The UK Government last week announced £220 million ($271m) of funding over the next four years towards the design of a commercially viable fusion power station.
The Spherical Tokamak for Energy Production (STEP) will be based on “spherical” tokamak technology currently being pioneered at the UK Atomic Energy Agency's (UKAEA's) Culham Centre for Fusion Energy (CCFE). The design effort will be led by CCFE and involve over 300 people and be completed in 2024. The objectives of STEP are: to deliver predictable net electricity greater than 100MW; to innovate to exploit fusion energy beyond electricity production; to ensure tritium self-sufficiency; to qualify materials and components under appropriate fusion conditions; and to develop a viable path to affordable lifecycle costs. In August, the UK government announced £20 million for the first year, launching STEP as a collaborative programme involving UKAEA, universities and other organisations.
The CCFE hosts the UK’s and Europe’s foremost fusion research facilities – the Joint European Torus (JET) and the Mega Ampere Spherical Tokamak (MAST). JET, the largest operating fusion project in the world, is funded by the European Union (EU). The most efficient fusion reaction recorded so far at Culham was achieved by JET, when 25MW of energy was inputted and nearly 17MW generated from the subsequent reaction. JET, built in 1983, was designed to study the conditions approaching those in a fusion power plant. It is the only device that can use a deuterium-tritium fuel mix of the kind that is expected to be used for commercial fusion power.
In March, a contract extension for JET was signed by the UK and the European Commission (EC), which will secure at least €100m in additional inward investment from the EU over the next two years, offering some reassurance to more than 500 staff at Culham concerned about their jobs in view of plans for Brexit. The new contract guaranteed its operations until the end of 2020. It also meant JET could conduct a series of key fusion tests planned for 2020, which are seen as a ‘dress rehearsal’ for International Thermonuclear Experimental Reactor (Iter) under construction at Cadarache, France, based on similar technology. ITER is funded by the EU, China, India, Japan, South Korea, Russia and the US, with Europe contributing 45% of the budget and non-EU countries 9% each. The UK participates in Iter through the EU's stake in the project to build the world's first industrial-scale (500MW) demonstration fusion plant. Some €6.07 billion has been proposed by the EC for 2021-2027. The €20 billion Iter project is more than 60% complete and has a completion date of 2025.
However, since 1999, the UK has been pioneering the use of spherical tokamaks through MAST, which contains a spherical plasma, which allows it to confine highly pressurised plasmas with a lower magnetic field that those used in JET.
MAST has just completed a £45m upgrade to MAST-U which will also allow scientists to study plasma conditions relevant to Iter. CCFE secured an additional £21m from the European Fusion Research Consortium and the UK’s Engineering and Physical Sciences Research Council to further enhance the upgrade. This will include doubling the neutral beam injection into the plasma from 5MW with MAST-U to 10MW. This should be complete around 2022. The design for STEP will take account of the results from MAST-U.
The UK’s National Fusion Technology Platform (NFTP), announced earlier this year, is set to open in 2020, with funding of £86 million from UKAEA. NFTP’s main objectives are to identify suitable reactor materials that can stand up to the heat and radiation; and to develop a process to produce one of the fuels for fusion, tritium, as part of the fusion reaction. The results will feed into Iter.
CCFE spokesman Nick Holloway said the centre hoped to stay in Iter after Brexit, and that the new funding for STEP was not related to that decision.
Culham currently has 350 overseas researchers stationed there and continued international co-operation is seen as vital. The continued European funding for JET shows a continued desire to pool resources and knowledge. Colin Walters, the director of NFTP Walters says this is endemic of “the level of interaction”, He believes the agreement for the extension of JET is the only current agreement between the UK and the EU that will be unaffected “whatever form of Brexit or no Brexit”, regardless of “the deal, no deal, good deal, bad deal”.