Public Utilities Reports

PUR Guide 2012 Fully Updated Version

Available NOW!
PUR Guide

This comprehensive self-study certification course is designed to teach the novice or pro everything they need to understand and succeed in every phase of the public utilities business.

Order Now

All Nuclear Power Plants Are Not Created Equal

Fortnightly Magazine - April 1 1998

U.S. plants makes it easier to conduct economic analysis. With the right mathematical techniques, one can isolate precisely the individual economic effects of plant size, vintage and geography. Once this breakdown is done, one may calculate the economic potential for a nuclear plant with any given set of characteristics. This approach is equally valid for costs, labor requirements, safety criteria and plant performance.

The analytical challenge comes in isolating the individual impact of several factors acting together. This task can prove especially difficult where the relationships cannot be approximated by simple, continuous, linear relationships (as with nuclear power plants). That explains why utility analysts using "Multiple Regression" programs have met with limited success in unraveling these relationships. More complex relationships call for a nonlinear, iterative form of "Variance Analysis," as employed here.

Potential Savings: Size, Vintage, Reactor Type

To illustrate how plant characteristics influence performance, we studied the behavior of total non-fuel costs (em O&M plus capital additions (em as a function of capacity factor, overall plant size and vintage, number and type of reactors (dual- or single-unit) and plant location. The analysis was based on individual annual costs of all 71 plants (106 reactors) operating from 1993-1996. Several surprising results emerged.

First, costs appear virtually unrelated to the level of power production (i.e., capacity factor). Except for the impact of price escalation, costs appear constant for any plant depending on its specific characteristics of size, vintage, etc. (Only fuel costs appear directly related to kilowatt-hours produced.)

Figure 4 isolates the impact on total plant costs of the size of the plant in megawatts. Note that for every $52 required to run a 450-MW plant, $130 is needed to run a 1,200 MW plant. However, plants are not members of a single population but fall into one of three size categories: small plants (425-700 MW), medium plants (775-975 MW) and large plants (1,025-1,275 MW). Ninety-five percent of all U.S. plants fall within one of the three tight envelopes shown in the figure.

Rather surprisingly, the operation of U.S. plants shows no economies of scale; the three populations follow closely the line representing a constant dollar/MW relationship. Furthermore, there is an additional 10-percent economic deterioration within each group due to size. When the three cost elements are analyzed separately, it is predominantly the behavior of maintenance and capital additions costs that cause this phenomenon. This cost-size relationship has proven consistent for many years and is therefore unlikely to be easily changed.

Figure 5 shows the impact on total costs due solely to plant vintage, where vintage is defined as the date the plant received its full-power operating license. Under normal circumstances, one might expect to see a slight increase in costs as a plant ages, reflecting higher maintenance needs. As can be seen, however, that is not true here. Instead, "middle-aged" plants appear abnormally expensive. Older plants show a lower cost; plants placed on line most recently now approach the lower cost levels achieved by the older group. What does this curve indicate?

Nuclear plants can be analyzed as falling into one of