The UK Office for Nuclear Regulation (ONR) has formally revoked the nuclear site licence of the Imperial College London Consort Reactor site after nearly 60 years.

“This decision follows many years of work to defuel and then decommission the site in Silwood Park, Ascot, after the shutdown of the Consort research reactor in 2012,” ONR said.

ONR has completed a rigorous assessment of Imperial College London’s application to delicense the site and is satisfied that there is “no danger” and has “ceased to be any danger” from ionising radiations resulting from activities on the site. This has also been independently verified by the UK Health Security Agency.

ONR's CEO and Chief Nuclear Inspector, Mark Foy, said: “The delicensing of the Imperial College London Consort Reactor Site is a significant achievement and the culmination of many years of hard work by all those involved. The requirements for delicensing are very stringent to ensure the continued safety of the public. We must be absolutely certain that a licensee has met the high standards required in order to revoke their site licence.”

He added: “In this case, I am satisfied that all regulatory requirements have been met, and that it is now safe to revoke the site licence. I would like to pass on my thanks and appreciation to the college and its workforce, both past and present, for their professionalism and dedication in ensuring the safe and secure operation of the site over many decades.”

The Imperial College London Reactor Centre was constructed in the early 1960s and the Consort Reactor achieved criticality in 1965. 

The 100kW research reactor was moderated, cooled, reflected and partially shielded by light water. Following a significant decline in the volume of research conducted in the facility, the reactor was shut down in 2012.

Defueling was completed in 2014 and 31 fuel elements removed and transported to Sellafield in Cumbria for interim storage pending reprocessing. Since then, the site has been gradually decommissioned with significant work to clear the site, including demolition of the reactor building itself.

The revocation order means that ONR now regulates 35 licensed nuclear sites in the UK.