Most emerging nuclear energy systems are in the early phases of the research, development, design, and deployment life cycle and/or represent pioneer or first-of-a-kind projects; hence, the uncertainties associated with capital and life cycle costs are often considerable. The type of cost estimate prepared for a given system also depends heavily on the system's development/deployment status, and the cost projections prepared prior to the decision to construct a facility or system often do not incorporate all of the relevant uncertainties.

The purpose of this paper is to survey the types of cost estimates typically prepared for selected nuclear systems at various stages of project development and to describe cost-engineering methodologies which may be used to produce more meaningful and realistic estimates. Examples utilizing nuclear technologies evaluated at Oak Ridge are used to illustrate these methods. Among the techniques considered are probabilistic cost-risk analysis, parametric cost models coupled to system/process performance and design models, and cost growth models based on historical experience with pioneer technologies. In addition to the above survey, the author discusses pitfalls and problems associated with early cost projections. A major premise is the fact that the standard “estimator's contingency” usually does not cover the myriad economic risks inherent to emerging energy-related or nuclear systems.