The purpose of this study is to determine the constituents of value in spent nuclear fuel and integrate these results into an economic time dependent model of a spent fuel assembly. The value of the constituents in the spent fuel is balanced against the cost of the various nuclear fuel cycle services. BWR and PWR-UO₂/MOX spent fuel assemblies are modeled at 5 different burnups. The recycle modes that are examined are uranium recycle with and without fission product sales and uranium and plutonium recycle with and without fission product sales. UO₂ and MOX spent fuel assemblies discharged from a nuclear reactor from 1977 to 1990 are modeled for a period of 19 years. Four key results of this study are: (1) a re-examination of the value of recycling materials other than uranium and plutonium, namely cesium-137, 134, rhodium, palladium and xenon is justified; (2) the magnitude of the net profits obtainable from the recycling of spent nuclear fuel are tied primarily to burnup and the decision to sell fission products; (3) for fission product recycle, any burnup yields a net positive value with the greater values being at high burnups; and (4) under only spent uranium and plutonium recycle, it is marginally profitable or unprofitable to recycle spent nuclear fuel. The utilization of cesium-137, 134 in the treatment of municipal sludge can reduce the importation of oil by 47.92 million U.S. barrels annually for the United States. / Master of Science