The objective of the Magnox Operating Plan (MOP) is to enable the UK to meet its international environmental and safety commitments in bringing the Magnox fuel cycle to a close.

The programme determined the closure sequence of the Magnox sites and sets out expected timescales for the completion of defuelling and reprocessing of used nuclear fuel at Sellafield.

The sequence and timings are also used to plan the site transitions from generation to defuelling and into decommissioning.

The MOP has been updated and revised a number of times, and the publication of MOP9 saw a significant change in approach with the inclusion of performance ranges and completion dates, rather than a single rate and set of dates.

In addition, the remaining Dounreay fast reactor breeder material was included in the MOP.