Scientists and engineers suggest an interim fix is to store more spent fuel in dry casks, already a practice at many plants, although moving them to a remote central site would be better. Some of the casks are at retired or torn down reactor sites and require a high level of security.

South Carolina and Washington State, meanwhile, have sued the federal government, arguing that it has an obligation to accept the waste, some of which comes from the manufacture of nuclear weapons. On Tuesday, the United States Court of Appeals for the District of Columbia heard oral arguments in one case.

The not-in-my-backyard politics of nuclear waste have changed in recent decades. Congress chose Yucca Mountain over sites in Texas and Washington in 1987, when those two states were ascendant in the Capitol. The House speaker, Jim Wright, was a Texan, and so was the vice president, George Bush. The House majority leader, Thomas S. Foley, was from Washington State. Mr. Reid was a mere freshman senator.

Beyond the objections of Mr. Reid’s constituents to opening Yucca Mountain, it is not clear that it is a good place to bury nuclear waste. One problem is that the courts have interpreted federal law as requiring the Energy Department to show that the waste can be safely stored in canisters there for one million years. So far, the department has established only that it can contain the material for 10,000 years.

Examination of the mountain has also shown that if the fuel canisters degrade in millenniums to come, water would spread the waste faster than initially thought. Formed from volcanic material, the mountain’s rock was assumed to be barely permeable, but it has cracks through which water travels rapidly. In addition, the United States has about 72,000 tons of spent fuel from civilian sites and many tons of military waste — more than Yucca could hold under current laws.

In moving to withdraw the license application for the site last year, President Obama appointed a special panel to explore nuclear waste disposal, and a preliminary report is due in a few weeks.

The panel’s members have not been asked to propose a specific site. Instead, they are examining issues like whether the spent fuel should be chemically recycled to recover plutonium produced in uranium-powered reactors for reuse, as it is in France and Japan. Another option is to develop a new class of reactors that would transmute nuclear waste into less troublesome materials.