METROPOLIS — Authorities have not yet determined the cause of a leak that released radioactive gas from the Honeywell International nuclear fuel processing plant in Metropolis which sent four residents to the hospital early Monday morning. No workers at the plant were injured.
Luis A. Reyes, administrator of the Nuclear Regulatory Commission’s regional office in Atlanta, said an alarm indicated there was a release of uranium hexafluoride (UF-6) from a valve in one of the plant’s chemical process lines at 2:24 a.m. He said UF-6 is a “potentially hazardous” chemical that contains low levels of radioactivity.
Honeywell spokesman Mark McPhee said Monday afternoon it has not been determined how much UF-6 was released during the leak, which was not brought under control for nearly an hour.
“If I lived in the area near the plant I would be somewhat frightened, to be honest with you,” McPhee said. “Police cars actually drove through the neighborhood with loudspeakers telling people to evacuate at 2:30 in the morning.”
The Metropolis plant refines raw uranium ore into the uranium hexafluoride gas, which is then shipped to other facilities to be further refined into enriched uranium rods that are used as fuel at nuclear power plants.
McPhee said some of the UF-6 gas did leave Honeywell property, but had little radioactivity.
“The uranium part of the product would not be visible once it hit the atmosphere. It would pretty much fall to the ground,” McPhee said. “The HF would actually form a vapor cloud and it would have been visible.”
Wind blew the gas cloud north from the plant and over subdivisions on Airport, Mount Mission and Country Club roads. McPhee said three of the four people who were hospitalized have been released; the fourth is being held for 24 hours’ observation.
“Some individuals went on their own,” he said. “The symptoms they were complaining of were sore throats, some of them had an odd taste in their mouths, some were coughing. Those are all symptoms of hydrofluoric acid inhalation.”
Ted Holder, chief deputy for the Massac County Sheriff’s Department, said his department will meet with Honeywell, as well as area fire departments and the state police, next week to review the emergency plan used during Monday’s leak.
“We (evacuated people) for about an hour, and then somewhere around 4 o’clock we were notified by Honeywell that we needed to keep people inside their residences instead of take them outside,” Holder said. “So we just stopped notifying people.”
Holder said Monday’s leak was the first he can remember that required evacuation of residents.
But the Nuclear Regulatory Commission said there have been other leaks in recent months. Leaks of gaseous hydrogen fluoride on Sept. 9 and uranium hexaflouride on Sept. 30 were contained on-site; a Sept. 12 leak of antimony pentafluoride, unrelated to the uranium processing, did escape the property.
McPhee said uranium processing at the Metropolis plant has been halted until investigators can determine the cause of the leak, which is thought to have been human error and malfunctioning equipment. He expects everything will be up and running later this week.
“If we’ve got some issues that we need to clean up here at the site, we’ll definitely do that and ensure that we are good neighbors again,” McPhee said.
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