Kilopower

Kilopower reactor
Prototype NASA 1kW Kilopower nuclear reactor for use in space and planet surfaces
Generation	Experimental
Reactor concept	Stirling engine
Status	In development
Main parameters of the reactor core
Fuel (fissile material)	HEU: 235U
Fuel state	Solid (cast cylinder)
Primary control method	Boron carbide control rod
Neutron reflector	Beryllium oxide radial reflector
Primary coolant	Sodium heat pipes
Reactor usage
Primary use	Long-duration space missions
Power (thermal)	4.3–43.3 kWth
Power (electric)	1–10 kW
Website	www.nasa.gov/directorates/spacetech/kilopower

Kilopower is an experimental U.S. project to make new nuclear reactors for space travel.^[1][2] The project started in October 2015, led by NASA and the DoE’s National Nuclear Security Administration (NNSA).^[3] As of 2017, the Kilopower reactors were intended to come in four sizes, able to produce from one to ten kilowatts of electrical power (1–10 kW_e) continuously for twelve to fifteen years.^[4][5] The fission reactor uses uranium-235 to generate heat that is carried to the Stirling converters with passive sodium heat pipes.^[6] In 2018, positive test results for the Kilopower Reactor Using Stirling Technology (KRUSTY) demonstration reactor were announced.^[2]

Potential applications include nuclear electric propulsion and a steady electricity supply for crewed or robotic space missions that require large amounts of power, especially where sunlight is limited or not available. NASA has also studied the Kilopower reactor as the power supply for crewed Mars missions. During those missions, the reactor would provide power for the machinery necessary to separate and cryogenically store oxygen from the Martian atmosphere for ascent vehicle propellants. Once humans arrive the reactor would power their life-support systems and other requirements. NASA studies have shown that a 40 kW_e reactor would be sufficient to support a crew of between 4 and 6 astronauts.^[1]