Patent Number: 
Section: claims

1. A passive residual heat removal system, comprising:a plate type heat exchanger configured to exchange heat between secondary system fluid and cooling fluid, wherein the secondary system fluid has received sensible heat in a reactor coolant system and residual heat in a core, and wherein the cooling fluid is introduced from an inside or outside of a containment;a circulation line configured to connect a steam generator to the plate type heat exchanger to form a circulation flow path of the secondary system fluid, wherein the steam generator is disposed at a boundary between a primary system and a secondary system;an emergency cooling water storage section formed to store the cooling fluid therewithin and installed at an outside of the containment; anda plurality of the plate type heat exchangers installed within the emergency cooling water storage section,wherein the plurality of the plate type heat exchangers are all connected to the circulation line to receive the secondary system fluid through the circulation line, andthe circulation line is first branched into a plurality of lines in a position facing a plate type heat exchanger located at the center of the plurality of the plate type heat exchangers and the branched lines are connected to the plurality of plate type heat exchangers, respectively,wherein a lower part of each of the plate type heat exchangers is immersed into the cooling fluid within the emergency cooling water storage section to allow the cooling fluid within the emergency cooling water storage section and atmosphere outside the containment to pass through a plurality of first channels which are provided within each of the plate type heat exchangers, and an upper part of each of the plate type heat exchangers is protruded to an upper portion of the emergency cooling water storage section through the emergency cooling water storage section to discharge the cooling fluid and fluid evaporated by heat transfer with the secondary system fluid in the atmosphere to an outside. 2. The passive residual heat removal system of claim 1, wherein each of the plate type heat exchangers comprise at least one of:a printed circuit type heat exchanger provided with channels formed by diffusion bonding and densely formed by a photochemical etching technique; anda plate type heat exchanger configured to extrude a plate to form channels, and formed to couple the plates using at least one of a gasket, a welding, and a brazing welding methods. 3. The passive residual heat removal system of claim 1,wherein each of the plate type heat exchangers comprise a plurality of channels for exchanging heat while maintaining a pressure boundary to the cooling fluid with the secondary system fluid supplied through the circulation line, andwherein the plurality of channels comprises:the plurality of first channels arranged to be separated from one another to allow the cooling fluid to pass therethrough; anda plurality of second channels formed to allow the secondary system fluid to pass therethrough, and alternately arranged with the first channels to exchange heat while maintaining a pressure boundary to the cooling fluid. 4. The passive residual heat removal system of claim 3, wherein the passive residual heat removal system further comprises:a first inlet header formed at an inlet of the plurality of first channels to distribute the cooling fluid to each first channel;a first outlet header formed at an outlet of the plurality of the first channels to collect the cooling fluid that has passed through each first channel;a second inlet header formed at an inlet of the plurality of second channels to distribute the secondary system fluid to each second channel; anda second outlet header formed at an outlet of the plurality of the second channels to collect the secondary system fluid that has passed through each second channel. 5. The passive residual heat removal system of claim 3, wherein the circulation line comprises:a steam line branched from a main steam line and connected to an inlet of each of the second channels to receive the secondary system fluid from the main steam line extended from an outlet of the steam generator; anda feedwater line branched from a main feedwater line extended to an inlet of the steam generator and connected to an outlet of each of the second channels to transfer heat to the cooling fluid and recirculate the cooled secondary system fluid to the steam generator. 6. The passive residual heat removal system of claim 5, wherein the plate type heat exchanger is installed in an inner space of the containment, and communicates with an outside of the containment by a connection line in which an inlet and an outlet of the first channel pass through the containment to allow atmosphere outside the containment to pass through the first channel. 7. The passive residual heat removal system of claim 5, wherein each of the plate type heat exchangers is installed outside of the containment, and the steam line and the feedwater line are connected to the main steam line and main feedwater line from an outside of the containment. 8. The passive residual heat removal system of claim 5, wherein the emergency cooling water storage section is provided with an opening portion at an upper portion thereof to dissipate heat transferred by evaporating the cooling fluid stored therewithin during a temperature increase due to heat transferred from the secondary system fluid to the cooling fluid. 9. The passive residual heat removal system of claim 8, wherein each of the plate type heat exchangers is installed in an inner space of the containment, and an inlet and outlet of each of the first channels are connected to the emergency cooling water storage section by a connection line passing through the containment to allow cooling fluid within the emergency cooling water storage section to pass through each of the first channels. 10. The passive residual heat removal system of claim 8, wherein at least part of each of the plate type heat exchangers is installed within the emergency cooling water storage section to allow at least part thereof to be immersed into the cooling fluid. 11. The passive residual heat removal system of claim 3, wherein the circulation line comprises:a steam line at least part of which is connected to the reactor coolant system and an inlet of the second channel to receive the primary system fluid from the reactor coolant system to transfer said fluid to each of the plate type heat exchangers; andan injection line at least part of which is connected to an outlet of each of the second channels and the reactor coolant system to reinject the primary system fluid cooled by transferring heat to the cooling fluid to the reactor coolant system. 12. The passive residual heat removal system of claim 1, wherein each of the plate type heat exchangers further comprise:a casing formed to surround at least part of each of the plate type heat exchangers; anda cooling fin formed to surround at least part of the casing to expand a heat transfer area.