Nuclear fusion could provide the electricity that is needed to power our civilization but there are many technical problems that still need to be solved. Nuclear fusion generates about four times the power of nuclear fission but does not produce the nuclear waste that is piling up at the fission power reactors around the U.S. and around the world.
Nuclear fusion required extremely high temperatures and pressures which damage fusion reactor components. One big problem with using nuclear fusion to generate electricity is the fact that a fusion process which utilizes hydrogen as the plasma in the reactor can generate helium which creates bubbles that weaken the metal of the current fusion reactors designs. At first, tiny bubbles form but as fusion continues, bubbles enlarge and merge to the point where they serious threaten the integrity of the reactor vessel. Now researchers from Texas A&M University are collaborating with researchers from the Los Alamos National Laboratory are working on a possible solution to the problem.
As Michael Demkowicz, of Texas A&M materials and sciences department says, “Literally, you get these helium bubbles inside of the metal that stay there forever because the metal is solid. As you accumulate more and more helium, the bubbles start to link up and destroy the entire material.”
In an article published in the journal Science Advances, the collaborating teams of researchers described how they carried out studies on the behavior of helium gas in nanocomposite materials made out of stacks thick metal layers. They were surprised to find in some of the nanocomposite materials that were tested the helium did not form bubbles as it does in solid metals of current fusion reaction test systems. Long tiny tunnels were formed in the nanocomposite. Demkowicz said, “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.”
Experts are hoping to be able to develop a prototype of a commercial nuclear fusion power reactor by 2030. Much of the current research is dedicated to stabilizing the fusion reaction with various configurations of permanent and electromagnets. While one approach makes use of hydrogen gas isotopes such as deuterium and tritium for the plasma in the reactor, other mixtures of gases are explored to produce non-hydrogen plasmas to generate fusion. Isotopes of helium and lithium are being tested in some reactor designs.
The most immediate use of the new nanocomposite reactors materials is the creation of reactor materials that allow the hydrogen that is generated to flow through the tiny channels in the reactor shell and exit out of the reactor without forming the helium bubbles that weaken current reactors.
Demkowicz believes that the vascular system of channels that form in nanocomposites with the introduction of helium gas may have other important uses. He believes that other things such as heat, electricity and even chemical could flow through the system of channels in the nanocomposite. This could lead to whole new industrial processes.
