The US Supreme Court has dramatically drawn the nation's attention to the economics of nuclear power and what the public can do about it. The unanimous ruling on a California case this week gives states a green light to block new nuclear plants on economic grounds.
Already several states have statutes similar to the 1976 California law that the court upheld: a moratorium on future construction of nuclear plants in the absence of ''demonstrated technology'' for the disposal of highly radioactive nuclear waste. California has not found this condition met by controversial federal legislation for solving the disposal problem in the decades ahead. The Supreme Court cited a lower court's interpretation that the moratorium was adopted because ''uncertainties in the nuclear fuel cycle make nuclear power an uneconomical and uncertain source of energy.''
Not unexpectedly the court's ruling has been lamented or hailed as a setback to the nuclear power industry, which sought to overturn the California moratorium. The industry was joined by the administration in a departure from its support for states' rights.
Yet the nuclear industry has been virtually stalemated in recent years anyway. Both the industry and its administration backers can look beyond any setback and make renewed efforts for disposing of waste that is calculated to remain hazardous for generations. It has long been estimated that most operating plants could fill their on-site facilities for waste storage by the middle of this decade. Then, without a long-term solution, the question of transporting wastes around to other temporary sites would have to be addressed.
After many years without much federal progress, an interagency review group declared in 1979 that the responsibility for establishing a waste program should not be left to future generations. It stressed that public participation should be developed and strengthened in all aspects of the process. Indeed, a White House environmental official went so far as to advocate a federal moratorium on more nuclear plants until the public could be satisfied on the waste problem.
Now the Supreme Court has in effect given encouragement to such moratoriums state by state - and to speeded development of waste management credible enough to convince the public. Note that two justices in a concurring opinion said states should be able to ban plants for safety reasons, which have been the focus of most public concern, especially since the Three Mile Island accident. But the overall court ruling reserved the criterion of safety to the federal government and limited states to acting for economic reasons.
It was a high-level reminder of the economic issues that have been dogging nuclear power since those early days when it was heralded as a cheap-energy bonanza. Soon questions arose as to what the price of nuclear energy would be if it included such expenses as long-term waste disposal and the eventual decommissioning of contaminated plants. The cost of building plants soared. A few years ago a Harvard Business School study of energy reported views of coal power being much less costly than nuclear - and vice versa. Even after the multiplication of fossil fuel prices in the '70s, it was ''still plausible to assert that atomic energy is or is not competitive by a choice of assumptions that suits one's interest.''
What the public needs is a sense of certainty beyond a choice of assumptions. In the present uncertainty, states may go on blocking nuclear power for economic reasons unless Congress changes the law under which the Supreme Court says they are permitted to do so.