Molten corium cooling device and nuclear facility

Abstract

To cool a molten corium flowing out of a reactor vessel at an early stage.SOLUTION: A molten corium cooling device, in which a structure installed on a foundation portion of a reactor containment vessel supports a reactor and which cools a molten corium falling from a lower portion of a reactor vessel, includes: a water storage tank provided below the reactor vessel and storing cooling water; a molten corium receiving member which is disposed inside the water storage tank and on whose side portion a cooling water inflow portion is provided; and a support member that supports the molten corium receiving member so as to be movable to an upper position and a lower position according to the presence or absence of the molten corium.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a core melt cooling device and a nuclear power facility.

Background Art

[0002] A reactor containment vessel is erected on a solid ground such as rock, and a reactor is disposed inside. The reactor is supported by a concrete structure provided at the base of the reactor containment vessel. In nuclear power facilities, as a severe accident, an accident in which the core melt flows out of the reactor vessel is assumed. Since the core melt melts the lower part of the reactor vessel and drops downward, a cavity is provided below the reactor vessel, the core melt is received by the cavity, and the core melt is cooled by cooling water. As such a nuclear power facility, for example, there is one described in Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In conventional nuclear power facilities, when an accident occurs in which the core melt flows out of the reactor vessel, by operating a pump, cooling water is supplied to the core melt that has dropped into the cavity for cooling. However, when the power supply in the nuclear power facility is lost, the pump cannot be operated, and there is a risk that the core melt cannot be cooled early. Further, the cooling device described in Patent Document 1 cools the core melt by non-direct contact, and it is difficult to cool the core melt early.

[0005] The present disclosure addresses the above-described problems and aims to provide a core melt cooling device and a nuclear power facility that enable early cooling of the core melt flowing out of the reactor vessel.

Means for Solving the Problems

[0006] The core melt cooling device of the present disclosure for achieving the above object is a core melt cooling device that cools the core melt falling from the lower part of the reactor vessel, wherein the reactor is supported by a structure installed at the base of the reactor containment vessel. The core melt cooling device includes a water storage tank provided below the reactor vessel for storing cooling water, a core melt receiving member disposed inside the water storage tank and having a cooling water inflow portion provided on a side portion thereof, and a support member that supports the core melt receiving member and is movably supported between a raised position and a lowered position according to the presence or absence of the core melt.

[0007] The nuclear power facility of the present disclosure includes a reactor disposed inside the reactor containment vessel and the core melt cooling device.

Advantages of the Invention

[0008] According to the core melt cooling device and the nuclear power facility of the present disclosure, the core melt flowing out of the reactor vessel can be cooled early.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0010] Hereinafter, with reference to the drawings, preferred embodiments of the present disclosure will be described in detail. Note that the present disclosure is not limited by this embodiment, and when there are multiple embodiments, those configured by combining each embodiment are also included. In addition, the constituent elements in the embodiment include those that can be easily assumed by those skilled in the art, substantially the same ones, and those within the so-called equivalent range.

[0011] [First Embodiment] <Nuclear Facility> FIG. 1 is a schematic diagram showing a nuclear facility according to the first embodiment.

[0012] As shown in FIG. 1, the nuclear facility 10 is applied to a nuclear power plant. The nuclear facility 10 of the present embodiment uses light water as a reactor coolant and a neutron moderator, forms high-temperature and high-pressure water that does not boil throughout the primary system, sends the high-temperature and high-pressure water to a steam generator to generate steam by heat exchange, and sends the steam to a turbine generator to generate electricity, and includes a pressurized water reactor (PWR). However, the reactor is not limited to a pressurized water reactor and can also be applied to other reactors such as a boiling water reactor (BWR).

[0013] The reactor containment vessel 11 is arranged on a solid ground G such as rock. The reactor containment vessel 11 includes a base portion 12 and a containment vessel main body 13. The base portion 12 is installed on the ground G, and the containment vessel main body 13 is erected on the base portion 12. The base portion 12 and the containment vessel main body 13 form an integral structure. The containment vessel main body 13 is provided with a structure 14 constructed by reinforced concrete or the like inside. The structure 14 is arranged inside the containment vessel main body 13 above the base portion 12.

