The UK government is looking for a location to build its "Spherical Tokamak for Energy Production" (STEP). The hope is to start constructing the prototype fusion reactor by 2032 and have it generating power by 2040.
From the UK Atomic Energy Authority website:
Fusion is the process that takes place in the heart of stars and provides the power that drives the universe. When light nuclei fuse to form a heavier nucleus, they release bursts of energy. This is the opposite of nuclear fission – the reaction that is used in nuclear power stations today – in which energy is released when a nucleus splits apart to form smaller nuclei.
To produce energy from fusion here on Earth, a combination of hydrogen gases – deuterium and tritium – are heated to very high temperatures (over 100 million degrees Celsius). The gas becomes a plasma and the nuclei combine to form a helium nucleus and a neutron, with a tiny fraction of the mass converted into 'fusion' energy. A plasma with millions of these reactions every second can provide a huge amount of energy from very small amounts of fuel.
One way to control the intensely hot plasma is to use powerful magnets. The most advanced device for this is the 'tokamak', a Russian word for a ring-shaped magnetic chamber. CCFE's goal is to develop fusion reactors using the tokamak concept.