JP2014071054A - Decay heat removal system of coolant housing container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reliability of a decay heat removal system and thus attain an improvement in safety of a fast breeder reactor type nuclear power generation system, even at the time of station blackout, by improving heat removal performance of an air cooler installed together in a cooling system applicable to a reactor and an intermediate heat exchanger that are a coolant housing container.SOLUTION: A decay heat removal system according to the present invention includes: a coolant housing container which houses a core coolant in the inside thereof, and in which an upward air flow passage is formed for guiding outside air introduced to the exterior thereof and heating it with a wall surface; a heat transfer-tube coil immersed in the core coolant inside the coolant housing container; an air cooler which forms a circulation path of the core coolant between the heat transfer-tube coil and itself and cools the core coolant by air; and a blower for supplying the air cooler with the air. In the upward air flow passage, an outlet thereof is opened to the atmosphere and also a portion thereof is connected to an air flow path of the blower.

Description

  The present invention relates to a decay heat removal system for a coolant container, and more particularly to a decay heat removal system for a coolant container that passively removes decay heat when a reactor is shut down in a fast breeder reactor nuclear power generation system.

  In the fast breeder reactor nuclear power generation system, as shown in FIG. 2, a primary cooling system CL1 that circulates, for example, sodium Na as a primary coolant between the reactor vessel RV and the intermediate heat exchanger IHX, and an intermediate heat exchange Work is performed using the secondary cooling system CL2 that circulates, for example, sodium Na as the secondary coolant between the generator IHX and the steam generator SG, and the steam S generated by the steam generator SG. An indirect power generation system consisting of three systems of a water / steam system CL3 that circulates steam instead of water is adopted.

  Specifically, the water / steam system CL3 sends the steam S to the main steam pipe to the turbine T (high pressure turbine and low pressure turbine), and generates power (work) by the generator G linked with the shaft of the turbine T. The steam used for work is returned to the water W by the condenser C installed on the low pressure turbine outlet side, and then heated and passed through a plurality of feed water heaters and feed water pumps (not shown), respectively. After the pressure is increased, water is supplied into the steam generator SG. This water / steam system CL3 is configured similarly to the boiling water type or pressurized water type light water reactor nuclear power generation system.

  By the way, a general fast breeder nuclear power generation system is provided with a decay heat removal system device for removing decay heat (residual heat) generated even after the core RC is stopped. As shown in FIG. 2, the decay heat removal system apparatus includes a reactor vessel cooling system DRACS (Direct Reactor Auxiliary Cooling System) in which a heat exchanger is directly immersed in a reactor vessel RV to cool the core. An intermediate heat exchanger cooling system PRACS (Primary Reactor Auxiliary Cooling System) for cooling by incorporating an auxiliary cooler into the cooling system CL1 and a cooling system provided with an auxiliary cooler in the secondary cooling system CL2 from the secondary cooling pipe There is a secondary cooling system branch cooling system IRACS (Intermediate Reactor Auxiliary Cooling System) that is often installed in a branched manner. Non-Patent Document 1 describes these decay heat removal system devices.

  In FIG. 2, AC provided in each cooling system is an air cooler. The air cooler AC cools sodium Na, which is a coolant, by heat exchange between sodium Na, which is a primary and secondary system coolant, taken out from each place of the primary cooling system CL1 or the secondary cooling system CL2, and air.

  Further, in FIG. 2, the primary cooling system CL1 and a part of the secondary cooling system are accommodated in the storage facility CV. Among the cooling systems, the reactor vessel cooling system DRACS and the intermediate heat exchanger cooling system PRACS are used for cooling the equipment in the storage facility CV. On the other hand, the secondary cooling system branch cooling system IRACS is installed outside the storage facility CV and used for cooling equipment outside the storage facility CV.

