 2036. The updated application includes the removal of proposed storage buildings 9 and 10.

During this term, OPG plans to continue to safely manage, process and store low and intermediate-level waste from OPG’s nuclear generating stations as well as used fuel from Bruce Power operated reactors.

OPG’s application is to renew the existing facility licence, with no changes to the licenced activities, for a period of 10 years.

The CNSC has issued a notice of public hearing to consider OPG’s licence renewal application the week of Feb. 22, 2027, with a time and location to be determined. The CNSC will make available Participant Funding prior to the hearing through its Participant Funding Program. The deadline for submitting a completed participant funding application form to the CNSC is June 16, 2026.

Persons who have an interest or expertise in relation to the re-licencing of a nuclear facility whose input may be useful to the Commission’s decision on the application, may provide comments. Requests to intervene must be filed with the Commission Registry by Jan. 11, 2027 using the CNSC’s online request form, e-mailing the Registry at [email protected] or using the contact information found on the CNSC website.

Additional pertinent dates and related documents will continue to be shared as they become available.

To read more about our current NSS Western Facility licence, visit the OPG Document Archive.

Status: The Nuclear Sustainability Services - Darlington Waste Management Facility (NSS-DWMF) currently holds a ten-year operating licence.

Licence valid from: May 1, 2023 to April 30, 2033 

Related documents:

• Letter of Intent Submitted to CNSC (PDF)
• Application to CNSC for 10-Year Licence (PDF)
• Safety Assessment Summary Report (PDF)
• OPG Commission Member Document for the DWMF Licence Renewal Hearing - Jan. 26, 2023 (PDF)
• Commission’s Record of Decision for the DWMF Licence Renewal Hearing – Jan 26, 2023 (PDF)

Status: The Nuclear Sustainability Services - Pickering Waste Management Facility (NSS-PWMF) currently holds a ten-year operating licence.

Licence valid from:  Apr. 1, 2018 to Aug. 31, 2028

Updates:

Pickering Component Storage Structure (PCSS):
The CNSC has approved the construction of the Pickering Component Storage Structure on site at the Pickering NGS. The PCSS will provide interim storage capacity, intended for radioactive component waste/material. It will be required to support the refurbishment of Pickering NGS Units 5 through 8 and future Pickering NGS decommissioning activities. Read the attached Record of Decision or visit the CNSC website for more information.

OPG has submitted an application to the CNSC to renew the Power Reactor Operating Licence (PROL) for the Pickering NGS for a 10-year term, from Jan. 1, 2027 to Dec. 31, 2036. This application includes the request to undertake the planned refurbishment of Units 5 to 8 to continue operation for 30-plus years, to progress the decommissioning of Units 1 to 4 as per the CNSC approved Detailed Decommissioning Plan (DDP), and to consolidate the licensed activities currently authorized under the Pickering Waste Facility Operating Licence (WFOL) with those under the Pickering NGS PROL to streamline regulatory processes. Refer to the Notice of Hearing for more information, including participant funding and hearing details. 

To read more about our NSS-PWMF licence, visit the OPG Document Archive.

Status: Ontario Power Generation (OPG) applied to the Canadian Nuclear Safety Commission (CNSC) for a Licence to Operate (LTO) its first Small Modular Reactor (SMR) unit for the Darlington New Nuclear Project (DNNP), in March 2026.

Licence valid from: 20-year licence term requested

Update: The DNNP has completed site preparation activities and commenced construction activities on the first SMR unit, as well as on common infrastructure, under the project’s existing Licence to Prepare Site (valid through October 11, 2031) and Licence to Construct (valid through March 31, 2035).

In March 2026, OPG applied to the CNSC for a Licence to Operate the first SMR and a low and intermediate-level waste storage structure at the Darlington New Nuclear site. The LTO is the regulatory approval required to complete commissioning and safely operate the reactor, once construction is complete.

The CNSC will initiate a public engagement program associated with the LTO application, including consultation activities and a public hearing with interventions, likely in 2027. Visit cnsc-ccns.gc.ca for more information on the hearing process.