Nuclear fusion breakthrough will prevent reactors blowing up unexpectedly

22 Jun 2017

A small-scale tokamak reactor that would benefit from this new method. Image: Mishakov Valery/Shutterstock

The latest breakthrough in nuclear fusion energy is quite important as it prevents any runaway electrons from severely damaging a reactor without warning.

A future where clean, safe and near limitless energy is provided by nuclear fusion technology is becoming less like science fiction and more like an inevitability, at least based on recent updates from the scientific community.

However, before we can get to that point, we still have to iron out quite a few kinks in the design of reactors to make sure that they are not only efficient, but completely safe.

Future Human

That is why the latest breakthrough made by a pair of researchers from Chalmers University of Technology in Sweden is so significant because, with their model, future reactors are a lot less likely to completely destroy themselves.

In one of the more popular reactor types, known as a tokamak, to create fusion energy takes high pressure and temperatures of about 150m degrees Celsius in order to get atoms to combine.

But, during this process, one of the potential hazards is the generation of runaway electrons, which, without warning, can destroy the reactor wall if they are bouncing around fast enough due to their extremely high amounts of energy.

To try to prevent this, researchers Linnea Hesslow (24) and Ola Embréus (25) revealed that it is possible to decelerate runaway electrons by injecting so-called heavy ions in the form of gas or pellets.

By pumping elements such as neon or argon into the reactor, the electrons collide with the nuclei of the ions, resulting in a drop in speed due to increased resistance, and they would therefore be controllable by a reactor supervisor.

These findings were published in a paper in Physical Review Letters.

‘We are trying to harvest stars here on Earth’

Using mathematical descriptions and plasma simulations, the researchers said it is possible to predict the electrons’ energy and how it changes under different conditions.

“When we can effectively decelerate runaway electrons, we are one step closer to a functional fusion reactor. Considering there are so few options for solving the world’s growing energy needs in a sustainable way, fusion energy is incredibly exciting since it takes its fuel from ordinary seawater,” explained Hesslow.

While nuclear fusion remains a long-term goal, with only a few brief glimpses of stable forms of the energy achieved so far, Hesslow added that her and Embréus’s research is important to help solve future energy demands.

“You could say that we are trying to harvest stars here on Earth, and that can take time,” she said.

“It takes incredibly high temperatures, hotter than the centre of the sun, for us to successfully achieve fusion here on Earth. That’s why I hope research is given the resources needed to solve the energy issue in time.”

Colm Gorey was a senior journalist with Silicon Republic