  Here, the equipment in the containment facility CV to which the reactor vessel cooling system DRACS and the intermediate heat exchanger cooling system PRACS are applied is specifically the reactor vessel RV or the intermediate heat exchanger IHX. The reactor vessel RV or the intermediate heat exchanger IHX stores sodium Na, which is a coolant, inside, and can be called a coolant storage vessel. Heat transfer tube coils 5D and 5P constituting part of the reactor vessel cooling system DRACS and the intermediate heat exchanger cooling system PRACS are installed in the coolant storage vessel so as to be immersed in sodium.

  Also, decay heat removal system pipes PD and PP are provided between the air coolers ACD and ACP of the reactor vessel cooling system DRACS and the intermediate heat exchanger cooling system PRACS and the heat transfer tube coils 5D and 5P. Sodium circulates in the decay heat removal system pipes PD and PP. The circulating sodium is cooled by the air coolers ACD and ACP, and functions to remove decay heat generated in the coolant container.

  As described above, all of these decay heat removal system devices disclosed in Non-Patent Document 1 are air-cooled to air-cool the introduced core coolant (primary system coolant and secondary system coolant). And a decay heat removal system pipe for guiding the coolant Na of the core RC heated by decay heat to the air cooler AC.

  Non-Patent Document 2 introduces the concept of a reactor vessel auxiliary cooling system RVACS (Reactor Vessel Auxiliary Cooling System) that cools the outer wall of the reactor vessel by natural convection in the atmosphere as a decay heat removal system for the reactor vessel. Yes. In FIG. 2, RVACS has an air passage AP formed between a reactor vessel RV and a guard vessel GV outside the reactor vessel RV, and introduces outside air Ai from one port and discharges outside air from the other port. Air flows by convection along the outer wall of the reactor vessel and cools the reactor vessel from the outside. Note that the other port is placed at a higher installation position than the one port by a chimney or the like, thereby increasing the cooling effect.

Masao Hori, Basic Fast Reactor Engineering Editorial Committee (edition), Basic Fast Reactor Engineering, Nikkan Kogyo Shimbun, October 1993, Figure 6.2 on page 106 Magazine "Toshiba Review" Vol. 65 No. 12 (2010) 50-54 “Small Fast Reactor 4S and Fast Reactor Technology” FIG.

  The present invention relates to a cooling system to which a reactor or an intermediate heat exchanger, which is a coolant storage container, is an application target among cooling systems constituting a decay heat removal system. That is, in the present invention, the reactor vessel cooling system DRACS and the intermediate heat exchanger cooling system PRACS are applied.

  In these decay heat removal systems, the heat transfer tubes led into the air cooler AC from the reactor vessel RV or the like have heat removal performance due to forced convection from the air blower provided when the reactor is shut down due to loss of external power or the like. Be improved. In other words, the decay heat removal function is achieved by a blower that uses another power source other than the external power source in the air cooler AC in order to remove decay heat in the reactor shutdown state such as loss of external power source. Here, the other power source other than the external power source is, for example, an emergency diesel generator, and the blower is driven by electricity from here.

  For this reason, in addition to the loss of external power, in addition to the loss of all power sources (SBO: Station Blackout), which is the state where another power source (emergency diesel generator) is also lost, the heat removal from the decay heat by the air cooler is natural. Performed in ventilation mode. Generally, in a fast breeder reactor nuclear power generation system, even when the air cooler is operated in the natural ventilation mode, the decay heat removal can be achieved passively by the combination with the natural circulation of sodium Na in the heat transfer tube. However, the heat removal performance is lower than when the blower is driven.

  On the other hand, the reactor vessel auxiliary cooling system RVACS that cools the outer wall of the reactor vessel by natural convection of the atmosphere is cooled by natural convection, so that its function is not lost even when the entire power supply is lost.

  The present invention improves the heat removal performance of an air cooler provided in a cooling system to which a reactor or an intermediate heat exchanger that is a coolant container is applied even when the entire power source is lost, and the decay heat removal system is improved. The purpose is to improve the reliability and improve the safety of the fast breeder reactor nuclear power generation system.

