Uncertainty clouds long-term future of operating nuclear power plants.

Long-term prospects for the 107 operating plants that supply more than 20% of the Nation's electricity are increasingly unclear, the congressional Office of Technology Assessment (OTA) concluded.

Since 1989, six nuclear power plants have been retired early, well before the expiration of the 40-year operating licenses granted by the NRC. According to OTA, the owners of an increasing number of plants are examining the economics of continued operation versus early retirement as well in the face of an increasingly competitive electric utility industry.

However, judging the industry by early retirements, says OTA, may give a misleading and dim view of the remaining lives of other nuclear power plants because of the great diversity among plants and changing electricity market conditions. OTA finds that no single development is likely to affect uniformly the future of the nation's existing nuclear power plants. Their future is likely to be determined individually over time on a host of separate decisions made by utilities, state utility commissions, and federal regulators. On the plus side, OTA finds that average nuclear power plant operating and maintenance costs have decreased in recent years, reversing a decade long trend of rapid increase. In addition, average plant reliability has improved substantially.

Safety performance has also been good, reports OTA. No core damage accidents have occurred since Three Mile Island in 1979 nor an abnormal number and severity of events that could have led to core damage, much less any actual offsite releases of large amounts of radioactivity, according to OTA. Average occupational radiation exposures, already well below NRC limits, have also declined substantially.

The debate over nuclear power continues. Proponents argue that these plants are vital to reliable, economic electricity supplies; have environmental benefits in emitting no greenhouse gases such as carbon dioxide; and reduce dependence on foreign oil. Opponents argue that nuclear plants bring risks of catastrophic accidents; create unresolved waste disposal; and are often uneconomical. As the plants age, issues related to plant lives and decommissioning are likely to draw more public attention, notes OTA.

No insurmountable industry-wide safety challenges related to nuclear power plants have been identified, says OTA. Current and planned nuclear power plant aging management practices are designed to identify and address challenges before they become a threat and to provide a reasonable assurance of adequate safety. However, some risk will always remain and continued industry and federal regulatory vigilance is crucial. Attention to aging issues is crucial not just in considering license renewal but in a plant's original license term as well, notes OTA.

Because of the industry's youth, experience with nuclear power plants in the second half of their 40-year licensed lives is limited. This factor can be particularly important for some major long-lived equipment such as the reactor pressure vessel, cables, and piping that are intended to function for the full life of a facility.

In several decisions to retire nuclear plants early, aging degradation and its effects on costs and performance played a prominent role, says OTA. Other major factors include rising operational costs, radioactive waste disposal, public attitudes toward nuclear power, and the changing electric industry context, including increased competition and attention to environmental impacts. However, OTA finds the economy of most nuclear power plants appears moderately attractive, assuming the recent leveling of costs continues.

Although work continues to develop and eventually to demonstrate a regulatory process for license renewal, it will be several years before the first application is filed and acted on. Absent license renewal, about three dozen operating nuclear power plants will have to retire in the next 20 years. Federal activities in such areas as nuclear waste disposal and plant safety regulation can have major economic impacts, says OTA. Accelerating these federal efforts could help reduce uncertainty facing utilities and state utility commissions as they make plant life decisions. Federal policies that address climate change and other environmental challenges can also have major impacts on the economics of existing nuclear plants.

Substantial uncertainty remains in decommissioning costs and the adequacy of decommissioning financing in cases of early retirement or rapid cost escalation. If viewed as a one time expense, these costs are not large relative to lifetime plant production costs, says OTA, and suggests that greater use could be made of early retirements as case studies. Perhaps of greater importance is the future disposal capacity and cost for radioactive waste. The NRC has recently undertaken a process to revise residual radioactivity requirements which will determine the level of cleanup necessary for terminating a license. Such standards could have substantial impacts on decommissioning timing and costs. Operating nuclear plants are generally larger and more contaminated than the plants decommissioned to date. However, experience suggests that decommissioning can be performed with existing technologies, according to OTA. Final decommissioning of all but very special cases will likely not be performed before early in the next century.

The OTA report is the product of a request by the Senate Committee on Governmental Affairs and the House Committee on Energy and Commerce and its Subcommittee on Energy and Power. "The OTA's report clearly and extensively describes the various technical, economic, and political factors affecting the aging of nuclear power plants and their eventual decommissioning. Whatever one's view about the future of nuclear power, the report makes clear that federal leadership is critical to provide for the public's health and safety," comments Senator John Glenn, (D-OH), Chairman of the Committee on Governmental Affairs. "The policy issues identified by OTA for possible Congressional action will significantly impact on the economics of nuclear power. I recommend the report as essential reading for anyone involved in this decisionmaking process." Copies of the 183-page report, Aging Nuclear Power Plants: Managing Plant Life and Decommissioning, may be ordered from the Superintendent of Documents, U.S. Government Printing Office at [phone].