U.S. Nuclear Plants Safer than Japan, but Work Remains
Nuclear reactors in the United States are safer than those in Japan, but there’s still room for improvement, according to speakers on The Council of State Governments Eastern Regional Conference’s webinar, Nuclear Safety in the Northeast.
The world has taken a second look at nuclear energy after an 8.2 magnitude earthquake and tsunami hit Japan’s Fukushima Dai-ichi Nuclear Power Plant on March 11, 2011. Three reactors had a meltdown, 20,000 to 25,000 people were killed or missing and 90,000 people were evacuated.
Although the plant survived the earthquake with its safety systems intact, the tsunami knocked out power to the plant, said Andrew Kadak, director of nuclear services for Exponent Engineering and Scientific Consulting. The loss of power meant water could not be pumped in to cool the reactors and ponds for used fuel rods. Three of the four reactors had hydrogen explosions, he said.
“It was a horrendous assault on a nuclear plant,” Kadak said. “Obviously, a nuclear plant is not designed to take those kinds of conditions.”
Previous brushes with disaster and tragedy have helped make America’s nuclear power plants more secure, Kadak said. The Three Mile Island accident in 1979, which led to a partial meltdown of one of the plant’s reactors, and the terrorist attacks of Sept. 11, 2001, led the Nuclear Regulatory Commission to strengthen disaster planning, including what to do in the event of power failure at a plant.
“In the U.S., we’re generally prepared due to 9/11,” he said.
David Lochbaum, director of the nuclear safety program for the Union of Concerned Scientists, said there are improvements to be made. The Northeast has 24 nuclear reactors in operation, and nine reactors that have been permanently shut down.
“Five (active) reactors in the Northeast don’t meet NRC fire protection regulations,” Lochbaum said. “Nationwide, about half don’t meet them. … Our recommendation is for the NRC to do more than to set fire protection regulations, but enforce fire protection regulations.”
Kadak noted that even though plants may not be compliant with current fire protection regulations, those regulations continue to change due to different interpretations of what compliance means.
“It does not mean utilities are not prepared to deal with a fire should it occur at a nuclear power plant,” Kadak said. “It’s not like there’s not fire protection at all.”
Lochbaum said reactors also are storing too many used fuel rods in water-filled ponds, usually located inside the main reactor building. After about five or six years in the pool—when the rods are their hottest—the rods can be moved safely to heavily encased steel and concrete containers called dry cask storage.
“What we believe should happen is, except for spent fuel rods discharged from the reactor in the last five or six years, all spent fuel should be moved from wet storage to dry cask storage,” Lochbaum said.
“By emptying spent fuel out, first of all, you’re replacing older fuel assemblies with water, so you have more water in the spent fuel inventory. If you lose water, … workers have more time to deal with that damage. If you’re not successful (in repairing any damage), because you have less fuel in the spent fuel pool, the size of the radioactive cloud is much, much smaller. … You’re lowering the probability (of an accident) and you’re lowering the consequences.”
Lochbaum said nuclear plant operators have been reluctant to fully embrace dry cask storage because of the costs associated with it. Federal law requires the U. S. Department of Energy to dispose of nuclear waste, but that still is not happening. Since 1983, states that generate nuclear power pay a tax to the federal government that is supposed to go toward developing a national repository. Although the fund now has more than $25 billion, nuclear waste continues to be stored at power plants and no national repository is in sight.
“The plants that have been decommissioned, the only hazard left is the spent fuel rods the federal government refuses to take,” Lochbaum said. “It’s the federal government’s fault, but placing the burden on plant and land owners isn’t the way to go.”