  In order to solve the above-mentioned problems, in the present invention, a coolant container is formed in which a core coolant is housed, and an ascending air flow passage is formed for guiding outside air introduced to the outside and heating it with a wall surface. A heat transfer tube coil immersed in the core coolant in the coolant container, an air cooler that forms a circulation path with the core coolant between the heat transfer tube coil and air cooling the core coolant, and air in the air cooler The ascending air flow passage is opened to the atmosphere at the outlet, and a part thereof is connected to the air flow path of the blower.

  In addition, the outlet of the rising air flow passage and the part of the air flow path of the blower are positioned higher than the height position of the introduction part for introducing outside air.

  The coolant container is a nuclear reactor vessel having a reactor core immersed in the core coolant therein.

  The coolant storage container is an intermediate heat exchanger that performs heat exchange between core coolants therein.

  The coolant was sodium, lead, or lead-bismuth.

  In the present invention, the passive safety and multiplicity of the decay heat removal system when the total power supply is lost can be realized, and the safety of the fast reactor power generation system can be improved.

The figure which shows the decay | disintegration heat removal system of the coolant storage container of this invention. The figure which shows the general decay heat removal system of the fast reactor shown by the nonpatent literature 1. FIG. FIG. 3 is a diagram illustrating the configuration of FIG. 2 in more detail with a piping configuration and device arrangement as a main component. The figure which shows the analysis result which showed specific numerical values, such as each part temperature immediately after a stop at the time of an accident from the rated driving | operation. The figure which showed the operation state of the reactor vessel cooling system DRACS and the reactor vessel auxiliary cooling system RVACS for each operation mode of the reactor.

  Embodiments of the present invention will be described below with reference to the drawings.

  Hereinafter, the decay heat removal system for a coolant storage container according to the present invention will be described. The overall configuration of the fast breeder reactor nuclear power generation system including the coolant storage container as the premise thereof is as illustrated in FIG. FIG. 3 is a more detailed description of the configuration of FIG.

  3 will be described in a very simple manner. The fast breeder nuclear power generation system includes a reactor vessel RV, a core RC containing a fissile material housed in the reactor vessel RV, and a primary cooling system from the reactor vessel RV. Intermediate heat exchanger IHX and primary main circulation pump 35 sequentially connected through pipe 33, and steam generator SG and secondary main circulation sequentially connected from intermediate heat exchanger IHX through secondary cooling system pipe 36 A main steam system pipe 31a that sends the steam generated by the pump 38 and the steam generator SG to the high-pressure turbine TH and the low-pressure turbine TL, and a condenser that condenses the steam after passing through the turbines TH and TL and returns it to water. C, a feed condensate piping 31b for returning the water condensed in the condenser C to the steam generator SG, a generator G connected to the shafts of the high pressure turbine TH and the low pressure turbine TL, and the downstream of the condenser C Supply and condensate piping on the side It is mainly composed of linked water supply pump 314 and the feed water heater 315. to 1b.

  In the fast breeder nuclear power generation system of this example, the primary coolant (sodium) heated in the core RC is passed through the intermediate heat exchanger IHX to heat the secondary coolant (sodium), and further the secondary A system coolant (sodium) is passed through the steam generator SG to generate steam in the main steam system pipe 31a, and this steam is guided to the high-pressure turbine TH and the low-pressure turbine TL, and the generator G generates power. The steam used for power generation is condensed into water by the condenser C, and then heated and pressurized through the feed water pump 314 and the feed water heater 315, respectively, and supplied to the steam generator SG.

  In this fast breeder reactor nuclear power generation system, two types of cooling systems are shown as decay heat removal system devices to be applied in the present invention. The first is a decay heat removal system heat exchanger (heat transfer tube coil) 5D installed in a reactor vessel RV which is a coolant storage vessel, an air cooler ACD, these heat transfer tube coils 5D and air cooling. It is the 1st decay heat removal system apparatus DRACS (reactor vessel cooling system) which consists of decay heat removal system piping PD which connects reactor ACD.

  The second is a decay heat removal system heat exchanger (heat transfer tube coil) 5P installed in an intermediate heat exchanger IHX which is a coolant storage container, an air cooler ACP, these heat transfer tube coils 5P and air. It is the 2nd decay heat removal system apparatus PRACS (intermediate heat exchanger cooling system) which consists of decay heat removal system piping PP which connects cooler ACP.

