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Emergency coolant tanks

The Emergency Core Cooling System (ECCS) supplies cooling water to the reactor during an interruption of the reactor’s normal cooling system. Upwards of 250,000 gallons of emergency make-up water is drawn from Refueling Water Storage Tanks (RWST) during the injection phase and from a containment sump during the second recirculation phase.


Level control of Refueling Water Storage Tanks is essential for emergency cooling operations. Low levels in these tanks can trigger actuation of pumps which bring additional coolant from accumulators, deaerators, de-mineralized water tanks, and treated condensate tanks. The ECCS can be tripped by an indication of coolant pressure loss or by low level of reactor coolant.

Consult factory for Nuclear Qualified instruments and specific model codes.