Scientists at the UK Atomic Energy Authority have successfully tested what is said to be a world-first concept, one that could solve one of the major problems in developing fusion energy.
Initial results from UKAEA’s new ‘MAST Upgrade’ experiment at Culham, near Oxford, in the UK, have demonstrated the effectiveness of an innovative exhaust system designed to help make compact fusion power plants commercially viable.
A key challenge in getting tokamaks like the experimental device at Culham on the electricity grid is removing excess heat produced during fusion reactions.
Without an ‘exhaust’ system that can handle this intense heat, tokamak materials will have to be regularly replaced – significantly affecting the amount of time a power plant could operate for.
The new system, known as a ‘Super-X divertor’, would allow components in future commercial tokamaks to last for much longer, greatly increasing the power plant’s availability, improving its economic viability and reducing the cost of fusion electricity. Tests at MAST Upgrade, which began operating in October 2020, have shown at least a tenfold reduction in the heating undergone by materials with the Super-X system.
UKAEA is planning to build a prototype fusion power plant – known as STEP – by the early 2040s, using a compact machine called the ‘spherical tokamak’. The success of the Super-X divertor is a huge gain for engineers designing the STEP device, as it is particularly suited to the spherical structure.
MAST Upgrade is funded by the UK government’s Department for Business, Energy & Industrial Strategy, the Engineering & Physical Sciences Research Council (EPSRC) and the EUROfusion consortium.
UKAEA’s Lead Scientist at MAST Upgrade, Dr Andrew Kirk, commented:
“These are fantastic results. [This is] 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. Super-X reduces the heat on the exhaust system from a blowtorch level down to more like you’d find in a car engine. This could mean it would only have to be replaced once during the lifetime of a power plant.
“It’s a pivotal development for the UK’s plan to put a fusion power plant on the grid by the early 2040s”.