A passive containment cooling system (PCCS) condenser, for reducing some non-condensable gases in the PCCS, includes a first and a second stage condenser that each include channels in fluid communication between an inlet and an outlet header. The inlet header of the first stage condenser is configured to receive a fluid mixture through a first inlet opening. The channels are configured to condense water from the fluid mixture flowing through the channels from the inlet header to the outlet header, respectively, of the first and second stage condenser. The PCCS condenser includes a catalyst in at least one of the outlet header of the first stage condenser or the inlet header of the second stage condenser. The catalyst catalyzes a reaction for forming water from hydrogen and oxygen in the fluid mixture. The outlet header of the second stage condenser is in fluid communication with a combined vent-and-drain line.

A depressurization and cooling system for steam and/or condensable gases located in a containment. The system contains a steam condenser having an upstream port connected to the containment through an exhaust line and a downstream port connected to the containment through a backfeed line. The backfeed line contains a backfeed compressor. A re-cooling system for re-cooling the steam condenser is provided. The depressurization and cooling system is effective for re-cooling of the steam condenser. Accordingly, this is achieved as the re-cooling system is self-sustainable.

A depressurization and cooling system for steam and/or condensable gases located in a containment. The system contains a steam condenser having an upstream port connected to the containment through an exhaust line and a downstream port connected to the containment through a backfeed line. The backfeed line contains a backfeed compressor. A re-cooling system for re-cooling the steam condenser is provided. The depressurization and cooling system is effective for re-cooling of the steam condenser. Accordingly, this is achieved as the re-cooling system is self-sustainable.

In order to provide a coolant tank for preventing a containment from being recompressed and reheated during the cooling of the containment upon occurrence of a design basis accident and a severe accident and a passive containment cooling system comprising the same, the present invention comprises: a storage tank for storing a coolant; a division part which is arranged within the storage tank and divides the inside of the storage tank into a first storage tank and a second storage tank to separate the coolant; a first heat exchanger which is extended from the storage tank to the containment and cools the containment on the basis of the coolant; and a unidirectional valve which is provided on the division part and allows the coolant of the second storage tank to be introduced into the first storage tank when the water level of the first storage tank is reduced.

In order to provide a coolant tank for preventing a containment from being recompressed and reheated during the cooling of the containment upon occurrence of a design basis accident and a severe accident and a passive containment cooling system comprising the same, the present invention comprises: a storage tank for storing a coolant; a division part which is arranged within the storage tank and divides the inside of the storage tank into a first storage tank and a second storage tank to separate the coolant; a first heat exchanger which is extended from the storage tank to the containment and cools the containment on the basis of the coolant; and a unidirectional valve which is provided on the division part and allows the coolant of the second storage tank to be introduced into the first storage tank when the water level of the first storage tank is reduced.

In conjunction with a pressurized water reactor (PWR) and a pressurizer configured to control pressure in the reactor pressure vessel, a decay heat removal system comprises a pressurized passive condenser, a turbine-driven pump connected to suction water from at least one water source into the reactor pressure vessel; and steam piping configured to deliver steam from the pressurizer to the turbine to operate the pump and to discharge the delivered steam into the pressurized passive condenser. The pump and turbine may be mounted on a common shaft via which the turbine drives the pump. The at least one water source may include a refueling water storage tank (RWST) and/or the pressurized passive condenser. A pressurizer power operated relief valve may control discharge of a portion of the delivered steam bypassing the turbine into the pressurized passive condenser to control pressure in the pressurizer.

In conjunction with a pressurized water reactor (PWR) and a pressurizer configured to control pressure in the reactor pressure vessel, a decay heat removal system comprises a pressurized passive condenser, a turbine-driven pump connected to suction water from at least one water source into the reactor pressure vessel; and steam piping configured to deliver steam from the pressurizer to the turbine to operate the pump and to discharge the delivered steam into the pressurized passive condenser. The pump and turbine may be mounted on a common shaft via which the turbine drives the pump. The at least one water source may include a refueling water storage tank (RWST) and/or the pressurized passive condenser. A pressurizer power operated relief valve may control discharge of a portion of the delivered steam bypassing the turbine into the pressurized passive condenser to control pressure in the pressurizer.

A component cooling water system for a nuclear power plant. In one embodiment, the system includes an inner containment vessel housing a nuclear reactor and an outer containment enclosure structure. An annular water reservoir is formed between the containment vessel and containment enclosure structure which provides a heat sink for dissipating thermal energy. A shell-less heat exchanger is provided having an exposed tube bundle immersed in water held within the annular water reservoir. Component cooling water from the plant flows through the tube bundle and is cooled by transferring heat to the annular water reservoir. In one non-limiting embodiment, the tube bundle may be U-shaped.

A component cooling water system for a nuclear power plant. In one embodiment, the system includes an inner containment vessel housing a nuclear reactor and an outer containment enclosure structure. An annular water reservoir is formed between the containment vessel and containment enclosure structure which provides a heat sink for dissipating thermal energy. A shell-less heat exchanger is provided having an exposed tube bundle immersed in water held within the annular water reservoir. Component cooling water from the plant flows through the tube bundle and is cooled by transferring heat to the annular water reservoir. In one non-limiting embodiment, the tube bundle may be U-shaped.

A safety injection device includes a containment building, a reactor coolant system provided inside the containment building and accommodating a reactor coolant formed to carry heat energy generated according to fission of fuel, a cooling water storage section accommodating cooling water injected into the reactor coolant system, a power producing section producing power with steam discharged from the reactor coolant system in case of an accident, a steam supply pipe transmitting steam discharged from the reactor coolant system to the power producing section, a steam discharge pipe discharging steam drove the power producing section and a safety injection line supplying cooling water accommodated in the cooling water storage section to the inside of the reactor coolant system. In addition, cooling water accommodated in the cooling water storage section is supplied to the inside of the reactor coolant system, based on the power produced by the power producing section, through a cooling water inlet pipe connecting the cooling water storage section and the power producing section, the cooling water discharge pipe connecting the power producing section and the safety injection line, and the safety injection line.