Toshiba 4S

The Toshiba 4S (Ultra super safe, Small and Simple) is a micro sodium-cooled nuclear fission reactor design.

The plant design is developed by a partnership that includes Toshiba and the Central Research Institute of Electric Power Industry (CRIEPI) of Japan.

These reflector panels replace complicated control rods, yet keep the ability to shut down the nuclear reaction in case of an emergency.

Additionally, the Toshiba 4S utilizes liquid sodium as a coolant, allowing the reactor to operate 200 degrees hotter than if it used water.

[4] A research team including Allison Macfarlane and Rodney C. Ewing evaluated waste production of a number of small nuclear reactors, including the 4s, and published their findings in Proceedings of the National Academy of Sciences of the United States of America.