The disaster in the wake of Japan's March earthquake and tsunami has lawmakers wondering if we're storing spent nuclear fuel in a safe manner. But moving the waste from pools to casks carries its own risks.
A worker pointed to a monitor where a multipurpose canister was being removed last month from a spent nuclear fuel pool at the LaSalle County Generating Station, a nuclear power plant in Marseilles, Ill. Damage to Japan’s Fukushima Daiichi plant has raised questions of whether it’d be safer to store spent fuel in dry casks.
MARSEILLES, ILL. -- Watching intently as a huge white steel container surfaced from a 42-foot-deep canal, workers set upon it with long-handled tools, like sailors wrestling a flailing whale to the deck of a ship.
Yet this catch was far more menacing: 57,000 pounds of spent nuclear fuel at the LaSalle nuclear plant here, stored for decades in a pool and, if unshielded, powerful enough to deliver a lethal dose of radiation within seconds.
The fuel had just been moved into a capsule the size of a small silo, called a dry cask. Welded shut after it came out of the water, the cask was pumped full of inert gas, placed in an outer cask and moved outdoors to a concrete pad where it will sit until a disposal site is found. Spent fuel must be isolated from the environment for hundreds of thousands of years before it loses its potency.
The nuclear calamity at Japan's Fukushima Daiichi plant has refocused attention on the vulnerability of spent fuel pools at the 104 operating U.S. nuclear plants. The pools are generally far more packed than the damaged ones at Fukushima. Some scientists argue that the crowding raises the risk of a fire and makes the pools a tempting target for terrorists.
Several members of Congress are calling for the fuel to be moved from the pools into dry casks at a faster clip, noting that the casks are thought to be capable of withstanding an earthquake or a plane crash.
"We should not wait for an American meltdown to beef up American nuclear safety measures," Rep. Edward J. Markey, D-Mass., who advocates greater reliance on casks, said after the accident in Japan.
But transferring the fuel to dry casks involves risks, some industry experts warn. "Every time you move spent fuel, there's always a risk of human error," said Neil Wilmshurst, a nuclear power expert and a vice president of the Electric Power Research Institute, a nonprofit utility consortium. "How much of this do you want to do if you don't need to do it?"
The discussion is unfolding amid a far broader and more divisive debate over nuclear waste disposal. A half-century after the American nuclear industry was born, the nation still lacks a dedicated repository for such waste because of maneuvering driven by not-in-my-backyard politics.
In 1987 Congress designated Yucca Mountain, a desolate volcanic ridge in the Nevada desert, as a national disposal site, ruling out sites in Texas and Washington state. But the political landscape shifted, and the Obama administration canceled the project in 2009 under pressure from Sen. Harry Reid of Nevada, leader of the Senate's Democratic majority.
Then came the earthquake and tsunami in Japan in March, which cut off power to four reactors at Fukushima and caused three cores to melt. The melting fuel in the reactors released hydrogen gas that then exploded, throwing debris into the fuel pools, destroying a barrier that had prevented the release of radioactive materials to the outdoors and leaving the pools exposed to the rain.
Suddenly, the Nuclear Regulatory Commission was under pressure to explain whether crowded U.S. pools faced parallel risks.
Gregory B. Jaczko, chairman of the commission and a former aide to Reid, contends that both fuel pools and dry cask storage are relatively safe, with any differences being fractional. "It's like the difference between buying one ticket in the Powerball lottery and 10 tickets," he said in an interview, referring to the odds that something will go wrong.
But Robert Alvarez, a former senior adviser to the energy secretary and an expert on nuclear power, points out that unlike fuel pools, dry casks survived the tsunami at Fukushima unscathed. "They don't get much attention because they didn't fail," he said. Moving all the nation's fuel once it has cooled in pools for at least five years could cost $7 billion, Alvarez said.
Exelon Nuclear, operator of the twin-reactor LaSalle plant, says that it pays about $1 million for each cask and that loading each one with fuel costs another $500,000. It has filled six casks so far, and the concrete pad on which they sit outdoors cost the company another $1 million.
The assumption is that the fuel will remain in the casks for "years, maybe decades," said Peter Karaba, the plant manager. The fuel that was loaded the other day dates from the mid-1980s, when Karaba, 42, was still in high school.
Back in the 1960s, when most of today's reactors were designed, the consensus was that fuel would emerge from the reactors, cool for a few years in the pools and then go to a factory, where it would be chopped up. That process would take the unused uranium and plutonium created in the reactor's operation, purify them and fashion them into new fuel.
Although France and Japan do some of that recycling, Presidents Ford and Carter banned the practice in the United States for fear of encouraging a global trade in plutonium, a bomb fuel.
So U.S. utilities turned to casks, but only when fuel pools were close to capacity, as at LaSalle. Some industry specialists say that the policy should continue, partly to limit the risks posed whenever spent fuel is moved.
Industry experts acknowledge that working with casks poses some radiation risks. That is why several workers who gathered around the cask emerging from the pool at LaSalle wielded long poles with probes and Geiger counters; when they find an area of contamination, another worker with a mop on a long pole cleans it up.
Once the fuel enters a cask and has left the pool at the LaSalle plant, it joins others on a concrete pad a short walk from the reactor buildings. Maintenance is relatively simple. A worker checks twice a day to ensure that nothing is blocking the vents at the bottom of the outer cask so that air can circulate past the sealed steel capsule inside, carrying away the heat generated by the fuel.
Cask manufacturers anticipate decades of healthy demand. "I joke my children will be doing my job," said Joy Russell, a corporate development director at the manufacturer Holtec International.