Tank That Leaked Toxic Gas Was Reported Overfilled
WEBBERS FALLS, Okla. (AP) _ A chemical tank at a nuclear facility was too full when it cracked and leaked 141/2 tons of radioactive gas, killing one man and hospitalizing dozens who breathed potent acid fumes, authorities said Sunday.
Saturday’s leak at a plant that processes uranium fuel sent a cloud of poison gas as far as 18 miles. More than 100 people were treated for exposure to the gas, and Interstate 40 was closed for two hours as the cloud dissipated.
On Sunday, six federal investigators were at the Sequoyah Fuels Corp. plant, which remained closed. Twenty-six people hospitalized overnight were released while eight remained hospitalized in stable or good condition. All but nine of those admitted were plant workers.
The leak of uranium hexafluoride apparently occurred after a cylinder was accidently overloaded, said Dick Bangart, director of the Division of Radiation Safety and Safeguards for the Nuclear Regulatory Commission.
″For this kind of facility, this is one of the most severe accidents that they can have,″ he said.
The cylinder, designed to hold 27,500 pounds of the mildly radioactive material, was filled with 29,500 pounds before employees realized they had improperly placed it on a scale, Bangart said at a news conference in Muskogee.
Workers heated the cylinder in an attempt to remove the excess gas, Bangart said. The container then ruptured and all the gas spewed out.
The employee who died was on a platform above the cylinder and downwind of the poison plume, Bangart said.
″It took him such a length of time (to escape the cloud) that he could not avoid (overexposure),″ he said.
The gas had a nauseating odor and ″your throat burned,″ said Bill Kassinger, 38, an electrician for a construction company working on an expansion at the plant.
Sequoyah officials could not be reached for comment despite repeated attempts. A secretary said Donna McFarland, a spokeswoman for parent company Kerr McGee Corp. of Oklahoma City, was too busy to talk to reporters Sunday afternoon.
Ms. McFarland said Saturday the plant would not resume uranium processing until the NRC and other agencies, including Kerr-McGee, complete their investigation.
Six NRC technicians were at the site Sunday, and an expert on structural analysis was expected.
Joseph Fouchard, spokesman for the NRC in Washington, D.C., said he did not know if it was the first death from the making of uranium reactor fuel, but said there had been other deaths in the industry since it began in the 1940s with the Manhattan Project.
When released into the atmosphere, uranium hexafluoride breaks down into hydrogen fluoride and slightly radioactive uranyl fluoride particles, Ms. McFarland said Saturday. Toxic hydrogen fluoride combines with moisture in the air to form hydrofluoric acid, which is strong enough to etch glass.
″We have absolutely no evidence of radioactive exposure,″ said Dr. Michael Herndon, an emergency room physician at Sequoyah Memorial Hospital in Sallisaw.
Uranium hexafluoride produced at the plant, 40 miles from the Arkansas border, sent to a facility operated by the Department of Energy where it is enriched by increasing the percentage of fissionable isotopes. The enriched gas is changed into solid uranium oxide to be made into reactor fuel elements for nuclear power plants, said Gary Sanborn of the NRC in Arlington, Texas.
Authorities said the gas cloud dissipated in 20 mph wind about two hours after the 11:45 a.m. leak was reported.
Dale McHard, chief of the radiation and special hazards service of the state Department of Health, said soil and vegetation samples indicated the acid cloud may have traveled as far as 18 miles south of the plant before it dispersed. He said effects were expected to be temporary.
Only one person lives within a half mile of the plant and fewer than 20 homes are within two miles, McHard said.
The gas breaks down so fast that ″if you lived more than a half a mile away there was little danger,″ said Dr. Carl Bogardus, director of radiation therapy at the University of Oklahoma and a consultant to Kerr-McGee.
Ed Henshaw, who formerly worked at the plant, said he could see the cloud when he was about a quarter-mile away. ″It looked like a cloudy, white haze on the ground,″ he said.
He called the accident ″a short-term accident - just one of the risks of living with one of these plants.″
″You know the plant is there, and you fear it, but you can’t dwell on it,″ said Lorene Thomason, who lives with her husband about a mile from the plant.
A spokeswoman at Sequoyah Hospital said 102 people were treated in the emergency room for exposure to hydrofluoric acid. Exposure to the gas causes irritation to the eyes, skin and respiratory system, Herndon said.
Of the 34 people admitted to the hospital Saturday, 25 were plant workers.