Molten Salt Reactors

MSRs utilise molten salts, such as fluoride or chloride salts which acts as the heat transfer medium. The fuel (uranium or thorium) is dissolved in the salt, circulating through the reactor core where it undergoes the nuclear fission reaction. The heat generated is transferred to a heat exchanger, which produces steam to drive a turbine and generate electricity. The liquid fuel nature of MSRs provides several advantages, including inherent safety features, higher thermal efficiency, and the ability to process and recycle spent fuel online. Supply chain considerations involve the availability of specialised materials for the reactor vessel, fuel salts, and heat exchangers. Logistical challenges include the transportation and installation of large and complex equipment. Accessibility for developing countries is influenced by the high cost and technical expertise required for operation and maintenance.

While the fundamental technology is proven, MSRs are still in the testing and demonstration phase, with ongoing efforts to improve their performance and reliability.

Similar to other nuclear reactors, the nuclear safety risks associated with MSRs 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.  MSRs have inherent safety features, such as passive decay heat removal and the ability to drain the fuel salt in case of an emergency. Nevertheless, robust safety systems and regulations are essential to minimise the nuclear safety risks. Further, the use of molten salts requires careful materials selection and corrosion management within the reactor.

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.

The applicable IAEA safeguards agreement will be implemented, involving, for example, inspections, nuclear material accounting, and containment and surveillance measures, to verify the peaceful use of nuclear materials. The liquid fuel nature of MSRs presents unique challenges for safeguards implementation, considering also that MSRs can use a variety of fuel cycles, based on uranium, plutonium or thorium.