Cost Sensitivity Analysis for Consolidated Interim Storage of Spent Fuel: Evaluating the Effect of Economic Environment Parameters

This report evaluates how the economic environment (i.e., discount rate, inflation rate, escalation rate) can impact previously estimated differences in lifecycle costs between an integrated waste management system with an interim storage facility (ISF) and a similar system without an ISF. The costs analyzed in this report are based on the document entitled Cost Implications of an Interim Storage Facility in the Waste Management System, a systems study comparing the “constant dollar” future lifecycle costs of spent nuclear fuel (SNF) management system scenarios. A sensitivity analysis of the economic environment parameters which could impact SNF management system costs for two scenarios—with or without an ISF—was conducted. When setting an initial starting point and ranges for evaluation, historical and recent data, as well as future projections, were all considered. Factors evaluated include general inflation, incremental cost escalation of nuclear projects, and discounting. Breakeven curves were established to illustrate the impact of changing assumptions in discount rate, general interest rate, and incremental escalation rate on the cost difference between the two scenarios. Potential cost savings for the scenario with an ISF were exhibited for low discount rate values, especially with an assumed incremental escalation rate. For higher discount rates, the scenario with an ISF was observed to cost more due to the larger near-term investment required for this option. It should be noted that this analysis did not assign a value to any benefits associated with clearing sites of SNF beyond that associated with discontinuation of direct storage costs, nor did it take into account discounting of any such benefits which, if positive, could favor the ISF-option due to shutdown reactor sites being cleared of SNF sooner than the no-ISF option.