Reactor-core molten material treatment apparatus and nuclear facility

Abstract

To suppress diffusion of a core melt flowing out of a reactor vessel.SOLUTION: A reactor-core molten material treatment apparatus in which a nuclear reactor is supported by a structure installed on a base of a reactor containment vessel and a reactor-core molten material dropping from a lower portion of a reactor vessel is treated includes a cavity provided in a hollow shape in the base, a transfer passage having one end communicating with the cavity, a shielding chamber with which the other end of the transfer passage communicates, and a lead member disposed inside the shielding chamber and melted by the reactor-core molten material.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a core molten material treatment apparatus and a nuclear facility. [Background technology]

[0002] A reactor containment vessel is erected on solid ground such as bedrock, and a reactor is placed inside. The reactor is supported by a concrete structure provided at the base of the reactor containment vessel. In nuclear power facilities, a severe accident is assumed in which molten core material flows out of the reactor vessel. Since the molten core material melts the lower part of the reactor vessel and falls downward, a cavity is provided below the reactor vessel, which receives the molten core material and cools it with cooling water. An example of such nuclear power facility is described in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3150451 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional nuclear power facilities, if an accident occurs in which molten core material escapes from the reactor vessel, the molten core material that has fallen into the cavity is cooled by supplying cooling water. However, when cooling water is supplied to the molten core material, although the molten core material is cooled, it also spreads in the cavity. If the molten core material spreads in the cavity, not only is it difficult to deal with the molten core material after cooling, but it also poses the problem of making the post-processing of surrounding equipment difficult.

[0005] The present disclosure is intended to solve the above-mentioned problems, and aims to provide a core molten material treatment device and nuclear equipment that can suppress the diffusion of core molten material that has flowed out of a reactor vessel. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the disclosed core molten material treatment device has a reactor supported by a structure installed in the base of a reactor containment vessel, and treats core molten material that falls from the bottom of the reactor vessel, and includes a hollow cavity provided in the base, a transfer passage having one end connected to the cavity, a shielded chamber to which the other end of the transfer passage is connected, and a lead member that is placed inside the shielded chamber and melts due to the core molten material.

[0007] The nuclear facility of the present disclosure also includes a nuclear reactor disposed inside the reactor containment vessel, and a treatment device for the molten core. [Effects of the Invention]

[0008] According to the core molten material treatment device and nuclear facility of the present disclosure, it is possible to suppress the diffusion of core molten material that has flowed out of the reactor vessel. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing a nuclear facility according to this embodiment. [Figure 2] FIG. 2 is a schematic diagram showing the apparatus for treating molten core material according to this embodiment. [Figure 3] FIG. 3 is a schematic diagram showing the operation of the core molten material treatment device. [Figure 4] FIG. 4 is a schematic diagram showing the operation of the core molten material treatment device. [Figure 5] FIG. 5 is a schematic diagram showing the operation of the core molten material treatment device. [Figure 6] FIG. 6 is a schematic diagram showing the operation of the core molten material treatment device. DETAILED DESCRIPTION OF THE INVENTION

[0010] Preferred embodiments of the present disclosure will be described in detail below with reference to the drawings. Note that the present disclosure is not limited to these embodiments, and when there are multiple embodiments, the present disclosure also includes configurations that combine the embodiments. Furthermore, the components in the embodiments include those that can be easily imagined by a person skilled in the art, those that are substantially identical, and those that are within the so-called equivalent range.

[0011] <Nuclear equipment> FIG. 1 is a schematic diagram showing a nuclear facility according to this embodiment.

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

[0013] The reactor containment vessel 11 is placed on solid ground G such as bedrock. The reactor containment vessel 11 comprises a foundation 12 and a containment vessel main body 13. The foundation 12 is placed on the ground G, and the containment vessel main body 13 is erected on the foundation 12. The foundation 12 and the containment vessel main body 13 form an integrated structure. Inside the containment vessel main body 13, a structure 14 constructed of reinforced concrete or the like is provided. The structure 14 is placed inside the containment vessel main body 13, on top of the foundation 12.

