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How environmental assessments work

Types of environmental reviews

The CNSC reviews all nuclear projects carefully to determine their effects on the environment and on the people living or working in nearby communities. Depending on the location of the project and its design, it may be subject to different types of assessments:

  • impact assessments
  • federal lands reviews
  • federal environmental assessments
  • environmental assessments under provincial regimes and land claim agreements
  • environmental protection reviews

Impact assessments

In 2019, the Government of Canada passed the Impact Assessment Act (IAA). The IAA requires that federal assessments take into account the environmental, health, social and economic effects, both positive and negative, of a proposed project. Impact assessments are conducted on projects identified as having the greatest potential for adverse environmental effects in areas of federal jurisdiction, as set out in the Physical Activities Regulations.

The Impact Assessment Agency of Canada (IAAC) leads the reviews of major projects and works in collaboration with the CNSC to review any projects that are also subject to regulation under the Nuclear Safety and Control Act (NSCA).

The CNSC has a memorandum of understanding with the IAAC that outlines the collaboration between the 2 partners in conducting integrated impact assessments under the IAA.

To learn more, view a presentation about impact assessments and the role of the CNSC.

Federal lands reviews

Projects not listed in the Physical Activities Regulations but proposed to be carried out on federal lands and requiring a decision by the CNSC as a federal authority are subject to federal lands reviews under the IAA.

This includes the projects and facilities run by Atomic Energy of Canada Limited, such as the Port Hope Area Initiative and Chalk River Laboratories, which are regulated by the CNSC and located on federal lands. The Royal Military College of Canada SLOWPOKE-2 Research Reactor is also located on federal lands managed by the Department of National Defence.

If the CNSC receives a licence application for proposed activities on federal lands, CNSC staff will review the proposal and determine whether it is subject to a federal lands review under the IAA.

Where proposed projects are subject to the federal lands provisions of the IAA, the Commission, in accordance with section 82 of the act, must determine whether the completion of the proposed project on federal lands is likely to cause significant adverse environmental effects. The factors that the CNSC must consider are set out in section 84 of the IAA. The IAAC is developing further guidance and materials on federal lands reviews in collaboration with federal authorities, including the CNSC.

Federal environmental assessments

The CNSC is currently conducting environmental assessments for several nuclear projects following the process established under the Canadian Environmental Assessment Act, 2012 (CEAA 2012). The graphic below identifies the steps involved in reviewing the potential environmental impacts of nuclear projects under CEAA 2012. See the environmental assessments page for more information.

Figure 1: Public engagement and Indigenous consultation
EAP, public engagement and Indigenous consultation. Text version below.
Figure 1 - Text version

Public engagement and Indigenous consultation

Ongoing public engagement and Indigenous consultation throughout the environmental assessment process.

  1. Environmental assessment determination
    • Early engagement
    • Proponent submits project description
    • CNSC accepts project description or
    • Requests more information
    • CNSC determines whether an environmental assessment is required
    • CNSC issues notice of commencement
  2. Project description
    • Comment period on project description (formal participation opportunity)
    • Commission decision on scope of environmental assessment
    • Participant Funding Program available
  3. Environmental impact statement and technical review
    • Proponent submits environmental impact statement
    • Technical review of environmental impact statement
    • Comment period on environmental impact statement (formal participation opportunity)
    • CNSC requests more information as needed until complete
  4. Environmental assessment report
    • CNSC drafts environmental assessment report
    • Environmental assessment report provides recommendations to the Commission
    • Environmental assessment report posted for public review and comment through Commission hearing interventions (formal participation opportunity)
  5. Hearing and decision
    • Commission holds public hearing with interventions (formal participation opportunity)
    • Environmental assessment decision by the Commission is published, including detailed reasons
    • PFP available
  6. Ongoing oversight, monitoring and compliance
    • Compliance verification activities
    • Reviews of environmental monitoring and follow-up reports
    • Reports to the Commission on the status of ongoing monitoring and compliance throughout the lifecycle

Environmental assessments under provincial regimes and land claim agreements

Proposed nuclear projects may be subject to provincial environmental assessment (EA) legislation but not the IAA. In addition, in many parts of northern Canada, such as Yukon, Northwest Territories, Nunavut, parts of Quebec, and parts of Newfoundland and Labrador, EA processes established under land claim agreements apply while the IAA does not.

In such cases, the CNSC acts as a technical advisor throughout the EA process but has no role in the EA decision. However, the Commission retains decision-making authority on licensing matters and uses the information gathered in the EA process to inform its licensing decisions under the NSCA.

Learn about the Commission process.

Environmental protection reviews

An environmental protection review is a science-based technical assessment conducted by CNSC staff, as required by the NSCA. See the environmental protection reviews page for more information.

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