MOX

With the abandonment of the Fast Breeder reactor programme around the world, BNFL has been forced to seek an alternative use for the plutonium recovered by reprocessing at Sellafield, and which must, under contract be returned to the contract customers. None of these customers have any use for the material in its basic plutonium dioxide powder and weapons-useable form. Instead, some customers have opted to take back their plutonium mixed with uranium as a mixed oxide (MOX) fuel consisting of a mix of around 5% plutonium and 95% uranium. Acknowledged as being more expensive and radiologically more hazardous than conventional uranium fuel, MOX can be used in LWR reactors. For reasons of safety, the reactor load would consist of little more than 30% MOX fuel and 70% conventional fuel. The option of MOX fuel therefore presents BNFL's customers with a less embarrassing option for taking back their plutonium.

MOX flasks bound for Japan approaching Barrow Docks.

A small MOX Demonstration Facility has operated at Sellafield since 1993 and at a production rate of 8 tonnes per year has provided MOX fuel for German, Swiss and Japanese customers. A larger plant with a capacity to produce 120 tonnes per year, the Sellafield MOX Plant (SMP), has been built at Sellafield but currently remains unopened because of significant doubts about its economic viability, and concerns about the safe transport of plutonium fuel around the world and the global risks of plutonium proliferation. Despite BNFL's robust claims for the viability of its new plant, the Government revealed that just 6.7% of SMP's capacity has been contracted.

Deliveries of MOX fuel fabricated in Sellafield's MDF have been made to European customers largely by air from Carlisle Airport. Orders for Japan are transported by sea.

Sellafield currently holds a stockpile of over 66 tonnes of separated plutonium, with more plutonium as yet unrecovered from spent fuel waiting to be reprocessed. This stockpile, which has accumulated as a result of decades of reprocessing is estimated to rise to well over 100 tonnes if reprocessing continues.