ACCIDENT OPERATING CONDITIONS .
Emergency core cooling.

Recirculating the coolant..

The coolant injected into the core flows away through the leak and is collected into the sump; as the leak may last weeks or even months, the coolant must be recirculated, in the attempt to cool down the core.

The recirculation just transfers the heat from the reactor to its containment; additional actions are required to remove the heat from the containment; this is the purpose of the emergency spray.

The outcome of the emergency cooling operations can hardly be predicted, because during upset operating conditions many events may jeopardise the planned actions; for instance, strainers may become jammed or loose parts may damage pumps or valves...

Many devices related to the emergency operations are located outside the reactor containment and the risk of a radiation leak cannot be ruled out