Clean energy from fusion is a step closer with the launch of the MAST Upgrade tokamak.
After a seven-year build, the UK Atomic Energy Authority (UKAEA)’s £55M-machine, labelled Mega Amp Spherical Tokamak (MAST) Upgrade, has achieved “first plasma” – where all the essential components work together simultaneously.
The project at Culham Centre for Fusion Energy was funded by the Engineering & Physical Sciences Research Council, part of UK Research & Innovation and the Department for Business, Energy & Industrial Strategy.
Fusion energy offers the potential of an abundant, inherently safe low-carbon electricity supply (the raw materials are found in seawater and the Earth’s crust). It involves fusing hydrogen particles in a hot gas known as a ‘plasma’ to unlock large amounts of energy.
Operating fusion technologies requires a careful balancing act of controlling extreme heat, gas and powerful magnetic fields, amongst other complex systems.
Super-X factor
One of the biggest challenges in fusion research has been to extract the amount of excess heat from the plasma. UKAEA’s scientists now plan to test a new exhaust system called the ‘Super-X divertor’ at MAST Upgrade.
This system is designed to channel plasma out of the machine at temperatures low enough for its materials to withstand – meaning that components can last much longer. The approximate tenfold reduction in heat arriving at the internal surfaces of the machine has the potential to be a game-changer for the long-term viability of future fusion power stations.
A step towards fusion power
MAST Upgrade will be the forerunner of the UK’s prototype fusion power plant, Spherical Tokamak for Energy Production (“STEP”), due for completion by 2040.
STEP – which UKAEA is designing in an initial £220 million programme funded by the UK Government – will be based on MAST Upgrade’s ‘spherical tokamak’ fusion concept. The spherical tokamak could offer a route to a compact fusion power plant.
The success of MAST Upgrade is another step along the way to designing future fusion power facilities, which could have an important role as part of a future portfolio of low-carbon energy. MAST Upgrade will also aid preparations for ITER – the world’s largest science megaproject, now being built in the South of France, which intends to demonstrate fusion power on an industrial scale.
