Low- and intermediate-level radioactive waste

In Canada, low- and intermediate-level radioactive waste refers to all forms of radioactive waste, except used nuclear fuel, limited waste from the production of medical isotopes, and the waste from uranium mining and milling.

• Low-level radioactive waste
• Intermediate-level radioactive waste
• Main sources of low- and intermediate-level radioactive waste
• Long-term management of low- and intermediate-level radioactive waste

Low-level radioactive waste

Low-level radioactive waste (LLW) contains material with radionuclide content above the established unconditional clearance levels and exemption quantities (set out in the Nuclear Substances and Radiation Devices Regulations ), but generally has limited amounts of long-lived radionuclides. LLW requires isolation and containment for periods of up to a few hundred years and is suitable for disposal in near surface facilities.

LLW includes the following subclasses:

• Very low-level radioactive waste (VLLW) has a low hazard potential and is above the criteria for unconditional clearance levels and exemption quantities. Long-term waste management facilities for VLLW do not need a high degree of containment or isolation. Concentrations of longer-lived radionuclides in VLLW are generally very limited.
• Very short-lived low-level radioactive waste (VSLLW) is waste that can be stored for a decay period of not more than a few years and subsequently cleared for release. VSLLW includes radioactive waste containing only short half-life radionuclides typically used for research and biomedical purposes. The main criterion for VSLLW is the half-life of the predominant nuclides. In general, the management option of storage for decay for VSLLW should only apply to radionuclides with a half-life of 100 days or less.

LLW includes contaminated equipment from the operation of nuclear power plants (for example, protective shoe covers, clothing, rags, mops, equipment and tools).

The owners of LLW are responsible for managing the waste they produce. This usually takes place onsite, within a facility specifically for the LLW.

LLW that requires long-term management may be returned to the manufacturer or transferred to an authorized waste management operator – such as the waste management facility operated by Canadian Nuclear Laboratories (CNL) at its Chalk River Laboratories – on a fee-for-service basis.

Intermediate-level radioactive waste

Intermediate-level radioactive waste (ILW) generally contains long-lived radionuclides in concentrations that require isolation and containment for periods greater than several hundred years. ILW needs no provision, or only limited provision, for heat dissipation during its storage and disposal. Due to its long-lived radionuclides, ILW generally requires a higher level of containment and isolation than can be provided in near-surface repositories.

ILW includes refurbishment waste, ion-exchange resins and some radioactive sources used in radiation therapy.

The owners of ILW are responsible for managing the waste they produce. This usually takes place onsite, within a facility specifically for the ILW.

ILW that requires long-term management may also be returned to the manufacturer or transferred to an authorized waste management operator – such as the waste management facility operated by Canadian Nuclear Laboratories at its Chalk River Laboratories – on a fee-for-service basis.

Main sources of low- and intermediate-level radioactive waste

As the waste owners, Atomic Energy of Canada Limited (AECL) and Ontario Power Generation (OPG) (which own 20 of Canada’s 22 nuclear power reactors combined) are responsible for approximately 90% and 99% of the annual accumulated volume of low- and intermediate-level radioactive waste (L&ILW), respectively, as of 2019. These accumulation rates represent the waste generated from research and development activities at CNL’s Chalk River Laboratories (including from decommissioning and environmental remediation) and nuclear power production in Ontario, respectively. AECL’s accumulation rate also includes L&ILW for long-term management from a number of smaller producers and users of radioactive material (e.g., hospitals and universities). The other 2 nuclear power reactors (owned by New Brunswick Power [NB Power] and Hydro-Québec [HQ]) and Cameco’s uranium processing and conversion facilities in Ontario generate the majority of the remaining waste. The owners of L&ILW are licensed by the CNSC to manage and operate interim storage facilities for their radioactive waste.

Long-term management of low- and intermediate-level radioactive waste

The CNSC requires facility operators to ensure they have sufficient funds to cover the costs associated with the long-term management of low- and intermediate-level waste.

Canada’s largest radioactive waste owners – AECL, OPG, HQ and NB Power – and other selected stakeholders continue to meet under the sponsorship of the CANDU Owners Group (COG) Radioactive Waste Leadership Forum to discuss opportunities for coordination and collaboration on long-term management matters, including relevant technologies and communication strategies.