During a routine refuelling operation at Chapelcross 3, a carousel holding 24 used fuel elements became dislodged from a grab within the de-fuelling machine.
The recovery operation took longer than expected, as the inside of the fuel discharge machine had to be inspected by remote cameras. Due to the delay, BNFL agreed to progressively shut down the other three Chapelcross reactors to focus resources.
Almost two weeks after the incident, BNFL confirmed that 12 rods were found in the transit flask that was located at the bottom of the discharge shaft, and 12 had remained in the defuelling machine. By this time only reactor 2 had been taken off line. Since all the rods could be accounted for, the incident could be formally declared closed and – with the agreement of the Nuclear Installations Inspectorate – reactors 1 and 4 could remain online.
The 12 rods in the shaft have been retrieved. Station manager Bob Clayton said: “Much work remains to be done, particularly to recover the 12 elements from the defuelling machine.” A full inquiry into the event is due to be carried out.
