Despite a general consensus that highly radioactive spent nuclear fuel should be stored in underground repositories, finding appropriate sites for such repositories has been so politically fraught that none exist worldwide, panelists at a AAAS-organized Capitol Hill briefing explained.
With about 240,000 metric tons of spent nuclear fuel in storage at the end of 2009 and approximately 10,500 tons of spent fuel generated annually, the need for a long-term solution for spent fuel storage is growing quickly.
“The primary problem with siting repositories is not actually area,” said M.V. Ramana, an associate research scholar at Princeton University. “It’s not the cost of the real estate that’s going to be stopping the process. It’s the political challenge of trying to find a community that’s willing to live with this hazardous stuff for hundreds of thousands of years.”
Thirty countries with nuclear power plants are in various stages of determining their long-term strategies for spent fuel disposal, said Frank von Hippel, co-chair of the International Panel on Fissile Materials (IPFM), an independent group of non-proliferation and arms-control experts from 17 countries.
Plans by the Obama administration to scrap a proposed spent-fuel repository at Yucca Mountain inspired a forthcoming IPFM study, von Hippel said. The study was discussed at a 3 June briefing on Capitol Hill hosted by the AAAS Center for Science, Technology and Security Policy. A draft summary of the study was released at the briefing.
After being unloaded from power reactors, spent nuclear fuel is immediately placed in water-filled pools on the reactor site to allow heat and radiation levels to decrease over several years or even decades before further disposition.
But, said von Hippel, “a large fraction of the pools are full and nobody has a repository yet and they have to figure out what to do.” The result: An increase in temporary storage in dry casks, which are steel canisters surrounded by reinforced concrete. About 90% of the world’s spent fuel is stored in pools while the remainder is above ground in such casks.
At the end of 2010, the U.S. had 64,500 tons of spent fuel, significantly more than any other country. According to the report, Congress selected Yucca Mountain, Nevada, for a repository site in 1987, and the Department of Energy has spent about $15 billion since then preparing the technical basis for a license application for the site.
But “Nevada didn’t want it,” von Hippel said. “Nevada pushed back and then the political situation changed.” Facing pressure from Nevada’s state government and congressional delegation, as well as continuing technical questions about the suitability of the site, the administration of President Barack Obama halted work on Yucca Mountain in 2010.
Yucca Mountain was only the most recent example of what was termed by the group the “DADA approach,” in which officials decide on a repository site, announce the location, defend their choice, and ultimately abandon the idea. “In ’86, there was a drilling done quite close to Stockholm and the national media were there and you had the TV showing old-age pensioners being dragged away with the police and police dogs,” said Johan Swahn, director of the Office for Nuclear Waste Review, a non-governmental organization in Sweden. The government was forced to change course.
Sweden later adopted a voluntary plan for choosing repository sites, Swahn said. In the end, two communities volunteered to host a repository and one was chosen. The licensing application for the new geological repository next to the Forsmark nuclear power plant was submitted in March.
“Germany started quite early thinking about options of nuclear waste disposal,” said Beate Kallenbach-Herbert, head of the Oeko Institute’s Nuclear Engineering and Facility Safety division. However, the only spent-fuel disposal option in Germany currently is on-site dry cask storage. Following the tsunami-triggered accident at Japan’s Fukushima Daiichi nuclear plant, the German government announced 30 May that it would shut down eight of the nation’s 17 nuclear power plants immediately and shut down the rest by 2022.
Some countries have sent spent fuel to France or the United Kingdom, where reprocessing plants dissolve the fuel and allow uranium and plutonium—which can be recovered and potentially even reused—to be separated from the rest of the high-level radioactive waste. But this does not eliminate the waste problem, since both the waste and the recovered uranium and plutonium are sent back to the country of origin.
But even reprocessing has drawbacks, said Ramana, who is also an IPFM member. It concentrates the radioactivity in spent fuel “in the form of high-level waste and that produces a lot of heat,” he said, “and the size of your repositories are largely determined by how much heat is generated.” If the plutonium that is recovered through reprocessing is used to fuel reactors, then that would have to be eventually disposed of as well. When all these wastes are considered together, the amount of space required for a repository is “not going to change very much” compared to the difficulty of disposing of spent fuel that has not been reprocessed, he said.
Von Hippel agreed. “Reprocessing doesn’t help politically—or technically, for that matter—at reducing the waste problem or making it easier to site for a repository,” he said.
Meanwhile, Russia had been one of the few countries willing to take back spent fuel from other countries, said Pavel Podvig, an analyst of Russia’s nuclear policy and IPFM member. Rosatom, the Russian nuclear power agency, considered its willingness to take back spent nuclear fuel as a competitive advantage when selling new reactors, a strategy that appeared to have helped it in Turkey. But it turned out that the Russian public strongly opposes taking back spent fuel that was not originally supplied by Russia, so Rosatom was forced to announce that it would never bring foreign-origin fuel to the country.
In the U.S., storage pools were initially designed to hold spent fuel for five years, von Hippel said, but they’re storing much more fuel for a longer period of time. He said that storing fuel older than five years in dry casks would “reduce the hazard,” but by “an unquantifiable amount.” Moreover, the cost associated with dry cask storage is relatively low. “We’re talking about hundredths of a cent per kilowatt hour,” von Hippel said.
Still, the U.S. Nuclear Regulatory Commission has maintained that the hazards posed by densely-packed spent fuel pools don’t justify the cost of transferring the spent fuel to dry casks. It remains to be seen what the impact of the Fukushima accident will have on that assessment.
An interim report by the Blue Ribbon Commission on America’s Nuclear Future, established in January 2010 by the Obama administration, is expected in July.
21 June 2011