[0014] The reactor containment vessel 11 has a reactor 15 disposed at its central part. The structure 14 defines a cylindrical space portion 16 at the central part of the reactor containment vessel 11. The reactor 15 is disposed in the space portion 16 and is suspended and supported by the structure 14 forming the inner wall portion of the space portion 16. A plurality of steam generators 17 are disposed around the reactor 15 in the reactor containment vessel 11. The plurality of steam generators 17 are supported by the structure 14. The reactor 15 and the plurality of steam generators 17 are connected by a cooling water pipe 18.

[0015] A cavity 19 is defined and formed below the reactor 15 in the reactor containment vessel 11. The cavity 19 receives and cools the core melt that falls from the reactor 15. The reactor containment vessel 11 is provided with a cooling water pit 20 for storing cooling water at the base portion 12, and a cooling water injection device 21 is provided at the upper part of the containment vessel main body 13. The cooling water pit 20 is connected to the cooling water injection device 21 by a cooling water path 22, and a cooling water pump 23 is provided in the cooling water path 22.

[0016] The reactor 15 is configured with a core 25 disposed inside a reactor vessel 24. The reactor vessel 24 is configured with a reactor vessel lid detachably provided at the upper part of the reactor vessel main body. The reactor vessel 24 is provided with an inlet nozzle for supplying light water (coolant) as primary cooling water and an outlet nozzle for discharging the light water at its upper side portion. The reactor vessel 24 has the cooling water pipes 18 from the steam generators 17 connected to the inlet nozzle and the outlet nozzle respectively. The core 25 disposed inside the reactor vessel 24 is composed of a plurality of fuel assemblies. The fuel assembly is composed of a large number of fuel rods bundled in a lattice shape by a support lattice. Note that a plurality of control rods for controlling the output of the reactor 15 are disposed together with the large number of fuel rods in the core 25.

[0017] The nuclear reactor 15 releases neutrons by nuclear fission of the nuclear fuel that constitutes the reactor core 25. Light water as a moderator and primary coolant reduces the kinetic energy of the released fast neutrons to thermal neutrons, making new nuclear fissions more likely to occur, and at the same time takes away the generated heat for cooling. At this time, by inserting control rods into the reactor core 25 and adjusting the number of neutrons generated in the reactor core 25, the output of the nuclear reactor 15 is adjusted.

[0018] The steam generator 17 is connected to a steam turbine provided outside the reactor containment vessel 11 via a steam pipe. The steam turbine is connected to a generator. The steam generator 17 generates steam by performing heat exchange between the high-temperature primary coolant supplied from the nuclear reactor 15 and the secondary coolant. The generated steam is sent to the steam turbine to drive it, and power generation is performed by the generator. The steam that has driven the steam turbine is returned to the steam generator 17 after being cooled.

[0019] <Core Melt Cooling Device> FIG. 2 is a schematic diagram showing the core melt cooling device of the second embodiment, and FIG. 3 is a schematic diagram showing the operation of the core melt cooling device.

[0020] As shown in FIGS. 1 and 2, the nuclear power facility 10 includes a core melt cooling device 30. The core melt cooling device 30 cools the core melt that falls from the lower part of the reactor vessel 24 constituting the nuclear reactor 15, with the nuclear reactor 15 supported by a structure 14 installed on the base portion 12 of the reactor containment vessel 11. The core melt cooling device 30 includes a cavity (water storage tank) 19, a core melt receiving member 31, and a support member 32.

[0021] The cavity 19 is provided in a concave shape with an upward opening in the base portion 12 located below the nuclear reactor 15, and is arranged at a position facing the lower part of the central portion of the nuclear reactor 15. The cavity 19 stores a predetermined amount of cooling water inside.

[0022] The core melt receiving member 31 is disposed inside the cavity 19. The outer dimensions of the core melt receiving member 31 are smaller than the inner dimensions of the cavity 19. That is, when the core melt receiving member 31 is disposed inside the cavity 19, a gap is secured between the outer surface of the core melt receiving member 31 and the inner surface of the cavity 19. The core melt receiving member 31 has a dish shape capable of receiving the core melt. In the present embodiment, the core melt receiving member 31 has a square box shape with an open top, but the shape is not limited. The core melt receiving member 31 only needs to have an open top, and for example, it may have a rectangular box shape, a flask shape with a lower part spreading outward in the horizontal direction, a hull shape that is long in the horizontal direction, or the like.

