1. Which of the following two alternatives is more expensive?
(a) Unirradiated uranium is used for fabrication of UO2 fuel, enriched to 3.9% in U-235. Assume tails are 0.25%, conversion loss 0.5%, and fabrication loss 0.8%.
(b) Fresh fuel is used for 20% of the core as in (a). The rest of the fuel is made up with recycled plutonium and tails of 0.25%. Assume 0.8 Pu – U-235 equivalence.
Prices: uranium- $45/kg; conversion-$4.50/kgU; SWU cost- $85/SWU; fabrication cost of unirradiated fuel- $210/kgU; reprocessing costs- $750/kgHM; fabrication and transportation of MOX fuel- $400/kgHM; cost of tails- $10/kg; and MOX fabrication loss- 0.8%. For alternative (b), the reprocessing cost is $750/kg of USED SPENT FUEL (so you will need to see how many kilograms of used fuel are required to give you the amount of plutonium needed for the MOX fuel).
NOTE: It may be easiest to specify an arbitrary amount of mass of fuel in the MOX + 20% fresh fuel core such as 1000kgHM. Then, calculate the total cost of the core and divide by the 1000 kg at the end to get the cost per kgHM. Then compare this cost/kgHM for the MOX core with the cost/kgHM of the fresh fuel core from alternative (a).
2. At what reprocessing price would the two alternatives[(a) and (b)] cost the same?