Team works on concept for nuclear-powered space flight

The research team recently demonstrated the first use of a heat pipe to cool a small nuclear reactor and power a Stirling engine at the Nevada National Security Site’s Device Assembly Facility near Las Vegas.

The Demonstration Using Flattop Fissions (DUFF) experiment is said to have produced 24W of electricity. A team of engineers from Los Alamos National Laboratory (LANL), NASA’s Glenn Research Center and National Security Technologies LLC (NSTec) conducted the experiment.

A heat pipe is a sealed tube with an internal fluid that can transfer heat produced by a reactor with no moving parts, while a Stirling engine converts heat energy into electrical power using a pressurised gas to move a piston. According to LANL, using the two devices in tandem allowed for creation of an electric power supply that can be adapted for space applications.

Researchers configured DUFF on an existing experiment, known as Flattop, to allow for a water-based heat pipe to extract heat from uranium. Heat from the fission reaction was transferred to a pair of free-piston Stirling engines manufactured by Sunpower Inc, based in Athens, Ohio. Engineers from NASA Glenn designed and built the heat pipe and Stirling assembly, and operated the engines during the experiment. Los Alamos nuclear engineers operated the Flattop assembly under authorisation from the National Nuclear Security Administration (NNSA).