What is Nuclear Fusion?

The US Department of Energy announced on Tuesday a “major scientific breakthrough” in the field of nuclear fusion.

For decades, scientists have been trying to generate energy with this mechanism, which has many advantages: it does not generate CO2, produces less radioactive waste than previously known nuclear energy and does not pose the risk of accidents.

Fusion differs from nuclear fission, the technique currently used in nuclear power plants which involves breaking the bonds of atomic nuclei to release energy.

Fusion is the reverse process: it involves the fusion of two light nuclei (hydrogen for example), to create a heavy one (helium), and this too releases energy.

It is the process that occurs in stars such as the Sun.

“Controlling the energy source of stars is humanity’s greatest technological challenge,” physicist Arthur Turrell, author of the book “The Star Builders,” wrote on Twitter.

Melting is only possible by heating materials to extremely high temperatures, above 100 million degrees Celsius.

“Mechanisms have to be found to insulate this extremely hot matter from anything that could cool it,” Erik Lefebvre, project manager at France’s Atomic Energy Commission (CEA), told AFP.

For decades, scientists have tried to ensure that the energy produced by nuclear fusion exceeds that used to cause the reaction.

According to the Financial Times, this will be announced on Tuesday by the US National Ignition Facility (NIF).

It is about demonstrating that a ‘net energy gain’ is possible, a crucial step that many scientists around the world are excited about.

But “the road is still very long” before “an industrial-scale and commercially viable demonstration”, warns Erik Lefebvre, for whom these projects still require 20 or 30 years of work.

Unlike fission, fusion does not carry the risk of a nuclear accident. If there’s a system failure, the reaction simply stops, Lefebvre explains.

Furthermore, smelting produces less radioactive waste than is generated by current power plants. And it does not produce greenhouse gases.

“It is a completely decarbonised energy source, which generates little waste, and which is inherently very safe” for what would be “a future solution to energy problems on a global scale”, summarizes Lefebvre.

Due to its state of development, it does not represent an immediate solution to the climate crisis and the need for a rapid transition away from fossil fuels.

Source: AFP