Spent nuclear fuel stored onsite at commercial nuclear reactors in the U.S. will increase by about 2,000 metric tons per year and balloon to more than 140,000 metric tons by 2055, before it can be moved offsite when storage or disposal facilities are expected to have been developed, the Government Accountability Office (GAO) found in a recently released report.

The outlook is "challenging," the congressional investigative arm says in its report titled "Accumulating Quantities at Commercial Reactors Present Storage and Other Challenges," because centralized storage or permanent disposal options could take as long as 15 to 40 years to build—longer than the lifetimes of most U.S. reactors—and even when they are ready, it will take several more decades to ship spent fuel to these facilities.

Nevertheless, risks associated with storing spent nuclear fuel—particularly a self-sustaining fire in a drained or partially drained spent fuel pool—could have widespread implications, the 66-page report noted. About 74% of commercial spent nuclear fuel stored at reactor sites today is stored in pools of water, and 26% has been transferred to dry storage casks. With efforts to license Yucca Mountain, a proposed underground permanent waste repository, separately suspended by the Nuclear Regulatory Commission (NRC) and Department of Energy (DOE) in 2010 and 2011, nearly 70,000 metric tons of spent fuel are currently being stored in 33 states.

But even if licensing for Yucca Mountain were to be resumed in 2012, the GAO projected that the DOE would need at least 15 more years—until sometime around 2027—to open the site as a repository. Federal siting, licensing, and construction of two centralized storage facilities could take 20 years, with completion in 2032, and development of a permanent disposal facility as an alternative to Yucca Mountain could take about 40 years, with completion in 2052, owing to decades of studies to ensure it was safe.

Estimates that 140,000 metric tons of spent fuel will accumulate by 2055 is a conservative estimate, the GAO noted, pointing out that it was assumed no new reactors would be brought online and some decline in the generation of spent fuel would take place as reactors were retired.

"Resolving the issue of what to do with commercial spent nuclear fuel will likely be a decades-long, costly, and complex endeavor," the report said. "Planning ahead to allow reactor operators and local communities to make better-informed and forward-looking decisions is important in such a complex undertaking."

Several lawsuits have been filed to force the NRC to resume licensing proceedings for Yucca Mountain, and at least 76 other have been filed against the DOE by utilities that claim the federal agency did not take custody of the spent fuel starting in 1998 as required by the 1982 Nuclear Waste Policy Act. The delays are proving costly, the GAO noted: Lawsuits against the DOE have to date cost taxpayers $1.6 billion from the U.S. Treasury’s judgment fund, while the DOE estimates future liabilities will total an additional $19.1 billion through 2020, and $500 million per year after that.

One option to temporarily resolve the nuclear waste conundrum is to transfer spent fuel from wet to dry storage, the GAO said. This has costs and risks—including those associated with moving it—but it would allow safe storage of spent fuel for decades after nuclear reactors retire. However, the length of time that spent fuel can be safely stored in dry casks is "uncertain," the report noted. Though experts say it can safely be stored for about 100 years, an NRC determination in December 2010 stated that spent fuel can be stored for up to 60 years beyond the licensed life of the reactor in a combination of wet and dry storage.

In a landmark decision, a federal appeals court this June remanded that determination back to the NRC, saying it lacked a necessary environmental impact statement. The NRC later this August voted not to issue final licenses dependent on the determination until it could address the court’s remand. The agency is meanwhile preparing an environmental impact statement on the effects of storing spent fuel for 200 years.

The report was compiled in response to queries from unnamed congressional requesters, who asked the GAO to examine how much spent fuel was expected to accumulate before it could be moved from reactor sites around the country, what safety and security risks were associated with storing spent fuel onsite, and how beneficial or challenging it was to transfer spent fuel out of wet storage and away from reactor sites.

It was released as the Senate Committee on Energy and Natural Resources last week held a hearing to discuss a nuclear waste management bill (S.3469) sponsored by retiring committee Chair Sen. Jeff Bingaman (D-N.M.). While senators from both parties agreed on most parts of the bill, including recommendations from the Blue Ribbon Commission (BRC) on how to handle the nation’s nuclear waste, disagreements arose on how nuclear waste should be dealt with in the interim. Democrats asked that an application for a permanent storage site be filed before moving waste to consolidated interim sites, as is required by the bill, but Republicans said the process would be caught up in bureaucratic red tape.

The only utility representative testifying at the hearing, Constellation Energy Nuclear Group CEO Henry Barron told lawmakers that though the proposed bill was a "positive start to overhauling the federal program, it does not provide the comprehensive changes that are needed." Barron lamented that more than $34 billion had been committed by nuclear power consumers since 1982 to the Nuclear Waste Fund for a permanent spent nuclear waste solution, and that the DOE continued to collect more than $750 million every year from consumers even though it "without any technical basis" terminated Yucca Mountain in 2010.

Consolidated storage was the "quickest route for the federal government to begin moving used fuel from nuclear energy facilities and to stem the increase in damage awards beyond the estimated $20.8 billion through 2020," he added. As well as the industry and the BRC, the National Conference of State Legislatures; the governors of Maine, Maryland, Pennsylvania, and Vermont; and many other organizations and political leaders have all publicly called for action to implement the BRC recommendations and, specifically, development of a consolidated storage facility, Barron said.

Sources: POWERnews, GAO, NRC, DOE, Senate Committee on Energy and Natural Resources

—Sonal Patel, Senior Writer (@POWERmagazine)