The crippled nuclear reactors at the Fukushima Dai-ichi nuclear plant in Japan are the same type and are of the same design as the single nuclear reactor at the Clinton nuclear site in DeWitt County.
The main difference between the two is that the containment structure – the protective enclosure around the nuclear reactor – is larger at the later-generation Clinton plant.
The Clinton station, operated by Exelon Corp., is located about 35 miles west of Champaign. Like the reactors at the troubled Japanese plant, it is a boiling-water reactor designed by General Electric. But it has a later-generation Mark III containment vessel. Twelve of the 104 nuclear plants in the United States use either a Mark II or Mark III containment system from General Electric.
Twenty-three others use the Mark I system that is the same containment system as at the damaged plant in Japan.
"One has more volume so it is better able to absorb more pressure," said Viktoria Mitlyng, a spokeswoman for the Nuclear Regulatory Commission.
In any case, a University of Illinois nuclear engineer said, central Illinoisans needn't be concerned about a similar disaster scenario here.
"I don't see where there's any need to be concerned about the plant at Clinton," said James Stubbins, head of the department of nuclear, plasma and radiological engineering at the University of Illinois. "I can't imagine that that set of circumstances could repeat itself here or almost anywhere."
The biggest problem, Stubbins said, is that after an earthquake shut down the reactor, a tsunami disabled the diesel generators at the site that were to have powered the pumps to cool the reactors.
"The real problem in Japan is that while the reactors were shut down safely, the issue is that the backup power for the cooling systems didn't operate," Stubbins said. "I don't see a scenario in which that could happen here. The backup diesel generators are tested all the time for these plants."
But David Kraft, director of anti-nuclear group the Nuclear Energy Information Service, said there have been problems with diesel-powered backup systems in the United States.
"Sure, we don't have tsunami capabilities and we don't have the same earthquakes, but if you don't fill your diesel generator tanks they're not going to operate," said Kraft at the Chicago-based NEIS. "Many reactors in the United States have received fines for emergency backup diesel generators that were inoperative. They would not have gone on if they had been needed. In one case, it was determined that the generators had been in that condition for five years."
Kraft accused the Nuclear Regulatory Commission of lax oversight of the industry.
"Who's watching this stuff? We have lost faith in the whole regulatory process here," said Kraft, who said he is a "self-taught" expert on nuclear power. "There is a total lack of real regulation."
Kraft said he also has concerns about the Clinton plant's proximity to the New Madrid Fault, which is centered in southeastern Missouri.
"We're on the fringes of the impact zone of the New Madrid Fault. So while we won't get a tsunami, the type of earthquake we get here in the continental interior tends to liquify the soil," he said. "It's sort of like having things put on Jell-O. So we don't know what that would do to the pools where the spent fuel rods are stored or the dry casks of fuel rods."
The biggest New Madrid earthquakes occurred in 1811 and 1812 and had estimated magnitudes of 7.0 to 7.7.
Kraft predicted the Japanese disaster could mean the death of nuclear power in the United States.
"The administration's so-called commitment to these new nukes, it's just a total waste of money. It's an energy source that should have dried up a long time ago. We really believe that this Japanese situation is the end of the nuclear age," he said.
Stubbins said it "could be a setback" but said the industry would emerge stronger.
"I think there's going to be a lot of thoughtful deliberation about what should happen in the future," he said. "Despite these kinds of things the nuclear power business has been very good about sharing information, and making a lot of effort to understand what faults could lead to what consequences. This kind of experience has been shared internationally."