Canada's sole uranium conversion plant is offline pending an investigation by regulators into an unplanned shutdown last week.
Cameco, which owns the Port Hope Conversion Facility, reported that the uranium hexafluoride plant was in operation during the installation of safety-related software Jan. 28. The company told the Canadian Nuclear Safety Commission that a hydrogen recirculation valve for a cell room did not respond as expected, resulting in multiple cells being drawn into a vacuum state. Some cells lost H2 and F2 gas separation, resulting in recombination of the gasses, and cell electrolyte might have been pulled into the headers, according to the CNSC. Shutting the plant down required manual action by operators, and regulators have asked the plant to investigate why intervention was necessary after an emergency stop button was pushed in the control room.
The plant, one of only four of its kind in the western hemisphere, will remain offline pending a root cause analysis and a satisfactory response to the CNSC. No worker exposure resulted and no radiation was released into the environment, but the agency is considering the event "a loss of control within the facility, with the potential to create unsafe conditions."