Transatomic Power is based on inventions developed by Dr. Dewan and Mark Massie while graduate students in the MIT Department of Nuclear Science and Engineering. The reactor uses nuclear fuel dissolved into a molten salt, rather than the solid fuel of conventional nuclear reactors. This liquid fuel makes it possible to generate power at atmospheric pressure, greatly reduce the creation of long-lived nuclear waste, and improve safety and cost. The basic approach was demonstrated in the 1960s, and now the pair has developed key material and design improvements that could increase the reactors effectiveness up to 100-fold and transform the nuclear industry.
Molten salt reactor designs are appealing because they are essentially immune to meltdowns like the one we saw at Fukushima. A standard nuclear plant is cooled by water, which boils well below the 2,000 degrees Celsius at the core of a nuclear fuel pellet. The fission happening in these reactors is a chain reaction, meaning it keeps going until we stop it, or it runs out of fuel. Shutting down one of these reactors means pumping in water until it has cooled, which can take a long time. If that doesn’t happen — because maybe you had to run away from radiation — the reaction continues out of control and you can get a meltdown.
Future TAP Designs
The basic TAP reactor design described in this report will benefit from future innovations in a number of different ways. Improvements to complementary technology will become commercially available over time. These technologies include high temperature ceramics such as SiC-SiC composites for heat exchangers and other reactor internals, which will allow us to increase the reactor’s operating temperature and increase thermal efficiency. The helium sparging in the primary loop off-gas system may be replaced by more advanced cryogenic removal methods. Furthermore, we will likely be able to incorporate closed loop Brayton cycles or open loop air turbine cycles in the future.