WASHINGTON/BOSTON (Reuters) - The disaster at a Japanese nuclear power plant is a chilling reminder that the U.S. nuclear energy industry has failed to solve a big problem -- where and how to store millions of highly reactive spent fuel rods.
For decades, power companies and regulators have put the issue in the "too hard" basket while the rods, which stay radioactive for many years, pile up around the nation's 104 nuclear reactors. The danger is that even the crisis at the Fukushima plant won't be enough to spur any major change.
"There's a lot of whistling past the graveyard on this," said Stephen Maloney, a risk consultant in Massachusetts who works with nuclear power companies.
Some executives are afraid to say publicly that the waste is too risky to keep in so many places and must be moved, he said.
In Japan, apparent water losses from a spent fuel pool helped to trigger fears of a large-scale catastrophe and likely led to a rise in radiation that permeated water and air near the plant.
It has led to a push from experts for a complete reevaluation of the risks taken in storing the rods.
"You can already see the progression of questions forming from the realization that in Japan the spent-fuel rods pose as great, if not a larger problem, as the fuel in the reactors," said Rod Ewing, a University of Michigan professor.
Any improvement in the storage system is likely to be more expensive, a potential deterrent if it makes nuclear power less competitive compared with electricity generated by burning natural gas or coal.
Meanwhile a more ambitious solution -- a plan to transport U.S. waste to Nevada for storage deep inside Yucca Mountain, a site about 100 miles northwest of Las Vegas -- could create additional new risks and has drawn stiff opposition from local residents, leading to it being shelved.
The U.S. nuclear industry, still the world's largest, has struggled with the storage problem ever since the first nuclear power plant was built in the 1950s.
New nuclear development in the United States ground to a halt after the Three Mile Island accident in 1979 but that hasn't stopped the existing plants from burning through many thousands of fuel rods since.
At the end of 2009 there were 218,853 spent fuel rod assemblies in storage in the United States, according to the Congressional Research Service. The number grows every year.
Assemblies like those used at the Fukushima plant typically contain between 80 to 100 fuel rods, which means that there are now millions of rods being stored around plants.
Of the total, only 49,121 assemblies were in dry casks or otherwise stored remotely, leaving the vast majority to lie in cooling pools like at the Fukushima facility. Rods can stand about 20 feet high and even a decade after use can emit enough radiation to kill a person standing nearby.
Storing more spent fuel rods in dry casks is one way to make them less vulnerable to natural disasters because they don't need constant power to keep fuel safe.
A critical factor that triggered the Fukushima disaster was the loss of the external power supply and the failure of the on-site backup system because of flooding caused by the tsunami. That may have allowed the cooling pools to overheat, reducing water levels and exposing the rods to the air.
But the casks, which hold about 10 tons of waste each, sell for about $1 million -- a cost that can be difficult to swallow for utilities.
And they are at best a partial solution.
Fuel rods are only cool enough to put into dry storage after five years in a pool -- which means that the most dangerous radioactive material must remain submerged. Secondly, there has been some concern that the dry casks stored in the open near some plants could make tempting targets for terrorists.
Some critics of the industry's safety, such as the Union of Concerned Scientists, say more use of dry casks may be the best short-term option for now, to move more fuel out of cooling pools.
"The national government has failed in its attempt to come up with any kind of coherent policy, and so as a result, all we can do is try to reduce the risk associated with this material until a better solution comes along," said Ed Lyman, a UCS senior scientist, on a recent press teleconference.
The waste issue goes beyond the power reactors. There is also a huge amount of nuclear waste at research reactors and at Department of Energy facilities.
Altogether, some 65,000 metric tons of waste uranium fuel is stored around the United States, with another 2,200 or so tons produced annually, according to the Nuclear Energy Institute, the nuclear power industry's trade group.
The U.S. industry had counted on the creation of the long-term waste repository at Yucca Mountain, which the federal government has already spent $10 billion to prepare.
But this plan was frozen by President Obama's administration last year amid opposition from local politicians, including his fellow Democrat Senate Majority Leader Harry Reid, and concerns about the site's proximity to fault lines.
Chart on US waste: <link.reuters.com/cut68r>
Map of US waste: <link.reuters.com/but68r>
FACTBOX-Nuclear waste storage in US [ID:nN23248218]
Yucca Mountain debate <link.reuters.com/mup68r>
The federal government is required by a 1998 law to take ownership of spent fuel, and utilities have already sued it for breach of contract for not taking charge of it.
They have won more than $2.2 billion so far in damages and the bill could reach $12 billion by 2020 without a permanent solution, according to the Justice Department.
The struggle over spent fuel has helped to define the industry for decades.
Connecticut's big Millstone nuclear plant was shuttered for several years in the mid-1990s after an engineer revealed to regulators how its operators were overloading a spent fuel pool to save time and money.
And after the September 11, 2001 attacks, U.S. officials ordered pool upgrades in case plants were hit and lost power.
To ease the pressure some Republicans have called for work to resume on Yucca Mountain. But even if Yucca was eventually approved it could take decades to move waste there from existing storage sites.
When the Obama administration stopped work on the site last year it also named a panel to study long-term nuclear issues.
In testimony before the commission in November a top nuclear executive, John Herron of New Orleans-based Entergy Corp (ETR.N), suggested moving used fuel to regional storage locations while awaiting a national plan.
The commission's co-chairman, former Indiana Democratic congressman Lee Hamilton, declined to discuss the panel's work in detail before its reports are issued. But in a telephone interview on Wednesday he said "the Japanese experience will certainly elevate the safety problem, not just for us (the panel) but the for the entire nuclear industry.",
The panel's challenge now is to come up with solutions that are palatable to Congress, power companies and the public.
"The tragedy of the U.S. nuclear issue is that the country has the world's best know-how on how to clean it up and keep it safe," said Thomas McMillen, the chief executive of Homeland Security Capital Corp, which does nuclear remediation.
"The panel might give us a road map, but fixing the waste issue is going to come down to the will of the nation," he said.
Reporting by Ross Kerber and Timothy Gardner; additional reporting by Scott DiSavino in New York; Graphics by Emily Stephenson. Edited by Martin Howell