July 10 (Bloomberg) -- Storing nuclear waste above ground at atomic power plants for as long as six decades may be the best temporary solution in the U.S. for the dangerous refuse, university researchers say.

Leaving spent fuel on the site after the stations close may be the most viable and “safe, short-term option,” University of Michigan researcher Rodney Ewing and Princeton University’s Frank von Hippel wrote in Science. In the longer term, the U.S. will need several geological dumps, von Hippel said in yesterday’s report.

Radioactive waste, which is dangerous for thousands of years, is stored temporarily near the reactors that generate it in countries including Spain. There is no permanent solution in sight. In U.S., which has about 60,000 tons of spent waste from power plants and weapons and produces an additional 2,000 tons each year, the material is now spread among more than 120 sites in 39 states, according to the Energy Department.

“Most people don’t realize what a difficult situation we’re in,” Ewing said in a podcast on Science’s Web site. “It looks like the United States is starting over with its nuclear waste management policy. In the end, we need to have alternatives.”

A permanent location to store the spent fuel was dealt a setback after President Barack Obama rejected a plan to develop Yucca Mountain in Nevada as a repository. The decades-long project cost at least $9 billion and was the only spot considered for long-term storage of the dangerous material.

An alternative to a single site would be developing dumps in different parts of the country, reducing transport costs as well as creating a safety standard for all potential underground repositories to contain radioactive refuse to be overseen by the Environmental Protection Agency, the authors said.

Cooling Spent Fuel

There are two ways at present to cope with radioactive waste. One is to cool spent fuel in pools until the radioactivity diminishes, then place it in underground storage, something the U.S. does not possess and the pools are filling up. Another option includes storing the material in dry-casks, which is not an acceptable long-term solution, Ewing said.

Any “sensible plan” to deal with waste has to include moving the radioactive materials out of the temporary pools and into dry-cask storage, Ewing said. That waste would then eventually be moved again into the long-term repositories.

Most people who advocate expanding the use of nuclear power should expect that the radioactive waste will likely be stored locally at the plants, Ewing said. There are 104 operating commercial reactors in the U.S., and 17 applications are pending at the Nuclear Regulatory Commission to build 26 more reactors.

To contact the reporter on this story: Jeremy van Loon in Berlin at jvanloon@bloomberg.net.

Last Updated: July 9, 2009 19:41 EDT