Initial Safeguards Considerations for the Post Operational Clean Out of a Reprocessing Facility.

Reprocessing facilities on the Sellafield site are close to reaching the end of their operational phase and by the end of 2020 it is anticipated that there will be no nuclear material reprocessing on the Sellafield site. Following cessation of reprocessing operations the facility will transition into a phase of post operational clean out and subsequently a long term phase of surveillance and maintenance or care and maintenance. Post operational clean out relates to the activities undertaken directly after operations cease, to remove residual nuclear material and ultimately enable the effective decommissioning and demolition of the facility. Post operational clean out activities can involve plant modifications to facilitate the re- purposing of installations and the movement of nuclear material and waste products in order to place the facility in a safe and stable condition for future decommissioning operations. In order to comply with international safeguards requirements, the safeguards implementation scheme for a facility transitioning into post operational clean out may require modification to ensure efficient and effective safeguards measures remain in place throughout this phase and to provide assurance of nuclear material control to the safeguards inspectorates. This paper describes the initial safeguards considerations for the post operational clean out of a reprocessing facility on the Sellafield Site. It is beneficial to both Sellafield Limited and the safeguards inspectorates to collaborate in order to facilitate the development of efficient and effective safeguards measures in the post operational environment. The aim is to produce a safeguards implementation scheme that satisfies all stakeholder requirements without placing additional burden upon Sellafield Limited or its regulators. A close rapport has been established between all parties involved and effective stakeholder engagement has resulted in the development of various work streams which will be discussed throughout this paper. This includes the production of a strategy of how the nuclear materials accountancy and safeguards approach for installations will be managed as they transition from operations into the post operational environment.