November 6, 2001
SAN FRANCISCO, Calif. (Reuters)–While the United States steps up security at its nuclear power plants, energy experts warn the plants’ fuel dumps are far more vulnerable than reactors to attack by anyone trying to spread radioactivity.
“Spent fuel has never gotten the same attention as the reactor … as a result you don’t have the same level of security and safety as exists for the reactor,” David Lochbaum, a former nuclear plant engineer now with the Union of Concerned Scientists, told Reuters.
“Because it’s a softer target and has greater consequences, terrorists may elect to go after the spent fuel,” he said.
Security has been tightened at the 103 nuclear power plants in the United States, the source of 20 percent of the country’s electricity, since the Sept. 11 hijacked plane attacks that killed about 4,800 people in New York and the Pentagon.
Amid U.S. calls for increased vigilance at strategic sites worldwide, the head of the Vienna-based International Atomic Energy Agency warned on Thursday that an act of nuclear terrorism was “far more likely” than previously thought.
Since Sept. 11, much of discussion in the nuclear industry has focused on whether an aircraft could penetrate the steel and concrete containment building surrounding a plant’s reactor.
But nuclear experts are warning that guarding on-site storage facilities for these same reactors’ highly radioactive spent fuel is also a critical issue that must be addressed.
The Nuclear Regulatory Commission, which oversees the U.S. nuclear industry, needs to devote more attention to this issue, agency spokesman Victor Dricks said.
DE FACTO WASTE DUMPS
When most of the energy is wrung from the radioactive pellets used to run the power plants, the spent fuel is tightly sealed in water-filled, on-site pools. Water is needed to cool the fuel, which gives off heat and radiation for many years after it is removed from the reactor.
Over the years, the pile of spent fuel from U.S. reactors has grown to more than 40,000 metric tons, enough to bury a football field under 15 feet of waste material, the Washington-based industry group Nuclear Energy Institute said.
About two-thirds of this fuel is kept in underground pools, which provide far better containment than for the third stored in above-ground buildings.
But most of these pools are housed in far less robust structures than the reactor containment vessels, which are designed to contain the equivalent of a small nuclear explosion should things go badly wrong in the reactor core.
Though the walls of waste storage pools are thick, reinforced concrete lined with steel, the roofs are made of “pretty insubstantial material” like sheet metal, Lynnette Hendricks, director of licensing at Nuclear Energy Institute, told Reuters.
And while the pools lie within high security areas, there are fewer locked doors and safety barriers between spent fuel and the atmosphere than surrounds the fuel in the reactor.
Another concern is the vulnerability of the pools’ cooling systems. “If you knock out that system, there are no automatic back-up systems,” Lochbaum said.
If the water boils or drains away, the discarded fuel would overheat, either melting or catching fire, threatening to release a radioactive cloud.
The pools, initially designed as temporary containers, can withstand earthquakes, tornadoes and other natural calamities, but were not built to withstand acts of sabotage.
“The pools are not designed to withstand the impact of a jetliner, but they are relatively small … it would be extremely difficult for an aircraft, even if deliberately targeting one, to hit one,” said Dricks of the Nuclear Regulatory Commission.
When most of the country’s nuclear reactors were designed in the 1960s and 1970s, it was assumed their radioactive waste would be shipped off to a central repository or reprocessing facility.
But commercial reprocessing was never successfully developed in the United States, and plans to open a permanent disposal site in Nevada have already been delayed 12 years until around 2010 — if it opens at all.
While legislators, power companies and environmentalists squabble over what to do with the spent fuel, storage space in the temporary facilities gets ever more crowded.
“Now (pools) hold considerably more (spent fuel) than in a reactor,” said Gordon Thompson, a nuclear scientist and executive director of the Institute for Resource and Security Studies, an independent think tank based in Cambridge, Massachusetts.
It only takes about five to six years of operation for a power plant to produce more nuclear waste than it holds in its reactor, and the biggest of these pools now holds seven to eight times as much fuel as in a reactor, said Lochbaum of the Union of Concerned Scientists.