[0023] The core melt receiving member 31 has four side portions 31a and a bottom portion 31b. The side portions 31a are arranged along the vertical direction, the bottom portion 31b is arranged along the horizontal direction, and is integrally provided at the lower part of each side portion 31a. In this case, the upper surface of the bottom portion 31b is preferably flat, but it does not have to be flat. A plurality of cooling water inflow holes (cooling water inflow portions) 41 are provided in each side portion 31a of the core melt receiving member 31. The plurality of cooling water inflow holes 41 are provided at the upper part of each side portion 31a of the core melt receiving member 31. The cooling water inflow hole 41 is a circular through hole penetrating the outer surface and the inner surface of the side portion 31a of the core melt receiving member 31.

[0024] In the present embodiment, a plurality of cooling water inflow holes 41 are provided in a single row at intervals in the horizontal direction at the upper part of each side portion 31a of the core melt receiving member 31, but two or more rows may be provided. Further, the inner diameter dimension, shape, number, etc. of the cooling water inflow holes 41 are not limited either. Furthermore, the cooling water inflow hole 41 provided in the side portion 31a of the core melt receiving member 31 may be a cooling water inflow notch (cooling water inflow portion) 42. In this case, the cooling water inflow notch 42 is provided at the upper end portion of each side portion 31a of the core melt receiving member 31.

[0025] The support member 32 supports the core melt receiving member 31 inside the cavity 19. The support member 32 supports the core melt receiving member 31 so as to be movable between a raised position and a lowered position according to the presence or absence of the core melt. In the present embodiment, the support member 32 is a crushable beam disposed below the core melt receiving member 31. The crushable beam as the support member 32 is deformable when the core melt receiving member 31 receives the core melt 25A. The crushable beams as the support member 32 are arranged along the vertical direction and a plurality of them are arranged at intervals in the horizontal direction. The upper end of the crushable beam as the support member 32 is connected to the lower surface of the bottom 31b of the core melt receiving member 31, and the lower end is connected to the bottom surface inside the cavity 19.

[0026] When the core melt receiving member 31 is not receiving the core melt, the support member 32 supports the core melt receiving member 31 at a raised position (FIG. 2) where cooling water does not flow in from the cooling water inlet hole 41. Further, when the core melt receiving member 31 receives the core melt, the support member 32 supports the core melt receiving member 31 at a lowered position (FIG. 3) where cooling water flows in from the cooling water inlet hole 41.

[0027] That is, as shown in FIG. 2, when the core melt receiving member 31 is not receiving the core melt and no weight (load) is acting, the support member 32 supports the core melt receiving member 31 at the raised position. When the core melt receiving member 31 is supported at the raised position by the support member 32, the cooling water inlet hole 41 is located above the water surface of the cooling water stored in the cavity 19. Therefore, the cooling water in the cavity 19 does not flow into the inside from the cooling water inlet hole 41.

[0028] On the one hand, as shown in FIG. 3, when the core melt receiving member 31 receives the core melt 25A, the support member 32 deforms (breaks) due to the action of weight (load), causing the core melt receiving member 31 to descend. When the support member 32 deforms and supports the core melt receiving member 31 at the lowered position, the cooling water inlet hole 41 is located below the water surface of the cooling water stored in the cavity 19. Therefore, the cooling water in the cavity 19 flows into the core melt receiving member 31 from the cooling water inlet hole 41.

[0029] In this embodiment, the support member 32 is a crushable beam that can be deformed by the weight (load) of the core melt 25A received by the core melt receiving member 31, but the present invention is not limited to this configuration. For example, the support member 32 may be a crushable beam that can be deformed by the heat of the core melt received by the core melt receiving member 31. Alternatively, the support member 32 may be configured to suspend and support the core melt receiving member 31 with respect to the cavity 19, and may be a crushable beam that can be deformed (broken) by the weight (load) of the core melt 25A received by the support member 32.