  According to this system configuration, when the reactor is shut down such as the loss of external power, the decay heat exchanged with the primary coolant (sodium) in the coolant storage container by the heat transfer tube coil 5D and the heat transfer tube coil 5P is It is supplied to air coolers ACD and ACP through decay heat removal system pipes PD and PP filled with decay heat removal system coolant (sodium), and is exchanged with the atmosphere by air coolers ACD and ACP. Heat is dissipated.

  In addition, the cooling system of the air coolers ACD and ACP can be a forced cooling system in which the air blower is driven to forcibly cool, or a natural cooling system in which the air blower is not driven. If the forced cooling method is used, the cooling efficiency of the decay heat removal system coolant can be increased, and if the natural cooling method is used, the equipment configuration can be simplified and the energy consumption can be reduced.

  In the present invention, as shown in FIG. 1, a reactor vessel auxiliary cooling system RVACS (Reactor Vessel) that cools the outer wall of a reactor vessel by natural convection in the atmosphere, as a cooling and removing system for a coolant container, in addition to DRACS and PRACS. A fast reactor type nuclear power generation system that is configured with two types (Auxiliary Cooling System) and has multiplicity as well as safety in the event of long-term loss of all power sources.

  In the following description with reference to FIG. 1, the configuration of the reactor vessel RV is shown here as the coolant storage vessel, but this may be an intermediate heat exchanger IHX. Each container contains sodium as a coolant, and the heat transfer tube coil 5 is immersed in sodium in order to remove this residual heat. In addition, an air passage by the reactor vessel auxiliary cooling system RVACS may be formed on the outer wall of the coolant storage vessel.

  Moreover, although the example which uses sodium as a coolant is demonstrated in this invention, this is good also as lead or lead-bismuth.

  In the decay heat removal system for a coolant container according to the present invention shown in FIG. 1, a reactor vessel cooling system DRACS and a reactor vessel auxiliary cooling system RVACS are skillfully combined. Therefore, in the following description, the reactor vessel cooling system DRACS will be described first, then the reactor vessel auxiliary cooling system RVACS will be described, and finally how to combine them will be described.

  First, the configuration of the reactor vessel cooling system DRACS will be described. In FIG. 1, the reactor vessel RV contains sodium Na as a coolant. The heat transfer tube coil 5 is immersed in the sodium Na. Sodium Na rises in the ascending pipe 6 by the natural circulation driving force of sodium Na, is cooled by the heat transfer pipe 9 in the air cooler ACD, and descends in the descending pipe 7.

  On the other hand, air for cooling sodium Na by the air cooler ACD is supplied from the blower BW. The air supplied from the blower BW is discharged via the inlet damper 10, the air cooler ACD, and the outlet damper 11 of the air cooler ACD. In the reactor vessel cooling system DRACS, the blower BW for forcibly cooling the heat transfer tube 9 of the air cooler ACD, the inlet damper 10 and the outlet damper 11 of the air cooler ACD receive power supply from the battery Bt. It is driven. Therefore, forced cooling using the blower BW cannot be performed when all power is lost. In the present invention, there is a device in the air flow path of the blower BW, but this will be performed after the description of the reactor vessel auxiliary cooling system RVAC.

  Next, the reactor vessel auxiliary cooling system RVACS will be described. In FIG. 1, a partition wall IW is disposed between a reactor vessel RV and a guard vessel GV outside the reactor vessel RV to form an ascending air passage APU and a descending air passage APD. Specifically, outside air is introduced from the outside air inlet Ai on the side surface of the reactor vessel RV, and air is guided to the bottom of the reactor vessel RV through the descending air passage APD. The partition wall IW is partitioned between the reactor vessel RV and the outer guard vessel GV so as to form a descending air passage APD on the outside and an ascending air passage APU on the inside. For this reason, the air that has passed through the outer descending air passage APD enters the inner ascending passage APU at the bottom, and is heated by the reactor vessel RV while rising, thereby generating natural convection. When the outside air is heated by the reactor vessel RV, the reactor vessel RV is cooled (residual heat removal). The ascending air passage APU is finally led to an external discharge port Ao such as a chimney and discharged to the outside. A damper 12 is provided in the ascending air passage APU, and the damper 12 is driven by receiving electric power from an external power source (not shown) or the battery Bt.

