Reactor containment vessel cooling system, reactor containment vessel, and reactor containment vessel cooling method

Abstract

A reactor containment vessel cooling technology for preventing the cooling capability and structural integrity of a reactor containment vessel cooling system from decreasing by lowering the temperature of water vapor and gases acquired by the reactor containment vessel cooling system is provided. Based on the technology, the present invention provides a reactor containment vessel cooling system that acquires water vapor in a reactor containment vessel by using water vapor pressure in the vessel as a drive force, condenses the acquired water vapor into condensate, and cools the reactor containment vessel with the condensate. The reactor containment vessel cooling system includes a heat exchange pool 21 that is arranged apart from a dry well 15 and a suppression chamber 16 in the reactor containment vessel 10 and stores a medium for cooling water vapor, a heat exchanger 22 that is immersed in the heat exchange pool 21 , acquires water vapor from the dry well 15 in the reactor containment vessel 10 , and performs heat exchange between the eater vapor and the cooling medium in the heat exchange pool 21 to generate condensate, and a condensate drain pipe 25 that extracts the condensate from the heat exchanger 22 and guides and discharges the condensate toward a reactor pressure vessel 12.

1 . A reactor containment vessel cooling system for cooling a reactor containment vessel by acquiring the water vapor in the reactor containment vessel and by using water vapor pressure in the vessel as a drive force to thereby condense the acquired water vapor into condensate and cool the reactor containment vessel with the condensate, the cooling system comprising;
 a heat exchange pool that is arranged apart from a dry well and a suppression chamber in the reactor containment vessel and stores a medium for cooling acquired water vapor;   a heat exchanger that is immersed in the heat exchange pool, acquires water vapor from the dry well in the reactor containment vessel, and performs heat exchange between the water vapor and the cooling medium in the heat exchange pool so as to convert the water vapor into condensate; and   a condensate drain pipe that extracts the condensate from the heat exchanger and guides and discharges the condensate toward a reactor pressure vessel.   
     
     
         2 . The reactor containment vessel cooling system according to  claim 1 , wherein the condensate drain pipe is configured to discharge the condensate in a way that the condensate flows down along a side surface of a thermally insulating member that surrounds the reactor pressure vessel. 
     
     
         3 . The reactor containment vessel cooling system according to  claim 2 , wherein the condensate drain pipe id configured to discharge the condensate from a position above a reactor shielding wall provided outside the thermally insulating member at a side surface of the thermally insulating member. 
     
     
         4 . The reactor containment vessel cooling system according to  claim 3 , wherein the condensate drain pipe includes a ring-shaped header tube which circumferentially surrounds the thermally insulating member and through which the condensate flows and a plurality of condensate discharge ports provided at intervals along the header tube in a circumferential direction thereof. 
     
     
         5 . The reactor containment vessel cooling system according to  claim 1 , wherein the condensate drain pipe id configured to discharge the condensate in a way that the condensate flows down along a side surface of the reactor pressure vessel. 
     
     
         6 . The reactor containment vessel cooling system according to  claim 5 , wherein the condensate drain pipe is configured to discharge the condensate from a position above a reactor shielding wall at a side surface of the reactor pressure vessel. 
     
     
         7 . The reactor containment vessel cooling system according to  claim 6 , wherein the condensate drain pipe includes a ring-shaped header tube which circumferentially surrounds the reactor pressure vessel and through which the condensate flows and a plurality of discharge ports which are provided at intervals along the header tube in a circumferential direction thereof and through which the condensate is discharged. 
     
     
         8 . The reactor containment vessel cooling system according to  claim 7 , wherein each of the discharge ports is formed of a nozzle penetrating a thermally insulating member that surrounds the reactor pressure vessel from outside to inside. 
     
     
         9 . The reactor containment vessel cooling system according to  claim 7 , wherein the header tube is embedded in the thermally insulating member. 
     
     
         10 . The reactor containment vessel cooling system according to  claim 1 , wherein a part of the condensate drain pipe is replaced with curved tube having a downwardly convex shape. 
     
     
         11 . A reactor containment vessel comprising:
 a reactor pressure vessel that accommodates a core;   a reactor shielding wall provided to surround an outer circumferential surface of the reactor pressure vessel;   a dry well that forms a space that accommodates the reactor pressure vessel;   a suppression chamber for controlling an internal pressure in the reactor containment vessel; and   a reactor containment vessel cooling system that acquires water vapor in the reactor containment vessel by using water vapor pressure in the vessel as a drive force to thereby condense the acquired water vapor into condensate and cool the reactor containment vessel with the condensate,   wherein the reactor containment vessel cooling system includes: a heat exchange pool that is arranged apart from the dry well and the suppression chamber in the reactor containment vessel and stores a medium for cooling acquired water vapor; a heat exchanger that is immersed in the heat exchange pool, acquires water vapor from the dry well in the reactor containment vessel, and performs heat exchange between the water vapor and the cooling medium in the heat exchange pool so as to convert the water vapor into condensate; and a condensate drain pipe that extracts the condensate from the heat exchanger and guides and discharges the condensate at the reactor pressure vessel.   
     
     
         12 . A reactor containment vessel cooling method for cooling an interior of the reactor containment vessel by acquiring water vapor in a reactor containment vessel and by using water vapor pressure in the vessel to thereby condense the acquired water vapor into condensate and cool an internal space of the reactor containment vessel with the condensate, the cooling method comprising:
 storing a water vapor cooling medium in a position set apart from a dry well and a suppression chamber in the reactor containment vessel; and   acquiring water vapor from the dry well in the reactor containment vessel, performing heat exchange between the water vapor and the cooling medium so as to convert the water vapor into condensate, and guiding and discharging the condensate at a reactor pressure vessel.