[0030] <Method for Cooling Core Melt> As shown in FIG. 1, in the nuclear facility 10, for example, it is assumed that a severe accident occurs and a core damage accident due to core melting occurs. At this time, as shown in FIGS. 1 and 2, the lower part of the reactor vessel 24 is damaged in the reactor 15, and the core melt 25A in which the core 25 has melted flows out. The core melt 25A flowing out from the lower part of the reactor vessel 24 falls into the inside of the core melt receiving member 31 provided below the reactor vessel 24.

[0031] Before the core melt 25A flowing out from the lower part of the reactor vessel 24 falls into the inside of the core melt receiving member 31, since the core melt receiving member 31 does not receive the core melt 25A and no weight (load) is acting, the support member 32 supports the core melt receiving member 31 at the raised position without deforming. At this time, since the cooling water inlet hole 41 of the core melt receiving member 31 is located above the water surface of the cooling water stored in the cavity 19, cooling water does not flow in from the cooling water inlet hole 41.

[0032] As shown in FIG. 3, when the core melt 25A flowing out from the lower part of the reactor vessel 24 falls inside the core melt receiving member 31, the core melt receiving member 31 receives the core melt 25A, and the support member 32 deforms (breaks) under the action of the weight (load), and the core melt receiving member 31 descends. Then, the core melt receiving member 31 moves to the descending position, and since the cooling water inflow holes 41 are located below the water surface of the cooling water stored in the cavity 19, the cooling water flows in from the cooling water inflow holes 41.

[0033] The core melt 25A that has fallen inside the core melt receiving member 31 is cooled by the cooling water flowing in from each of the cooling water inflow holes 41. That is, the core melt 25A of the core melt receiving member 31 comes into contact with the cooling water flowing in from each of the cooling water inflow holes 41, and the cooling water is stored inside the core melt receiving member 31, so that it is slowly cooled. Therefore, a steam explosion is less likely to occur.

[0034] [Second Embodiment] FIG. 4 is a schematic diagram showing the nuclear power facility of the second embodiment. The basic configuration of the second embodiment is the same as that of the first embodiment described above. The members having the same functions as those of the first embodiment described with reference to FIG. 1 are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0035] As shown in FIGS. 1 and 4, the nuclear power facility 10 includes a core melt cooling device 30A. The core melt cooling device 30A includes a cavity 19, a core melt receiving member 31A, and a support member 33.

[0036] The core melt receiving member 31A is disposed inside the cavity 19. The core melt receiving member 31A is provided with a plurality of cooling water inflow holes (cooling water inflow portions) 41 and 43 in each side portion 31a. The plurality of cooling water inflow holes 41 and 43 are provided at the upper part of each side portion 31a of the core melt receiving member 31A. The cooling water inflow holes 41 and 43 are circular through holes penetrating the outer surface and the inner surface of the side portion 31a of the core melt receiving member 31A.

[0037] A plurality of coolant inlet holes 41 are provided at upper portions of respective side portions 31a of the core melt receiving member 31 with a horizontal interval therebetween. A plurality of coolant inlet holes 43 are provided at upper portions of respective side portions 31a of the core melt receiving member 31, below the coolant inlet holes 41, with a horizontal interval therebetween. The inner diameter of the coolant inlet holes 43 is larger than that of the coolant inlet holes 43.

[0038] Further, the core melt receiving member 31A is supported by a guide mechanism 51 so as to be movable along the vertical direction with respect to the cavity 19. The guide mechanism 51 is, for example, a guide rail provided on a vertical wall portion of the inner surface of the cavity 19. The guide rails are provided along the vertical direction on the vertical wall portion of the cavity 19 and a plurality of guide rails are provided with a horizontal interval therebetween. The outer surfaces of the respective side portions 31a of the core melt receiving member 31A are supported by the plurality of guide rails constituting the guide mechanism 51 so as to be movable along the vertical direction with respect to the cavity 19.

[0039] Furthermore, a sacrificial material concrete (sacrificial material) 52 is provided on the upper surface of the bottom portion 31b of the core melt receiving member 31A. The sacrificial material concrete 52 is a sacrificial material that lowers the melting point of the core melt 25A and reduces its viscosity, and is not limited to concrete.

