Small Modular Molten Thorium Salt Based Fission Reactors

Small Modular Molten Thorium Salt Based Fission Reactors (MSRs) utilizing thorium fuel cycles combine advanced fission technology with enhanced safety, sustainability, and proliferation resistance. These reactors dissolve fissile and fertile materials directly in fluoride salt coolants (typically LiF-BeF2-ThF4 mixtures) that remain liquid at atmospheric pressure across operating temperatures of 600-750°C. The thorium-232 breeding cycle captures neutrons to produce uranium-233, a superior fissile isotope with excellent neutron economy and reduced higher actinide production. Modular designs ranging from 50-300 MW electrical output enable distributed deployment, matching energy demand to local grids and minimizing transmission losses. The liquid fuel form provides revolutionary advantages: continuous fuel processing removes fission products and maintains optimal neutron balance, negative temperature and void coefficients ensure inherent stability, and freeze plugs in drain tanks provide fail-safe core drainage during off-normal conditions. MSRs operate at atmospheric pressure, eliminating high-pressure accident scenarios and reducing containment requirements. The high-temperature operation enables efficient electricity generation (40-45% thermal efficiency versus 33% for light water reactors) and supports process heat applications including hydrogen production, desalination, and industrial process integration. Thorium fuel offers 3-4 times greater natural abundance than uranium, with deposits distributed globally reducing geopolitical supply concerns.