Deep Geological Repositories

Deep geological repositories

A geological repository is constructed underground, usually at a depth of several hundred metres or more below the surface in a stable rock formation. There are two separate long-term radioactive waste management initiatives underway in Canada that may result in geological repositories.

  • The NWMO APM initiative seeks to find a solution for the long-term management of used nuclear fuel – a solution that is socially acceptable, technically sound, environmentally responsible and economically feasible to Canadians.
  • The Ontario Power Generation (OPG) Deep Geologic Repository (DGR) focuses on the disposal of low- and intermediate-level radioactive wastes at the Bruce Site in Tiverton, Ontario. The DGR will also hold waste produced from the continued operation of the Bruce, Pickering and Darlington nuclear power plants.

Licensing of geological repositories

As Canada's nuclear regulator, the CNSC is responsible for licensing geological repositories intended to provide long-term management of radioactive waste.

The CNSC uses a comprehensive licensing system that covers the entire lifecycle of a geological repository – from site preparation to construction and operation, to decommissioning  (closure and post-closure) and, finally, abandonment (release from CNSC licensing). This approach requires a separate licence at each phase, although the site preparation and site construction licences can be combined.

The CNSC's regulatory oversight of radioactive waste stems from the Nuclear Safety and Control Act (NSCA) and is articulated in CNSC documents P-299, Regulatory Fundamentals, P-290, Managing Radioactive Waste, and G-320, Assessing the Long Term Safety of Radioactive Waste Management. The CNSC also considers international guidance from the International Atomic Energy Agency.

The CNSC can make a licensing decision on a geological repository only after the completion of an environmental assessment (EA). EAs are used to predict, evaluate and manage the environmental impacts of a proposed project, and to determine whether these impacts can be mitigated. EAs examine elements such as air quality, long-term environmental impacts, human health, use of land and resources, as well as Aboriginal interest, physical and cultural heritage.

In a licence application, an applicant must include information associated with a facility's operation and future decommissioning, including financial guarantees for each phase. Financial guarantees ensure the licensees have sufficient funds to cover the cost of decommissioning work resulting from the licensed activity. The outcome of the licensing process feeds back into a compliance program that verifies that the licensee fulfills the regulatory requirements.

Independent research

Since 1978, the CNSC has been involved in independent research and assessment, including international collaboration, on the safe long-term management of used nuclear fuel in geological repositories.

Read about the CNSC's research on geological repositories.

International deep geological repositories

Deep geological repositories are being considered in countries around the world including the United States, Finland, France, Sweden, and the United Kingdom for the long-term management of their high-level radioactive wastes. The only operating deep geological repository is in the US at the WIPP; however, this is for the long-term management of a different type of radioactive waste resulting from their defence program. Nuclear regulators in these countries, including the CNSC, share information and best practices to ensure the safe long-term management of radioactive waste in geological repositories.

Read about the CNSC’s participation in international projects

Additional resources