A US research team has developed a way to clean the inner walls of a nuclear fusion reactor without opening the vessel to outside air. The technique is designed to address contamination that can remain on reactor components after installation.

The process combines neon plasma with intense heat to decontaminate porous tungsten tiles lining the reactor. According to the reported results, the treatment used temperatures of about 1,472°F and achieved wall purity of 87%.

Because the cleaning takes place inside the reactor, the approach could reduce the need to expose sensitive components during maintenance. Its focus on installed tungsten tiles offers a potential way to improve control of impurities in fusion environments, where wall conditions are important to reactor operation.