Introduction

Until now, estimating the cost of decommissioning has been a mysterious art form with only a handful of practitioners. DECAS removes the mystery and enables a utility to develop their own estimate that can be defended in rate hearings and modified when conditions dictate. 

Decommissioning Cost Analysis System

The ABZ Decommissioning Cost Analysis System is a user friendly, "rule-based" computer system designed to estimate the costs and cashflows for decommissioning nuclear facilities. Although primarily used for estimating the cost of decommissioning nuclear power plants, DECAS can be used to estimate the cost of any significant engineering project. DECAS is designed to be used with minimal training and without the continued assistance of outside consultants. The program is self-contained, utilizes the most recent cost estimating techniques and can be modified to account for unique site-specific factors.

DECAS is self-documenting. For each element in the estimate, a basis can be specified for subsequent reference. This is especially useful where good data exists from previous plant outages or major modifications. For example, reliable cost data for steam generator removal may be available and incorporated into the decommissioning cost estimate to reduce the uncertainty of nuclear steam supply system removal costs. This approach permits the user to select the best information available, retain this information for easy retrieval and review, and utilize "in-house" expertise in lieu of outside experts. This approach also allows the user to run several different scenarios to test the sensitivity of the cost estimate to anticipated changes (e.g., escalated radioactive waste burial costs, license renewal, et cetera).

DECAS allows information to be entered to different levels of detail. The user inputs data consistent with the level of detail needed for a specific element of the estimate. For example, if the cost of removal of the steam generator is known, no further detail need be included to determine the cost of that removal. On the other hand, if the cost is not known, then the task of removing the steam generator can be broken down into a discrete number of simple elements to estimate the cost. In this way, the level of detail to be input is minimized. This saves time and simplifies the cost estimate. Where unit factors are used, each unit factor can be modified to accommodate site-specific details (unlike other estimating methods which do not permit modification of these unit cost factors). The system contains all required data for generating a nuclear power plant decommissioning cost estimate. No additional spreadsheets or interfacing programs are needed. The user is therefore in complete control of the cost estimate, including such factors as site-specific unit cost factors, staffing size and labor costs.

Conclusions

DECAS reduces the costs of developing decommissioning cost estimates, provides the user with complete control over the estimate and clearly documents the estimate's basis. DECAS is robust, user friendly and completely documented.