Optimization of the back-end services of the fuel cycle is solved by linear programming. A mathematical model governs the flow of fissile material from the reactor to spent fuel storages, to reprocessing and/or ultimate disposal, and to the fabrication of mixed-oxide fuel. The computer program developed is amenable to the optimization of the overall material flow together with recycle schedules and capacities under the prevailing market conditions and their trends. The income tax consideration is not included in the analysis, and therefore the results are applicable mainly to government-owned power production. Using the nuclear program of Finland, calculations are made to study the break-even reprocessing costs with regard to the throwaway costs. According to our conservative price estimates, the recycle benefit amounts to some 6.4 to 6.9% as calculated from the total discounted fuel cost over the years from 1977 to 2004. Over the time period of a few years at the beginning of the plutonium recycle, the levelized costs would be lower in the throwaway case, which is contrary to the overall result.