Lawmakers and policy planners must revive the search for safe ways to store used fuel rods from nuclear power reactors. The long-term solution favored by most experts, which we endorse, is to bury the material in geologically stable formations capable of preventing leakage far into the future.

But no politically acceptable site has yet been found, and leaving the used fuel rods at each reactor — more than 62,000 metric tons had accumulated across the country by the end of 2009 — seems increasingly problematic. At least nine states have banned the construction of new reactors until a permanent storage site is found or progress toward finding one is made. The only potential permanent storage site examined so far — at Yucca Mountain in Nevada — has been blocked for more than two decades by technical problems, legal challenges and political opposition from the state.

President Obama pledged in the 2008 campaign to shut down the project, and his Energy Department withdrew its application for a license before the safety of the project could be evaluated. Mitt Romney said in a primary debate in Nevada that the state’s people should have the final say. Even without a permanent disposal facility, the Nuclear Regulatory Commission issued a “waste confidence decision” in 2010 that asserted that used fuel rods could be stored at power plants for 60 years after they close down. It also asserted that a permanent repository would be ready to handle such wastes “when necessary.”

That decision was challenged in federal court, and last month a three-judge panel of the United States Court of Appeals for the District of Columbia ruled that the commission had failed to prepare an adequate analysis of the future risks, such as leaks and fires, if the used fuel rods end up being stored at nuclear plants indefinitely. That decision could slow the commission’s ability to extend the licenses of existing plants or grant new licenses.