Commercially viable fusion electricity comes a step closer with promising UK results

Researchers at the Culham Centre for Fusion Energy believe they have solved the exhaust problem for fusion power plants

Researchers at the Culham Centre for Fusion Energy (CCFE) in Oxfordshire on Wednesday released the first results from the MAST-U (Mega Amp Spherical Tokamak - Upgrade) nuclear fusion experiment, suggesting that the dream of creating commercially viable fusion power plants could be a step closer to reality.

The scientists claim that they have developed an exhaust system that can help deal with the immense temperatures created during the fusion process and can reduce the exhaust heat load by ten-fold.

The MAST-U device at the CCFE is a £55 million machine that began operating in October last year.

The device is based on the original MAST machine, which was built in 1999 and ran until 2013. After that, it underwent an upgrade to have new diagnostic tools, new power supplies, longer pulses, stronger magnetic field, increased heating power and an innovative new plasma exhaust system.

The MAST upgrade work was completed in late 2019 and last year, scientists achieved the first plasma of deuterium within the machine.

According to the MAST-U team, this machine particularly focuses on plasma exhaust - an issue that must be solved to achieve commercial fusion power.

Without an effective exhaust system, the excess heat can damage materials inside a reactor, limiting the amount of time a reactor could operate for.

MAST-U is the first tokamak (magnetic plasma confinement device) to test the 'Super-X divertor' - an exhaust system designed to deal with excess heat produced by fusion reactions.

According to the researchers, the results of the initial experiments show that the new Super-X divertor system incorporated in MAST-U can reduce the exhaust heat load ten-fold.

The team believes that the new system can allow components in future tokamaks to last for much longer, immensely increasing availability of the power plant while also reducing the cost of fusion electricity.

"These are fantastic results," said Dr Andrew Kirk, UKAEA's lead scientist at MAST-U.

"They are the moment our team at UKAEA has been working towards for almost a decade. We built MAST Upgrade to solve the exhaust problem for compact fusion power plants, and the signs are that we've succeeded."

"It's a pivotal development for the UK's plan to put a fusion power plant on the grid by the early 2040s - and for bringing low-carbon energy from fusion to the world," he added.