The final stage of a clean-up process that has taken several decades was ratified by Parliamentary Under Secretary of State Baroness Verma, who signed orders to revoke the Nuclear Decommissioning Authority’s (NDA) responsibility for the 27 hectares of land. The land will now be released to the partnership that is developing the wider Harwell Oxford campus.

Representing about 20% of the total site, the land, around the size of 40 football pitches, will now be transferred to the wider Harwell Oxford campus that houses a range of high-tech businesses and research organisations.

The parliamentary ‘de-designation’ signifies that the nuclear decommissioning mission is complete, and follows the gradual de-licensing of the land in three separate tranches over the previous six years. Removal of the nuclear licence, which lays down strict conditions about land use and activities, must be approved by the HSE’s Office for Nuclear Regulation.

NDA Property Manager Tony Smithers said: "It is a major achievement to clean up this land so that it can be returned to the commercial market and congratulations must go to Research Sites Restoration Ltd, who operate the site and have driven the decommissioning work forward." Decommissioning work started in 1990s.

RSRL Managing Director Tony Wratten said: "Delicensing and de-designation demonstrates that our work is done on this part of the site. The land can now be re-used without any concern about its previous history."

Harwell was originally a wartime RAF station and become the UK’s first nuclear research centre in 1946. Five experimental reactors were built in the following decades including Europe’s first, known as GLEEP, along with a series of research facilities. Today, the site is a world-leading organisation for science technology and business, which houses more than 150 organisations and employs 4,500 people.