[0040] The support member 33 supports the core melt receiving member 31A inside the cavity 19. The support member 33 supports the core melt receiving member 31A so as to be movable between a raised position and a lowered position according to the presence or absence of the core melt. In the present embodiment, the support member 33 is a crushable beam disposed below the core melt receiving member 31. The crushable beam as the support member 33 is deformable when the core melt receiving member 31A receives the core melt. The crushable beam as the support member 33 is fixed to the guide rails constituting the guide mechanism 51.

[0041] The support member 33 supports the core melt receiving member 31A at an elevated position where cooling water does not flow in from the cooling water inlet holes 41 and 43 when the core melt receiving member 31A is not receiving the core melt. Further, the support member 33 supports the core melt receiving member 31A at a lowered position where cooling water flows in from the cooling water inlet holes 41 and 43 when the core melt receiving member 31A receives the core melt.

[0042] That is, the support member 33 supports the core melt receiving member 31A at the elevated position when the core melt receiving member 31A is not receiving the core melt and no weight (load) is acting. When the core melt receiving member 31A is supported at the elevated position by the support member 33, the cooling water inlet holes 41 and 43 are located above the water surface of the cooling water stored in the cavity 19. Therefore, the cooling water in the cavity 19 does not flow into the inside through the cooling water inlet holes 41 and 43 for the core melt receiving member 31A.

[0043] On the other hand, when the core melt receiving member 31A receives the core melt, the support member 33 deforms (breaks) due to the action of the weight (load), causing the core melt receiving member 31A to descend. When the core melt receiving member 31A is supported at the lowered position as the support member 33 deforms, the cooling water inlet holes 41 and 43 are located below the water surface of the cooling water stored in the cavity 19. Therefore, the cooling water in the cavity 19 flows into the inside through the cooling water inlet holes 41 and 43 for the core melt receiving member 31A.

[0044] In addition, the core melt cooling device 30A is provided with a cooling water replenishing mechanism 53 for replenishing the cavity 19 with cooling water. That is, a replenishing tank 54 is arranged vertically above the cavity 19, the cavity 19 and the replenishing tank 54 are connected by a replenishing path 55, and an on-off valve 56 is provided in the replenishing path 55. In this case, the on-off valve 56 is preferably a manual type. The cooling water replenishing mechanism 53 can replenish the cooling water in the cavity 19 from the replenishing path 55 by free fall of the cooling water in the replenishing tank 54 by opening the on-off valve 56. Note that the cooling water replenishing mechanism 53 is not limited to this configuration. For example, when power is available or power is restored, the cooling water replenishing mechanism 53 may have an electric on-off valve 57 and an electric pump 58 so that it can be remotely operated, or both may be provided side by side.

[0045] When the lower part of the reactor vessel 24 of the nuclear reactor 15 is damaged, the core melt 25A in which the core 25 has melted flows out. The core melt 25A flowing out from the lower part of the reactor vessel 24 falls inside a core melt receiving member 31A provided below the reactor vessel 24.

[0046] When the core melt 25A flowing out from the lower part of the reactor vessel 24 falls inside the core melt receiving member 31A, the core melt receiving member 31A receives the core melt 25A, and the support member 33 is deformed (broken) by the action of the weight (load), and the core melt receiving member 31A descends. Then, the core melt receiving member 31A moves to the lowered position, and since the cooling water inflow holes 41, 43 are located below the water surface of the cooling water stored in the cavity 19, the cooling water flows in from the cooling water inflow holes 41, 43.

[0047] The core melt 25A that has fallen inside the core melt receiving member 31 is cooled by the cooling water flowing in from each of the cooling water inflow holes 41, 43. That is, the core melt 25A of the core melt receiving member 31A comes into contact with the cooling water flowing in from each of the cooling water inflow holes 41, 43, and the cooling water is stored inside the core melt receiving member 31A, so that it is slowly cooled. Therefore, a steam explosion is less likely to occur.

