After the heat transport system is crash cooled and the loops of the HTS are isolated automatically by the LOCA signal (see discussion for broken loop above), the CMTs replenish the inventory of the intact loop and limit the extent and duration of voiding that occurs.

When the HTS is full and free of void, natural circulation can be relied upon to remove heat from the fuel (see Section II-2.1). This is supported by provision of feedwater to the secondary side of the steam generators as a heat sink. Feedwater is supplied from either the main or emergency feedwater systems. Feedwater may also be supplied from the RWS, though this make-up must be initiated manually.