Computer program for estimating decommissioning costs of nuclear power plants

Reliable cost estimates are essential for the planning of a decommissioning program for a nuclear facility. The preparation of such cost estimates is a complex task because there are a large number of components, equipment, and piping systems to be considered, many different levels of radioactive contamination and activation levels to be examined, corresponding waste volumes for disposal to be determined and multiple decommissioning scenarios to be evaluated. The DECOM computer program was initially developed in 1983 for use on an IBM main frame computer. In 1985, in order to provide more flexibility and ease of operation for the users of the DECOM computer program, the DECOM Code was converted so as to be usable on an IBM-PC type microcomputer. The DECOM program has been used in the past few years to do decommissioning estimates for both CANDU (Canada Deuterium Uranium) and PWR (Pressurized Water Reactor) type reactors. The estimates have been found to be within the range reported in the OECD (Organization for Economic Cooperation and Development) decommissioning cost surveys. In order to test the validity of the cost estimates prepared using DECOM, a sample of actual cost and manhour data from the Gentilly-1 Decommissioning operation have been processed through the DECOM code and it was observed that the total cost figures were accurate within a 20% range, though costs for individual activities some instances differed. The AECL DECOM computer program, based on the widely accepted unit cost factor approach, is a versatile tool for the applications in decommissioning studies