Sodium-cooled fast reactor

For example, in 2022, in the US, TerraPower (using its Traveling Wave technology[2]) is planning to build its own reactors along with molten salt energy storage[2] in partnership with GEHitachi's PRISM integral fast reactor design, under the Natrium[3] appellation in Kemmerer, Wyoming.

[4][5] Aside from the Russian experience, Japan, India, China, France and the USA are investing in the technology.

The second is a medium to large (500–1,500 MWe) sodium-cooled reactor with mixed uranium-plutonium oxide fuel, supported by a fuel cycle based upon advanced aqueous processing at a central location serving multiple reactors.

The US EBR-2, French Phénix and others used this approach, and it is used by India's Prototype Fast Breeder Reactor and China's CFR-600.

By comparison, the liquid temperature range of water (between ice and gas) is just 100K at normal, sea-level atmospheric pressure conditions.

[7] The fact that the sodium is not pressurized implies that a much thinner reactor vessel can be used (e.g. 2 cm thick).

For example, air ducts can be engineered so that all the decay heat after shutdown is removed by natural convection, and no pumping action is required.

A disadvantage of sodium is its chemical reactivity, which requires special precautions to prevent and suppress fires.

In addition, neutron capture causes it to become radioactive; albeit with a half-life of only 15 hours.

Magnesium oxide has an order of magnitude lower probability of interacting with neutrons (thermal and fast) than elements such as iron.

Innovations can reduce capital cost, such as modular designs, removing a primary loop, integrating the pump and intermediate heat exchanger, and better materials.

On November 30, 2019, CTV reported that the Canadian provinces of New Brunswick, Ontario and Saskatchewan planned an announcement about a joint plan to cooperate on small sodium fast modular nuclear reactors from New Brunswick-based ARC Nuclear Canada.