Fast reactors typically use liquid metal coolants, such as sodium or lead, which have excellent heat transfer properties and do not slow down neutrons. Because they can utilise Uranium-238 (which makes up 99% of natural uranium), they can extend the life of uranium resources by centuries. They can also be configured to consume transuranic elements from spent LWR fuel, potentially reducing the longevity of nuclear waste. Supply chain considerations involve specialized liquid metal handling equipment and high-assay low-enriched uranium (HALEU) or plutonium-based fuels. Technical complexity and high costs currently limit their accessibility.
Overview
Maturity
Safety considerations
The nuclear safety risks associated with fast reactors are related to direct exposure to radiation and contamination through the release of radioactive materials into the environment. This can be due to malfunctions or accidents, or the mismanagement of radioactive waste or spent fuel. Robust safety systems and regulations are essential to minimise these risks.
Security considerations
Stringent security measures are essential to ensure proper control and prevent, detect or respond to theft, sabotage, unauthorized access, illegal transfer or other malicious acts involving the nuclear fuel, other radioactive material or the nuclear facility itself.
Safeguarding considerations
The applicable IAEA safeguards agreement is implemented, involving, for example, inspections, nuclear material accounting, and containment and surveillance measures, to verify the peaceful use of nuclear materials. The implementation of IAEA safeguards is more difficult due to the opaque nature of the liquid metal coolants used in fast reactors, and is more reliant on monitoring sensors and more frequent inspections.