[0048] In addition, since the sacrificial material concrete 52 is provided inside the reactor core melt receiving member 31, the reactor core melt 25A that has fallen onto the reactor core melt receiving member 31 comes into contact with the sacrificial material concrete 52 and melts and mixes, thereby lowering the melting point and reducing the viscosity.

[0049] Moreover, since the reactor core melt 25A is at several thousand degrees Celsius, the cooling water that has cooled the reactor core melt 25A in the reactor core melt receiving member 31 vaporizes, reducing the cooling water in the cavity 19. At this time, an operator or a detector detects the reduction of the cooling water in the cavity 19 and activates the cooling water replenishing mechanism 53 to replenish the cooling water into the cavity 19.

[0050] [Operation and Effect of the Present Embodiment] In the reactor core melt cooling device according to the first aspect, in the reactor core melt cooling device 30 that supports the nuclear reactor 15 by the structure 14 installed in the base portion 12 of the nuclear reactor containment vessel 11 and cools the reactor core melt 25A that falls from the lower part of the reactor vessel 24, a cavity (water storage tank) 19 provided below the reactor vessel 24 for storing cooling water, reactor core melt receiving members 31, 31A disposed inside the cavity 19 and having cooling water inflow holes 41, 43 or a cooling water inflow notch 42 as cooling water inflow portions provided in side portions 31a, and support members 32, 33 that support the reactor core melt receiving members 31, 31A and are movably supported between a raised position and a lowered position according to the presence or absence of the reactor core melt 25A are provided.

[0051] According to the reactor core melt cooling device according to the first aspect, when the lower part of the reactor vessel 24 is damaged and the reactor core melt 25A in which the reactor core 25 has melted falls, the reactor core melt 25A falls onto the reactor core melt receiving members 31, 31A disposed inside the cavity 19. When the reactor core melt 25A falls onto the reactor core melt receiving members 31, 31A, the support members 32, 33 are deformed and the reactor core melt receiving members 31, 31A are lowered. Then, cooling water flows into the reactor core melt receiving members 31, 31A from the cooling water inflow holes 41, 43 or the cooling water inflow notch 42, and the reactor core melt 25A is cooled. As a result, even when the power supply in the nuclear power facility 10 is lost, the reactor core melt 25A flowing out from the reactor vessel 24 can be cooled early.

[0052] Further, according to the core melt cooling device, cooling water flows in from the cooling water inlet holes 41, 43 or the cooling water inlet notch 42 to cool the core melt 25A that has fallen onto the core melt receiving members 31, 31A, thereby suppressing the occurrence of a steam explosion due to the contact between the core melt 25A and a large amount of cooling water. Furthermore, the cavity 19 only supports the core melt receiving members 31, 31A by the support members 32, 33, suppressing the complication of the structure and suppressing an increase in the manufacturing cost.

[0053] The core melt cooling device according to the second aspect is the core melt cooling device according to the first aspect, and further, when the core melt receiving members 31, 31A are not receiving the core melt 25A, the support members 32, 33 support the core melt receiving members 31, 31A at an elevated position where cooling water does not flow in from the cooling water inlet holes 41, 43 or the cooling water inlet notch 42, and when the core melt receiving members 31, 31A receive the core melt 25A, the support members 32, 33 support the core melt receiving members 31, 31A at a lowered position where cooling water flows in from the cooling water inlet holes 41, 43 or the cooling water inlet notch 42. Thereby, by moving the core melt receiving members 31, 31A between the elevated position and the lowered position, the inflow and stop of the cooling water can be easily switched.

[0054] The core melt cooling device according to the third aspect is the core melt cooling device according to the second aspect, and further, the support members 32, 33 are disposed below the core melt receiving members 31, 31A and have crushable beams that deform when the core melt receiving members 31, 31A receive the core melt 25A. Thereby, the simplification of the structure can be achieved.

[0055] The core melt cooling device according to the fourth aspect is the core melt cooling device according to any one of the first to third aspects, and further, a guide mechanism 51 is provided for supporting the core melt receiving members 31, 31A so as to be movable along the vertical direction with respect to the cavity 19. Thereby, it is possible to suppress the inclination and overturning of the core melt receiving members 31, 31A with respect to the cavity 19, and the core melt 25A can be appropriately held by the core melt receiving members 31, 31A.

