[en] After giving a general description of ECCS and its woking and mentioning the factors on which its reliability is dependent, salient features of the ECCS of the Narora Atomic Power Project (NAPP) are described. Light water, instead of heavy water as in the Rajasthan Atomic Power Station, is to be used as an emergency coolant in NAPP, avoiding the possibility of moderator grade heavy water being mixed with primary heat transport system heavy water. Assuming that the recommended frequency of testing valves, switches and relays is adhered to, overall unreliability of the ECCS of NAPP comes to 0.9985x10^-2 which is within set permitted value of 10^-2. (M.G.B.)