WASHINGTON — The worker who died in a gas leak at an Oklahoma nuclear fuel plant was killed by a lethal dose of acid, not radiation, a Nuclear Regulatory Commission official said Monday.
Richard Cunningham, NRC safety division director, said James Harrison and five other workers at the Kerr-McGee plant in Webber Falls also may have inhaled "a small amount of uranium," but their burns and respiratory distress were caused by chemicals.
Two of the five workers remained hospitalized Monday.
The uranium that leaked from a ruptured cylinder Saturday "is very heavy and plates out (solidifies) too rapidly to be ingested in an accident like this," Cunningham said on the "CBS Morning News." Nonetheless, he said, doctors are examining injured workers' kidneys for damage from uranium exposure.
Investigation's Key Point
The cylinder rupture is the key point in the agency's investigation of the accident, Cunningham said.
"It's still not at all clear what caused the accident," he said. "We don't know if the rupture was caused by heat or fatigue in the steel that succumbed to the excess weight."
The stainless steel cylinder, about the size of a small car, was one ton overweight, officials said. Plant workers were heating the cylinder to expel the excess gas when it broke open.
"There was no fire and no big bang, but the cylinder's contents came out fast enough to react quickly with the atmosphere to form lots of hydrofluoric acid," Cunningham said.
He added that workers failed to follow normal procedures when they unloaded the tank of uranium hexafluoride gas.
Unusual Problem, Answer
Donna McFarland, a Kerr-McGee spokeswoman, said heating the tank was an unusual answer to an unusual problem--accidental overloading.
Officials said the Kerr-McGee plant, which is operated by Sequoyah Fuels Corp., a subsidiary, would be closed for up to one week for cleanup.
An NRC team is supervising removal of tainted topsoil at the plant and scrubbing of asphalt surfaces including nearby Oklahoma Highway 10.
Meanwhile, an anti-nuclear group in Washington warned that the Nuclear Regulatory Commission might prematurely weaken safety guides because of research reports that reduce estimates of the amount of radioactivity that could escape during a severe power plant accident.
The Union of Concerned Scientists expressed its concerns in a report to be filed with the commission today.