Helium-resistant material could enable stable nuclear fusion

Engineers and researchers from Texas A&M University and the Los Alamos National Laboratory in New Mexico have found a way to prevent helium, a by-product of the fusion reaction, from weakening nuclear fusion reactors.

According to the team, the secret is to build reactors using nanocomposite solids that create channels through which the helium can escape.

Nuclear fusion is capable of generating about four times the power of nuclear fission, but as promising as fusion is, researchers have yet to figure out how to turn it into a reliable source of truly renewable energy.

Not only does the fusion process expose reactors to extreme pressure and temperatures, helium adds to the strain placed on reactors by bubbling out into the materials and eventually weakening them.

Michael Demkowicz, Texas A&M materials science and engineering associate professor, said: “As you accumulate more and more helium, the bubbles start to link up and destroy the entire material.”

The researchers tested the behaviour of helium in nanocomposite solids, materials made from thick metal layer stacks. They found that the helium didn't form bubbles in these like it did in traditionally used materials. Instead, it formed long, vein-like tunnels.

“We were blown away by what we saw,” said Prof Demkowicz. “As you put more and more helium inside these nanocomposites, rather than destroying the material, the veins actually start to interconnect, resulting in kind of a vascular system.”

The vein-like tunnels can serve as channels for helium to pass through, but Prof Demkowicz believes that's just the start.

“What else could be transported through such networks?” he asked. “Perhaps heat or electricity or even chemicals that could help the material self-heal.”