  Thus, the partition wall IW is installed so as to cover the surface of the reactor vessel RV, and the ascending channel APU that rises as the air is heated by the heat transmitted from the reactor vessel RV through heat conduction, and the ascending channel APU A duct 17 that is installed so as to cover the outside and is installed above the descending flow path APD in which the outside air taken in from the upper inflow port descends and above the ascending path APU, and discharges heated air to the outside. Form. The reactor vessel auxiliary cooling system RVACS (Reactor Vessel Auxiliary Cooling System) is generally configured as described above.

  In the present invention, a part of the air flow passage of the reactor vessel cooling system DRACS and the reactor vessel auxiliary cooling system RVACS which are originally configured independently as described above is shared. Specifically, the air flow path of the blower BW of the reactor vessel cooling system DRACS was connected to the rising air passage APU of the reactor vessel auxiliary cooling system RVACS. However, although not shown in FIG. 1, the air from the blower BW of the reactor vessel cooling system DRACS does not flow back into the ascending flow path APU of the reactor vessel auxiliary cooling system RVACS. A stop valve is installed.

  The overall operation when the above configuration is adopted will be described below. FIG. 5 is a diagram showing the operation states of the reactor vessel cooling system DRACS and the reactor vessel auxiliary cooling system RVACS for each operation mode of the reactor. In this figure, the vertical axis represents each operation mode of the nuclear reactor, during normal operation, when external power is lost, and when all power is lost. The horizontal axis shows the operating states of the blower BW and the dampers 10, 11, and 12 as the operating states of the reactor vessel cooling system DRACS and the reactor vessel auxiliary cooling system RVACS.

  In the following description, the dampers 10, 11, and 12 can be opened or closed by a control signal. However, when the drive power supply is lost, the dampers 10, 11, and 12 are opened by mechanical force such as spring force. Yes.

  First, the normal operation will be described. At this time, the damper 12 provided in the ascending air passage APU of the reactor vessel auxiliary cooling system RVACS is in a position (closed state) where the air flow in the ascending air passage APU is blocked by the control signal. Therefore, the reactor vessel auxiliary cooling system RVACS is not cooled.

  The blower BW on the reactor vessel cooling system DRACS side is driven by power supply only from, for example, the emergency battery Bt, and is therefore in a stopped state during normal operation. In addition, the inlet damper 10 and the outlet damper 11 of the air cooler ACD are placed at a position (closed state) where the air flow is blocked by a control signal. Therefore, the cooling in the reactor vessel cooling system DRACS is not performed.

  As described above, neither the reactor vessel auxiliary cooling system RVACS nor the reactor vessel cooling system DRACS is in a state of being able to remove the heat of the reactor during the normal operation, and thus generated in the reactor vessel RV during the normal operation. All the amount of heat is used for power generation purposes, preventing the amount of heat from being released unnecessarily.

  Next, the case when the external power source is lost will be described. At this time, the damper 12 provided in the ascending air passage APU of the reactor vessel auxiliary cooling system RVACS is in a position (closed state) where the air flow in the ascending air passage APU is blocked by the control signal. Therefore, the reactor vessel auxiliary cooling system RVACS is not cooled.

  On the other hand, the reactor vessel cooling system DRACS side is as follows. First, the dampers 10 and 11 of the reactor internal cooling system DRACS are automatically opened by the reactor trip signal when the reactor is shut down due to loss of the external power source, and the blower BW is similarly activated by the reactor trip signal. . The blower BW is driven by an AC power generated by an emergency diesel generator.

