Drips of liquid were observed from a valve flange on a condensate drain line from a ventilation duct which serves the Magnox fuel Reprocessing plant at Sellafield.
The drip was outdoors onto ground made up of a concrete slab and gravelled surface. The area was formally part of a Sellafield contamination controlled area but is now in an area free from contamination control. The area is, however, within the secure boundary of the facility. The condensate was sampled and confirmed to be contaminated with radioactive materials.
Precautionary access restrictions were applied to the 2 square metres area local to the contamination. Additionally, reassurance monitoring of construction workers who had used a nearby walkway has confirmed that they had not been contaminated. Monitoring also confirmed that no wider spread of contamination has occurred. Notification to the UK authorities occurred promptly as the amount was expected to exceed thresholds in Ionising Radiations Regulations. The event was initially rated INES 1 and re-rated INES 2 on 2009-05-11.