In 2005, following the restructuring of the wider nuclear industry, Nexia Solutions was formed out of NSTS, as a wholly owned subsidiary of BNFL.

In October 2006, Secretary of State for Trade and Industry, Alistair Darling, announced the establishment of the NNL, to be based on Nexia Solutions and the British Technology Centre at the Sellafield facility.

[3] On 23 March 2009 it was announced by the Department of Energy and Climate Change (DECC) that a consortium made up of Serco, Battelle and the University of Manchester had been selected as the new management contractors for the NNL.

[8] Mike Lawrence retired in December 2010 and was replaced by Professor Paul Howarth, formerly NNL's Director of Science, Technology and Project Delivery.

[10] In December 2024 the organisation was renamed United Kingdom National Nuclear Laboratory, and began using the royal coat of arms.