Cameco has taken satisfactory corrective actions following an incident at its Key Lake Mill in February, which involved a leakage of uranium dust from an exhaust duct in the building, the Canadian Nuclear Safety Commission said yesterday.
In an incident report on its website Cameco said that on 16 February, contractors installing piping on the fourth floor of the yellowcake building reported dust in their work area. This was later identified as calcined uranium ore concentrate (UOC) from failed weld seal connecting two sections of a duct.
Cameco determined through uranium-in-urine testing that one worker had an intake of calcined UOC, which resulted in a weekly effective dose of 1.16mSv, exceeding the weekly action level of 1mSv. But two other workers who were potentially exposed did not receive a discernable dose from the incident.
In response to the incident, operations were halted at the Key Lake mill to repair the duct. Cameco started an investigation and developed a plan to safely repair the duct. This has now been completed.
The CNSC said, 3 March, that its staff have inspected the facility, reviewed Cameco's initial reports, and are satisfied with the corrective actions taken to date. The event is due to be discussed at a public commission meeting on 25 March.