Leak at Metropolis contained by sprays

27 October 2014

ORIGINALLY PUBLISHED: 3.30pm, 28 October 
UPDATE 1: 10.08am 29 October, with information from NRC statement

Honeywell's uranium conversion plant at Metropolis, Illinois suffered a leak late on 26 October which plant operators said was contained by prompt action including water sprays.

Describing the incident as an "on-site leak" of uranium hexafluoride (UF6), Honeywell confirmed to World Nuclear News in an emailed statement that the incident followed "an apparent equipment failure in the main production building." The Nuclear Regulatory Commission later said it was on the fourth floor of the plant's Feed Materials Building.

The Metropolis plant owned and operated by Honeywell. It converts uranium oxide powder into gaseous UF6 suitable for enrichment, which is then marketed by Converdyn, a joint venture of Honeywell and General Atomics. At atmospheric pressure UF6 is a solid below 56.6ºC.

Honeywell said the leak began at about 7.35pm on the evening of 26 October and plant personnel reacted immediately by activating emergency procedures and equipment. "The plant's trained emergency teams responded and contained the leak." The NRC said the leak was associated with a piece of equipment called the Primary Cold Trap. It was isolated and placed under vacuum, said the NRC, with another external vacuum placed nearby.

"At this point there are no reports of UF6 escaping the building and no sampling locations on the site outside the building detected any material," said the NRC. "There were no injuries and no indication that any UF6 material left the site," said Honeywell, noting that water sprays among other systems were activated to limit the progress of UF6 to "contain the materaisl in the area of the leak." The company said, "The water mitigation systems spray high volumes of water mist into the air and were the reason for the mist around the facility during the incident." Such sprays "knock down any hazardous gases," said the NRC.

Plant workers are investigating to find the amount of material released. The Nuclear Regulatory Commission confirmed it had been notified at the time of the incident.

Researched and written
by World Nuclear News