  Next, a total power loss SBO is assumed. At this time, all the dampers 10, 11, and 12 are in a state in which their drive power is lost and are in an open state. Accordingly, first, the descending path APD and the ascending path APU are formed by the reactor vessel auxiliary cooling system RVACS, thereby constituting a natural cooling system.

  At this time, since the blower BW is stopped due to loss of power on the reactor vessel cooling system DRACS side, the air cooler ACD is removed by natural heat dissipation of the heat transfer tube 9. That is, the air flow branched from the damper 12 in the ascending path APU of the reactor vessel auxiliary cooling system RVACS flows through the flow path formed by the dampers 10 and 11 in the released state, and the heat transfer tube 9 of the air cooler ACD is naturally passed through. Remove heat by heat dissipation.

  As described above, in the present invention, the reactor vessel auxiliary cooling system RVACS is passively driven by the decay heat generated in the core RC, and the upward flow of the air passes through the air flow path of the blower BW. It is also introduced into the heat transfer tube 9 in the cooler APD. As a result, the heat transfer coefficient on the surface of the heat transfer tube 9 is greatly increased as compared with that during natural heat dissipation, so decay heat is attenuated and the rising flow velocity in the rising flow path APU of the reactor vessel auxiliary cooling system RVACS is several m / The heat removal performance of the reactor vessel cooling system DRACS is maintained until the flow rate becomes lower than s.

  On the other hand, even when the total power loss SBO continues for a long time and the heat removal performance of the reactor vessel cooling system DRACS cannot be expected, the heat removal performance by the reactor vessel auxiliary cooling system RVACS is large in decay heat. It is automatically maintained depending on the size.

  In order to efficiently perform the cooling according to the present invention, the outlet of the rising air flow passage and the part of the air flow path of the blower should be higher than the height of the introduction part for introducing the outside air. .

  FIG. 4 is an analysis result showing specific numerical values such as the temperature of each part of the present invention immediately after stopping during an accident from the rated operation. In the figure, first, regarding the reactor core RC, which is the source of all heat, the core inlet coolant (Na) temperature TA is about 400 degrees, and the core outlet coolant (Na) temperature TB is about 550 degrees. .

  Accordingly, the coolant temperature (TC) TC at the inlet side of the heat transfer tube 9 of the air cooler ACD of the reactor internal cooling system DRACS is also about 550 degrees. However, TC is a few degrees lower than the core plenum coolant temperature depending on the situation.

  On the other hand, regarding the temperature condition on the reactor vessel auxiliary cooling system RVACS side, about 30 degrees of air is taken in as the outside air TD. The reactor vessel RV surface average temperature TE in contact with the outside air TD is about 130 degrees. As a result of the heat exchange here, the ascending air average flow velocity SP is about 6 m / s. Furthermore, the average air temperature in the ascending flow path APU, the air cooler 9 inlet air temperature (at the time of an accident), and the outlet air Ao temperature TE are all about 100 degrees.

  In response to the above results, the temperature of the air cooler ACD heat transfer tube 9 outlet coolant (Na) decreases to about 500 degrees.

  The above analysis is an example in which the effect of the present invention has been examined for a fast breeder reactor nuclear power generation system having an electric output of 500,000 kW and an average burnup of core fuel of 150 GWd / t. The diameter of the reactor vessel RV in FIG. 1 is about 10 m, the height is about 16 m, and the height above the reactor vessel RV of the duct of the reactor vessel auxiliary cooling system RVACS is about 16 m. The fuel of the core is a composition obtained by multiple recycling of the spent fuel of the fast breeder nuclear power generation system. The weight ratio of Pu to the total heavy metals in the core fuel is about 19%, and the weight ratio of the minor actinide MA is about 1%. .

  Furthermore, the decay heat after about one month after the reactor shutdown is about 0.2% of the reactor heat output during rated operation. In this case, the temperature of the air at the duct outlet of the reactor vessel auxiliary cooling system RVACS is about 100 ° C., and the flow velocity is about 6 m / s. The temperature of sodium Na in the air cooler ACD heat transfer tube 9 of the reactor internal cooling system DRACS is about 350 ° C., which is caused by the heat drop from the duct outlet air temperature and the outlet air flow velocity of about 6 m / s. Considering the effect of increasing the surface heat transfer coefficient (about 20 times), it can be seen that the decay heat removal is sufficiently possible.

