Executive Summary

This research report provides an overview of the radioactive waste forms expected to be generated throughout the lifecycles of small modular reactor (SMR) design types that are planned or being evaluated for deployment in Canada. It also analyzes the current Canadian regulatory and standards-based requirements for radioactive waste management with respect to waste from SMRs and provides recommendations based on this analysis. The report summarizes the radioactive waste forms expected to be generated throughout the lifecycles of 12 different SMRs from the following design types:

• Light water reactor (LWR)
• High-temperature gas-cooled reactor (HTGR)
• Molten salt reactor (MSR)
• Lead-cooled fast reactor (LFR)
• Sodium-cooled fast reactor (SFR)
• Heat pipes/solid core reactor

In addition, the report presents a review of the CSA N292 Series of standards, and identifies gaps and recommendations related to their applicability to radioactive waste from SMRs.

For the purposes of this report, pressurized heavy water reactors (PHWRs) were considered as the baseline for existing standards and regulations in Canada. The findings indicate that LWR designs produce radioactive waste forms similar to those of PHWRs. HTGR designs produce a few novel waste forms and materials, while MSR, LFR, and SFR designs produce multiple novel waste forms, unique radionuclides, requirements for processing, and other radioactive waste considerations. In all cases, the used nuclear fuel is physically different in size, shape, and mass to current fuel bundles used in Canadian reactors.

The findings also indicate that current Canadian standards are generally broad and include radioactive waste from various sources, including SMRs. Some recommendations are provided for future revisions of the standards to ensure that they fully address waste from SMRs. The key waste features that could be addressed by current standards include:

• Enrichment of fuel, which requires non-proliferation measures, criticality measures, and additional security for highly enriched fuel;
• Graphitic waste, which may require additional consideration due to flammability and explosion hazards, and may require new packaging;
• Additional toxicity and environmental concerns with liquid lead or liquid sodium-cooled reactors.