2012 Springer Science+Business Media, LLC. All rights reserved. Fuel management deals with the irradiation and processing of fuel. An analysis of the fuel cycle is necessary to estimate fuel costs and to define operational requirements such as initial fuel compositions, how often to refuel, changes in power densities during operation, and reactivity control. The great flexibility of fast spectrum systems allows them to either breed desired fuel or burn undesired wastes-particularly the minor actinides (MA),1 which constitute the greatest long-term contribution to radiotoxicity and heat load in geologic waste repositories. Fuel costs represent one contribution to the total power costs, as discussed in Chapter 3. Unlike the light water reactor (LWR), fuel costs for a fast soectrum reactor are insensitive to U3O8, price. Hence, this contribution to total power cost is predicted to be lower for a fast breeder reactor than for a thermal reactor as the price of U3O8, rises. Since more fissile material is produced in a breeder reactor configuration than is consumed, the basic (feed) fuel for the fast breeder reactor is depleted uranium, which is available for centuries without further mining of uranium ore.