Fuel handling operations are dominated by the radio­logical safety of the operators and the public. Op­erations, both manual and automatic, must be se­quenced so that each step is monitored and correctly completed before the next step starts and other op­erations are locked out. This requires an extensive and complex control/interlock system with mechanical baulks and a multitude of microswitches showing equipment component position, together with mea­surement of parameters such as hoist loads. However, malfunctions must be expected. No malfunction must lead to a radiological hazard. Recovery must be pos­sible by interlock over-riding and handwinding when applicable.

Radiological shielding and pressurisation severely restrict the ability to see what is going on. Periscopes, TV cameras and shielded windows provide limited viewing for normal and recovery operations.