More context 15:30 Aug 11, 2016
The isolation condensers were used in older boiling water reactors to remove decay heat from the reactor core at high reactor coolant pressure when the main condenser was not available. The design of the IC was not part of the emergency core cooling system (ECCS). The IC isolation logic is similar to the logic for other piping systems which are not required for postulated accident mitigation and which penetrate the primary containment and are also connected to the RPV, such as the main steam lines and their associated main steam isolation valves (MSIVs). Because these isolation logic circuits are powered by the DC power systems, an isolation signal is generated upon the loss of DC power to the logic circuits, taking into account that such an event results in the loss of the ability of the logic circuits to monitor for a pipe break or coolant leak. |