[en] The variations in parameters and uncertainties that can affect future waste management program costs are examined. Costs were estimated for both spent fuel and reprocessing waste disposal. Costs for repository site exploration and development, construction and operation of the first two repositories, and waste transportation of either spent fuel or reprocessing waste to the repository were included in the estimate of program costs. Costs for disposing of either spent fuel or reprocessing wastes in four generic geologic media (domed salt, bedded salt, tuff, and granite) were estimated considering uncertainties in package design waste preparation, mining cost, repository layout, repository startup date, and waste shipment distance. The range of these costs is then compared with estimated revenues from the proposed 1-mill/kWh fee to determine whether that fee would provide sufficient funds to meet waste management program needs. The estimated revenues and the range of program cost estimates in 1982 dollar resulting from these variations and uncertainties are shown graphically. The figure shows that the assumed 1-mill/kWh fee provides sufficient revenues to meet program costs for the range of conditions considered. Collection of a 1-mill/kWh fee at the time fuel is irradiated will result in the federal government precollecting for future waste management services. The relationship between funds accumulated to offset future waste management liabilities and the estimated cost of these liabilities will depend on the inflation rate and on the interest the federal government earns on the accumulated funds. If inflation continues, future fee adjustments will be required to assure that adequate funds are available to dispose of wastes when they are received