TO DELAY OR NOT TO DELAY - FUNDING ADEQUACY ASSESSMENT OF DECOMMISSIONING

摘要

In this paper, we discuss, in economic terms, the two decommissioning choices for a nuclear power reactor - to delay or not to delay. The potential costs and adequacy of decommissioning funds to eventually decommission the nation's nuclear power plants are important issues for the nuclear utilities in the United States. The process of decommissioning is necessary because, following the retirement of a nuclear power plant, a significant radiation hazard remains. We present the results of a cost-based assessment of the two viable decommissioning alternatives for a hypothetical case: in the context of today's changing environment and based on probabilistic modeling. Many factors can affect whether the choice of one or the other alternative will be better in economic terms; i.e., the alternative of lower future cost. In our assessment, we assume that these factors can be viewed as stochastic variables whose future values may vary probabilistically. Accordingly, we constructed a Monte Carlo model to simulate, for a hypothetical reactor decommissioning scenario, the effects of 20,000 random draws for each of our possible assumption factors that will likely affect: (a) the future (present values of) decommissioning costs under each alternative, respectively, and; (b) the measured adequacy of a utility's decommissioning trust fund balance, and the measured adequacy of its recent yearly contributions, as of the present year (to December 2004). Based on the industry status, and combined with the results from our probabilistic modeling, we attempt to answer the question whether a plant owner should choose to immediately decontaminate and dismantle a reactor after shutdown or delay such decommissioning for 20 years. We also identify the factors that are critical in answering this question.