(a) The methodology used to calculate plutonium discharges for Table A1 makes several simplifying assumptions. Corrections account for two factors that lead to overestimates in the plutonium inventory. The first reduces the total inventory by the amount of plutonium 241 that has decayed. The second correction accounts for the reduction in plutonium, based on an estimate of the total amount of separated plutonium irradiated as MOX fuel in LWRs. The calculation of the amount of plutonium in discharged fuel (Table A1) assumes that all the LWR fuel is enriched uranium; this calculation does not account for the amount of separated plutonium initially inserted into a reactor in the form of MOX fuel and subsequently fissioned in the reactor. Breeder reactors are ignored here.