  In the case of FIG. 5, the damper 12 is kept closed when the external power supply is lost. By opening the damper 12 in this state, cooling by the reactor vessel auxiliary cooling system RVACS is also used when the external power supply is lost. It is also possible.

  As described above in detail, according to the present invention, even when the entire power supply is lost, the heat removal performance of the air cooler provided in the cooling system to which the reactor or intermediate heat exchanger that is the coolant storage container is applied is provided. It is possible to improve the reliability of the decay heat removal system.

5D, 5P: Heat transfer tube coil, 6: Upward piping, 7: Downward piping, 10: Inlet damper, 11: Outlet damper, 33: Primary cooling system piping, 35: Primary main circulation pump, 36: Secondary cooling system piping, 38: Secondary main circulation pump, 31a: Main steam system pipe, 31b: Feed / condensate system pipe, 314: Feed water pump, 315: Feed water heater, RV: Reactor vessel, IHX: Intermediate heat exchanger, Na: Sodium, CL1: Primary cooling system CL1, SG: Steam generator, CL2: Secondary cooling system, S: Steam, CL3: Water / steam system, T: Turbine (high pressure turbine and low pressure turbine), G: Generator, C: Recovery Water vessel, W: Water, RC: Core, RV: Reactor vessel, DRACS: Reactor vessel cooling system, PRACS: Intermediate heat exchanger cooling system, IRACS: Secondary cooling system branch Rejection system, CV: containment facility, ACD, ACP: air cooler, PD, PP: decay heat removal system piping, RVACS: reactor vessel auxiliary cooling system, GV: guard vessel, BW: blower, Bt: battery, APU: Ascending air passage, APD: Falling air passage, IW: Bulkhead

Claims (8)

A coolant storage container that stores a core coolant therein, leads an outside air introduced to the outside, and forms a rising air flow passage for heating the wall surface, and a core coolant in the coolant storage container. An immersed heat transfer tube coil, an air cooler that forms a circulation path by the core coolant between the heat transfer tube coil and air-cools the core coolant, and a blower that supplies air to the air cooler,
The rising air flow passage has an outlet opened to the atmosphere, and a part of the rising air flow passage is connected to the air flow path of the blower. In the cooling heat removal system for the coolant container according to claim 1,
A cooling heat removal system for a coolant container, wherein an outlet of the rising air flow passage and a portion of an air flow path of the blower are higher than a height position of an introduction portion for introducing outside air. . In the cooling heat removal system for the coolant storage container according to claim 1 or 2,
The coolant storage container decay heat removal system according to claim 1, wherein the coolant storage container is a reactor container having a reactor core immersed in a core coolant therein. In the cooling heat removal system for the coolant storage container according to claim 1 or 2,
The cooling material storage container is an intermediate heat exchanger for exchanging heat between core coolants therein, wherein the cooling material container has a decay heat removal system. In the cooling heat removal system of the coolant storage container according to any one of claims 1 to 4,
A cooling heat removal system for a coolant container, wherein the coolant is sodium, lead, or lead-bismuth. In the cooling heat removal system of the coolant storage container according to any one of claims 1 to 5,
A decay heat removal system for a coolant container, wherein a part of the outside air passing through the rising air flow passage is led to an air flow path of the blower and given to the air cooler in the event of a loss of all power sources. In the decay heat removal system for a coolant storage container according to any one of claims 1 to 6,
During normal operation, the air cooler is in a state where neither the air from the blower nor part of the outside air branched from the rising air flow passage is allowed to flow. Decay heat removal system. The decay heat removal system for a coolant storage container according to any one of claims 1 to 7,
A system for removing decay heat of a coolant container, wherein at least air from the blower is passed through the air cooler when an external power supply loss accident occurs.

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