Such a reactor could provide energy to ships and other autonomous objects.
The US Nuclear Regulatory Commission has issued a permit for the construction of a nuclear power plant with a reactor on molten salts – a rector, in which the basis of the coolant is a mixture of molten salts, which can operate at high temperatures while remaining at low pressure.
Almost all nuclear reactors in operation today use water for cooling. However, their cores can reach temperatures of 300°C, which is much higher than the boiling point of water at 100°C – to prevent evaporation and keep water in a liquid state at such high temperatures, great pressure is needed, which, in turn, requires additional technologies, space . and money On the other hand, some salt mixtures have higher boiling points, so they do not require such expensive high-pressure environments.
“You can run it at such high temperatures and it won’t boil over,” Nicholas W. Smith, head of the molten chloride reactor experimental project at the Idaho National Laboratory, told Business Insider. “You don’t have to have big fat pressure tanks to hold the coolant.”
The first molten salt reactor, tested back in the 1950s, was small enough to fit in an airplane, while, for example, the part of the Diablo Canyon Nuclear Power Plant in California that produces energy occupies 50,000 square meters. of land, according to Berkeley Engineering.
Molten salt reactors have not been used by the US since the 1970s.
The project is led by Kairos Power, a company that plans to build a test station called Hermes with a reactor that will be cooled by molten fluorine salts in Oak Ridge, Tennessee, as early as 2027. The first version will not supply electricity, but the company hopes that its successor, Hermes 2, will do so by 2028.
Hermes is set to operate at temperatures up to 650℃, and its coolant mixture made of lithium fluoride and beryllium fluoride boils at about 1500℃, well above the temperature of the reactor core. Thus, the coolant will be liquid without additional pressure.
Kairos Power also plans to use TRISO pellet fuel, which the US Nuclear Energy Administration says can withstand extreme temperatures better than current fuel, reducing the chance of releasing radioactive fission products.
At the same time, challenges remain, and the main one is finding an effective way to limit corrosion.
“Oxygen is kind of the driving force behind molten salt corrosion,” Smith said.
Another drawback is that such reactors will produce multiple waste streams and may face disposal issues.
In Japan, the world’s largest tokamak – a 370-ton thermonuclear reactor – was launched
