Molten salt nuclear reactors are safe, clean

Molten salt reactors are becoming a reality. Not only can they generate electricity safely, they produce large amounts of excess heat which heavy industry can use. Plus, solar and wind plants can store power as heat in the molten salt for later use and these reactors are especially good for providing cheap power for desalination.

Researchers at NRG, a Dutch nuclear materials firm, have begun the first tests of nuclear fission using thorium salts since experiments ended at Oak Ridge National Laboratory in the early 1970s.

Thorium has several advantages over uranium, the fuel that powers most nuclear reactors in service today. First, it’s much harder to weaponize. Second, as we pointed out last year in a long read on thorium-salt reactors, designs that call for using it in a liquid form are, essentially, self-regulating and fail-safe.

Molten salt reactors have many uses.

Desalination of seawater and brackish water is extremely energy intensive. The IMSR is uniquely suited to provide clean, heat energy and electric power on an industrial scale needed at cost-competitive prices to enable far greater deployment of desalination technologies today.

In addition to utilizing heat energy for desalination, hot industrial salts can be directed to a hot salt mass energy storage, a method that is already in use today. These hot salt thermal energy reservoirs supported by IMSR heat can be used as a grid sink for excess Wind and Solar electric power production. This system negates any need for grid-based electric power storage and is highly complementary to wind and solar power production. The cheap and effective salt-based thermal storage would act as an energy battery that will allow the demand curve to be supplied at the appropriate service levels without damaging surges taxing the grid system.

A US company is building them.

Terrestrial Energy’s Integral Molten Salt Reactor is designed to meet the rapidly rising demand for breakthrough energy technologies that can deliver clean, scalable, and cost-competitive heat and power to displace fossil-fuel combustion starting in the 2020s. The IMSR® is a fundamentally different reactor. It employs advanced molten-salt technology, which creates a far superior system to harness clean bountiful energy of the atom simply, safely and economically.


Also the fuel in an MSR is already in liquid form, it cannot melt down and in an emergency situation it can be quickly drained out of the reactor into a passively cooled dump tank. MSRs designs have a freeze plug at the bottom of the core—a plug of salt, cooled by a fan to keep it at a temperature below the freezing point of the salt. If temperature rises beyond a critical point, the plug melts, and the liquid fuel in the core is immediately evacuated, pouring into a sub-critical geometry in a catch basin. This formidable safety tactic is only possible if the fuel is a liquid.