Reactor condition controlled check valve permits coolant to flow from a reservoir to an isolation condenser chamber

A nuclear reactor system for commercially generating electricity, the system comprising:

• a nuclear reactor;
• at least one primary coolant loop connecting to the nuclear reactor;
• and
• an isolation condenser system connecting to the nuclear reactor, wherein the isolation condenser system includes
• at least one isolation condenser in a coolant chamber, wherein the isolation condenser includes a heat exchanger and is configured to transfer heat from a reactor coolant to the coolant chamber,
• a coolant pool,
• a flow path between the coolant pool and the coolant chamber, wherein the flow path is openable and closeable to connect and isolate the coolant pool and the coolant chamber, and wherein the flow path includes a check valve preventing coolant flow from the coolant chamber to the coolant pool,
• a switch configured to determine relative coolant level between the coolant chamber and the coolant pool and operate the check valve based on the relative coolant level,
• an inlet line connecting the nuclear reactor to an entrance of the heat exchanger, and
• an outlet line connecting an exit of the heat exchanger back to the nuclear reactor, wherein the entrance is vertically above the exit.