[0056] The core melt cooling device according to the fifth aspect is the core melt cooling device according to any one of the first to fourth aspects, and further, a sacrificial material concrete (sacrificial material) 52 is disposed inside the core melt receiving members 31, 31A. Thereby, the core melt 25A that has fallen onto the core melt receiving members 31, 31A is received by the sacrificial material concrete 52 and melted and mixed, thereby lowering the melting point and reducing the viscosity, and it can be cooled at an early stage.

[0057] The core melt cooling device according to the sixth aspect is the core melt cooling device according to any one of the first to fifth aspects, and further, the cooling water inflow portion has cooling water inflow holes 41, 43 or a cooling water inflow notch 42 provided in the side portion 31a of the core melt receiving members 31, 31A. Thereby, the structure can be simplified.

[0058] The core melt cooling device according to the seventh aspect is the core melt cooling device according to any one of the first to sixth aspects, and further, a cooling water replenishing mechanism 53 for replenishing cooling water to the cavity 19 is provided. Thereby, cooling water can always be ensured in the cavity 19, and the core melt 25A can be appropriately cooled over a predetermined period.

[0059] The nuclear power facility according to the eighth aspect includes a reactor containment vessel 11, a reactor 15 disposed inside the reactor containment vessel 11, and the core melt cooling devices 30, 30A according to any one of the first to seventh aspects. Thereby, even when the power supply in the nuclear power facility 10 is lost, the core melt cooling devices 30, 30A can quickly cool the core melt 25A that has flowed out from the reactor vessel 24, and the safety can be improved.

Explanation of Signs

[0060] 10 Nuclear power facility 11 Reactor containment vessel 12 Foundation part 13 Containment vessel main body 14 Structure 15 Reactor 16 Space part 17 Steam generator 18 Cooling water pipe 19 Cavity (water storage tank) 20 Cooling water pit 21 Cooling water injection device 22 Cooling water path 23 Cooling water pump 24 Reactor vessel 25 Core 25A Core melt 30, 30A Core melt cooling device 31, 31A Core melt receiving member 32, 33 Support member 41, 43 Cooling water inlet hole (cooling water inlet part) 42 Cooling water inlet notch (cooling water inlet part) 51 Guide mechanism 52 Sacrificial material concrete (sacrificial material) 53 Cooling water replenishment mechanism 54 Replenishment tank 55 Replenishment path 56 On-off valve

Claims

1. In a core melt cooling device for supporting a nuclear reactor by a structure installed at a base portion of a nuclear reactor containment vessel and cooling a core melt that falls from a lower portion of the nuclear reactor vessel, a water storage tank provided below the nuclear reactor vessel for storing cooling water; a core melt receiving member disposed inside the water storage tank and having a cooling water inlet portion provided at a side portion thereof; a support member that supports the core melt receiving member and is movably supported between a raised position and a lowered position according to the presence or absence of the core melt; A core melt cooling device comprising:

2. When the core melt receiving member is not receiving the core melt, the support member supports the core melt receiving member at the raised position where cooling water does not flow in from the cooling water inlet portion, and when the core melt receiving member receives the core melt, the support member supports the core melt receiving member at the lowered position where cooling water flows in from the cooling water inlet portion. The core melt cooling device according to claim 1.

3. The support member is disposed below the core melt receiving member and has a crushable beam that deforms when the core melt receiving member receives the core melt. The core melt cooling device according to claim 2.

4. A guide mechanism is provided for movably supporting the core melt receiving member along a vertical direction with respect to the water storage tank. The core melt cooling device according to claim 1.

5. A sacrificial material is disposed inside the core melt receiving member. The core melt cooling device according to claim 1.

6. The cooling water inlet portion has a cooling water inlet hole or a cooling water inlet notch provided at a side portion of the core melt receiving member. The core melt cooling device according to claim 1.

7. A cooling water replenishing mechanism for replenishing cooling water to the water storage tank is provided. The core melt cooling device according to claim 1.

8. A reactor containment vessel, A reactor disposed inside the reactor containment vessel, The core melt cooling device according to claim 1, and a nuclear power facility comprising the same.

Images