Aerospace and Defense

Testing on a kilowatt-scale nuclear reactor that could serve as the power source for crewed missions on Mars, the Moon or other extraterrestrial destinations was initiated by NASA and the U.S. Department of Energy in November 2017. Kilopower is a small, lightweight fission power system capable of providing up to 10 kW of electrical power, sufficient to supply several average households continuously without refueling for at least 10 years. For NASA missions, four Kilopower units would provide enough power to establish an outpost and provide onboard lighting, water and oxygen.

Now the agency, in collaboration with the U.S. Department of Energy’s National Nuclear Security Administration (NNSA), reveal the results of the Kilopower Reactor Using Stirling Technology (KRUSTY) experiment conducted at the NNSA’s Nevada National Security Site. The evaluations were designed to demonstrate full functionality of the reactor works and that it is safe under abnormal circumstances. Two tests were conducted without the reactor generating power to test the components and a third increased power in stages. The final trial was a 28-hour, full-power mission simulation that included reactor startup, ramp to full power, steady operation and shutdown.

Kilopower was confirmed to operate and handle multiple failures during simulated power reduction, failed engines and failed heat pipe events.

The prototype power system uses a solid, cast uranium-235 reactor core, about the size of a paper towel roll. Passive sodium heat pipes transfer reactor heat to high-efficiency Stirling engines, which convert the heat to electricity.