There are 104 commercial nuclear reactors operating in the United States, about a quarter of the world's total. They produce no greenhouse gas emissions while producing nearly 20 percent of the nation's electricity, making them a key ingredient in meeting power demand while fighting global warming.

The fundamental obstacle to more effective use of the technology, especially with the advent of new reactor designs, is the question of what to do with radioactive waste.

The current system - onsite storage of nuclear waste at 80 different sites around the country, for lack of anyplace else to put it - probably is among the least safe of all options. But the safest option, single-site storage in the repository at Yucca Mountain, Nev., can't be used due to radioactive politics.

Though President Obama has said he favors nuclear power as one means to fight global warming and central storage of waste at Yucca Mountain, he appointed Gregory Jaczko to head the Nuclear Regulatory Commission soon after he took office.

Mr. Jaczko is a former staffer of Senate Majority Leader Harry Reid, the Nevada Democrat who opposes the Yucca Mountain repository site. In 2010 Mr. Jaczko stopped work on a permit application for Yucca Mountain that had been submitted by the Bush administration in 2008.

Two weeks ago the U.S. Court of Appeals for the District of Columbia called Mr. Jaczko's action what it is: illegal. The role of the technical experts at the NRC is to weigh the merits of each application, not to rule on decisions by Congress, which designated Yucca Mountain as the nuclear waste repository in the Nuclear Waste Policy Act of 1982, and has funded its implementation every since then.

Now Congress should fully fund established of the repository for the 70,000 tons of spent nuclear fuel now held on-site at scores of power plants.