Isolation condensers (ICs) for removal of decay heat are immersed in the gravity driven water pool (GDWP). The pool is having a capacity of 6000 m3 of water and is divided into 8 symmetry sectors, each containing one IC. In normal operation the pool water circulates through heat exchangers to maintain the pool temperature. Figure III-1 shows the recirculation and cooling system of GDWP water. The decay heat generated in the reactor during shut down is stored in the form of sensible heat of water. However, stratification may influence heat transfer to pool to a great extent and heat storage capacity of the pool in the form of sensible heat is significantly reduced. The GDWP acts as heat sink for passive containment cooling system also (Fig. III-3).