United Kingdom

31 December 2022

The UK has nine operable reactors at seven sites; eight are advanced gas-cooled reactors (AGRs), with one pressurized water reactor (PWR) at Sizewell. The AGRs are due to be retired by the end of the decade. Two EPR units are under construction at Hinkley Point.

In April 2022 the Office for Nuclear Regulation began the generic design assessment (GDA) process for the 470 MWe Rolls-Royce SMR design. In November 2022 Rolls-Royce announced that it had identified four potential sites – Sellafield, Trawsfynydd, Wylfa and Oldbury – to deploy Rolls-Royce SMR plants, along with three possible sites to host its first factory for producing SMR components – Sunderland, Redcar and Deeside.

In November 2022 the government announced that the UK would invest $679 million ($815 million) and become a 50% partner with EDF in Nuclear New Build Generation (SZC) Ltd (NNB SZC), which aims to install and operate two EPR units at Sizewell C. It said the investment allowed for China General Nuclear’s exit from the project. NNB SZC signed an early framework agreement in December 2022 with Framatome covering initial engineering and procurement activities.

In March 2023, the government announced the launch of ‘Great British Nuclear’, aimed at providing up to a quarter of UK electricity generation by 2050 from nuclear, as well as a competition for SMR funding.

Figure Un1. Annual electricity output (TWh) and age of reactors (years) at time of generation


Figure Un2. Average capacity factor of reactors in United Kingdom


Figure Un3. Emissions avoidance through use of nuclear generation in United Kingdom


UK 'to class nuclear as environmentally sustainable' : World Nuclear News - 15 March 2023

First reactor vessel for Hinkley Point C completed : World Nuclear News - 16 December 2022

Three UK sites in running to host first Rolls-Royce SMR factory : World Nuclear News - 19 December 2022