work, but the main customer now is the nuclear industry, and the industry pays base costs rather than marginal costs.

• Decommissioning costs are far in the future and can in no way be considered comparable to construction costs. The Atomic Industrial Forum, the only organization that has conducted a detailed study of these costs, concludes that they might, in constant-dollar terms, be as much as 10 percent of original costs.⁶¹ Discounting this estimate at 5 percent over 50 years yields a present worth for this item of less than 1 percent of the original plant cost.

In summary, we consider that the costs of nuclear power, as computed now or projected into the future, represent a fair statement, and that no significant additions to these costs have been identified.*

Nuclear power, as an industry subject to accidents and government regulation, may incur costs from uninsured risks. These arise from the excess costs of replacement power when plants are shut down following an accident or regulatory action. A related set of costs may result from delays in licensing that add to the capital costs of plants under construction.

These risks are subsumed under the capacity-factor projections and the contingencies included in construction schedules that are now part of the industry’s standard accounting. The accident at the Three Mile Island nuclear power plant in 1979 raises the question whether the accounting is adequate. Are the capacity-factor projections and construction schedules that seemed reasonable before this incident still reasonable?

These questions cannot yet be answered. The rate of regulatory shutdown does not appear much greater than the rate prevailing before the accident at Three Mile Island. A licensing hold that has been in effect since then has delayed the schedules of several new reactors, but it may be lifted in the future.

The prolonged shutdown of the Three Mile Island plant represents a financial blow to its operating utility. The loss could be mitigated by an assessment against other nuclear units that would add less than 1 percent to nuclear generating costs. Institutions and arrangements to spread the risks in this or similar ways do not yet exist, but they are being explored. If there were many accidents, the costs would become significant, but in that case, nuclear power would no longer be considered a major energy option.