Small modular reactors

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Nuclear reactors of varying sizes and power outputs are used in Canada for a range of applications, such as research, materials testing, medical uses and electrical power generation. The CNSC regulates activities associated with all of these applications.

In recent years, novel reactor technologies have emerged to potentially supply power to smaller electrical grids or to remote, off-grid areas. These novel technologies are commonly referred to as small modular reactors (SMRs). Although they vary in size, SMRs are typically smaller than traditional nuclear power plants.

SMRs are viewed by many stakeholders and the industry as a potential way forward for nuclear power, as well as a source of clean energy.

As Canada's nuclear regulator, the CNSC does not promote the use of such technologies. However, it is the CNSC’s role to ensure that it is ready to regulate SMR projects in order to protect the health and safety of Canadians and the environment. Our regulation also ensures national security and that we are implementing the international obligations to which Canada has agreed.

What is a small modular reactor?

Learn more about small modular reactors and how they’re changing how the world thinks about nuclear power.


What is a small modular reactor?

Small modular reactors, or SMRs, use fission to create heat that generates energy like traditional nuclear reactors.

They’re designed to be smaller than a traditional reactor.

They vary in size and the power they produce.

What about regulation?

The CNSC has been providing feedback to companies for several years through the pre-licensing vendor design review process.

Big or small and no matter the technology, the CNSC’s role is to regulate the nuclear industry and protect the health and safety of the public and the environment.

Canadian Nuclear Safety Commission

Government of Canada

About SMRs

The term SMR refers to a nuclear reactor facility that is usually smaller than a traditional nuclear power plant, and that may employ multiple novel technological approaches, such as passive/inherent safety features, and extensive use of factory-built modules. Common terms used internationally to describe these designs include advanced reactor technologies and advanced modular reactors.

SMRs can vary significantly in size, design features and cooling types. Examples of different SMR technologies include:

  • integral pressurized water reactors
  • molten salt reactors
  • high-temperature gas reactors
  • liquid metal cooled reactors
  • solid state or heat pipe reactors

SMRs can also be located on sites that differ from those of traditional nuclear power plants. For example, SMRs may be established on small grids where power generation needs are usually less than 300 megawatt electric (MWe) per facility, or at edge-of-grid or off-grid locations where power needs are small – in the range of 2 to 30 MWe.

Electrical utilities, industry groups and government agencies throughout the world are investigating alternative uses for SMRs beyond electricity generation. These include producing steam supplies for industrial applications and district heating systems, and making value-added products such as hydrogen fuel and desalinated drinking water.

How will the CNSC regulate SMRs?

The Canadian nuclear regulatory framework is comprehensive and in large part technology neutral, which means that that it allows for all types of technologies to be safely regulated.

All reactor facilities, including SMRs, are classified as Class IA nuclear facilities under the Class I Nuclear Facilities Regulations. Reactor facilities include:

  • nuclear power plants or small reactors for the generation of power or heat for industrial processes
  • small reactors for non-power generation uses (e.g., isotope production, and research and development activities)

This means that in regulating SMRs, the CNSC can apply the same criteria used to regulate traditional reactor facilities. This will be done through a risk-informed approach, by applying resources and regulatory oversight commensurate with the risk associated with the regulated activity.

As the CNSC continues to prepare for the regulation of SMRs, it is committed to informing Canadians and potential licensees about any changes, applications and notable updates.

CNSC vendor design reviews

A vendor design review (VDR) is an optional service provided by the CNSC at the vendor’s request. A VDR does not result in any decision by the Commission under the Nuclear Safety and Control Act. However, it allows a reactor vendor to receive preliminary CNSC staff feedback on a reactor technology.

This includes:

  • whether the applicant is addressing Canadian regulatory requirements in its design and safety analysis activities
  • whether the applicant is developing the necessary evidence to support the adequacy of the proposed design.

The CNSC is currently engaged in many pre-licensing vendor design reviews for SMRs. For more information on this process and a list of current VDRs visit the CNSC’s VDR page.

Regulatory documents and key information

Proposed SMR projects in Canada

Reports and publications

Additional resources

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