Molten Salt Reactors are liquid-fueled reactors that can be used for production of electricity, actinide burning, production of hydrogen, and production of fissile fuels. Electricity production and waste burndown are envisioned as the primary missions for the molten salt peactors. Fissile, fertile, and fission isotopes are dissolved in a high-temperature molten fluoride salt with a very high boiling point (1,400°C) that is both the reactor fuel and the coolant. The near-atmospheric-pressure molten fuel salt flows through the reactor core. The traditional molten salt reactors designs have a graphite core that results in a thermal to epithermal neutron spectrum. Alternative designs are now being explored with no reactor internals and a fast neutron spectrum. In the core, fission occurs within the flowing fuel salt that is heated to ~700ºC, which then flows into a primary heat exchanger where the heat is transferred to a secondary molten salt coolant. The fuel salt then flows back to the reactor core.