Can we control what we can’t count? The challenges involved in safeguarding closed fuel cycles which include electro-processing.

Materials of proliferation sensitivity (principally in this context high enriched uranium and separated plutonium) are at their most vulnerable to theft or sabotage during transport. On physical protection grounds, therefore, it makes sense to minimise the transport of materials of proliferation sensitivity. One way this can be achieved in the context of a closed nuclear fuel cycle is by the collocation of all of the facilities involved in the generation, processing, fabrication and use of these materials on a single site. For example if fuel fabrication, power generation and reprocessing facilities could be combined on the one site there would be no need for inter-site transportation of the related proliferation sensitive materials. Electro-processing as part of such an integrated system would provide a series of non-proliferation benefits, principally arising from the absence of fully separated plutonium from the closed cycle. But electro-processing also presents a series of real challenges to the safeguards system; principally these challenges arise from the difficulties in making quantitative safeguards measurements of fissile materials at different stages of an electro-based fuel cycle. While boundary control measures can be used to ensure that material is not diverted without detection, no such system can be perfect and loss of continuity of knowledge of materials inventories is always a possibility. How can the IAEA re-establish knowledge of inventories when those inventories cannot be accurately verified to within current limits? This paper will examine the challenges involved in safeguarding closed fuel cycles which include electro-processing.