The fuel leasing option

Three aspects mitigate the business implications of this increase in specific fissile inventory for small reactors of long refuelling interval  

The leasing option may prove to be especially attractive for those small reactor concepts that design for an internal conversion (breeding) ratio of unity . In that case, no loss of fissile mass occurs over the bum-up cycle because of internal breeding. Therefore, as much fissile mass is present in the discharged core as was present initially — necessity for recycle is then driven by the need to refurbish the cladding and load more fertile mass, not by loss of fissile mass. 

Generically, these eould be fast reactors with multiple recycle of all transuranics in the uranium fuel cycle as well as high conversion thermal spectrum reactors with multiple recycle of in the thorium fuel cycle. 

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