Thirty years later it was recognised that its useful life was over and the decision was taken to close the reactor. The project aim was to remove the reactor and delicense the site in such a way that the other research work could proceed with minimum disruption, leaving the research institute intact. Early discussions with the Nuclear Installations Inspectorate (NII) on the interpretation of the extremely stringent regulatory requirements indicated the difficulty (if not impossibility) of the task. However, with the full cooperation of the NII, a two-step approach was devised which resulted in the University having, for a few months, the smallest licensed site in the world before the licence was finally revoked.

Professor Roger Scott(1941- )was a key figure in securing the funding to initiate reactor decommissioning. He played a major role in the team which successfully decommissioned the reactor and he was the architect of the successful effort to delicense the nuclear site. By clear strategic thinking, a detailed technical and legal knowledge of the practical, policy, and regulatory issues involved, and by quiet but determined diplomacy he achieved a goal whose cost-benefit ratio to science in the country was astonishingly low - perhaps by an order of magnitude compared to today's estimates for comparable reactors.

One of the principal areas of the work undertaken was the effort expended on the determination of the radioisotope abundance of the reactor structure and thereby its impact on the characterization of waste for disposal and the radiation dose budget for personnel. Extensive use was made of remotely operated vehicles to minimize this dose.