[0014] The reactor 15 is disposed in the center of the containment vessel 11. The structure 14 defines a cylindrical space 16 in the center of the reactor containment vessel 11, and the reactor 15 is disposed in the space 16 and is suspended and supported by the structure 14 that forms the inner wall of the space 16. The reactor containment vessel 11 has a plurality of steam generators 17 disposed around the reactor 15. 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 cooling water piping 18.

[0015] The reactor containment vessel 11 has a cavity 19 defined below the reactor 15. The cavity 19 receives and cools the molten core that falls from the reactor 15. The reactor containment vessel 11 has a cooling water pit 20 for storing cooling water provided in the base 12, and a cooling water injection device 21 provided on top 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 attached to the top of the reactor vessel body. The reactor vessel 24 is provided with an inlet nozzle at the top that supplies light water (coolant) as primary cooling water, and an outlet nozzle that discharges the light water. Cooling water piping 18 from the steam generator 17 is connected to the inlet nozzle and outlet nozzle of the reactor vessel 24, respectively. The core 25 disposed inside the reactor vessel 24 is configured with a plurality of fuel assemblies. The fuel assemblies are configured with a large number of fuel rods bundled in a lattice pattern by support lattices. In addition to the large number of fuel rods, a plurality of control rods that control the output of the reactor 15 are disposed in the core 25.

[0017] In the nuclear reactor 15, neutrons are emitted as the nuclear fuel that makes up the reactor core 25 undergoes nuclear fission, and light water, which acts as a moderator and primary coolant, reduces the kinetic energy of the emitted fast neutrons to thermal neutrons, making it easier for new nuclear fission to occur and also absorbs the generated heat to cool the reactor. At this time, the number of neutrons generated in the reactor core 25 can be adjusted by inserting control rods into the reactor core 25, thereby adjusting the output of the reactor 15.

[0018] The steam generator 17 is connected via steam piping to a steam turbine provided outside the reactor containment vessel 11. A power generator is connected to the steam turbine. The steam generator 17 generates steam by exchanging heat between high-temperature primary cooling water and secondary cooling water supplied from the reactor 15. The generated steam is sent to and drives the steam turbine, which generates electricity. The steam that drives the steam turbine is returned to the steam generator 17 after being cooled.

[0019] <Processing equipment for treating molten core material> FIG. 2 is a schematic diagram showing the apparatus for treating molten core material according to this embodiment.

[0020] 1 and 2, a nuclear facility 10 includes a molten core treatment device (hereinafter simply referred to as a cooling device) 30. The reactor 15 is supported by a structure 14 installed on a base 12 of a containment vessel 11, and the treatment device 30 treats the molten core that falls from the bottom of a reactor vessel 24 that constitutes the reactor 15. Specifically, the treatment device 30 shields and cools the molten core that falls from the bottom of the reactor vessel 24.

[0021] The processing device 30 includes a cavity 19 , a transfer passage 31 , a shielded chamber 32 , and a lead member 33 .

[0022] The cavity 19 is hollow and provided in the foundation 12 located below the reactor 15. The cavity 19 communicates with the shielded chamber 32 through a transfer passage 31. That is, one end of the transfer passage 31 communicates with the bottom of the cavity 19, and the other end communicates with the side of the shielded chamber 32. The transfer passage 31 is generally L-shaped and has a vertical passage 31a and an inclined passage 31b. Note that the vertical passage 31a may be a horizontal passage. The upper end of the vertical passage 31a opens to the bottom of the cavity 19, and the lower end communicates with one end of the inclined passage 31b. The other end of the inclined passage 31b opens to the side of the shielded chamber 32. The transfer passage 31 is a through-hole provided through the foundation 12. Sacrificial concrete 41 is provided at the bottom of cavity 19 and at the top of vertical passage 31a in transfer passage 31. Sacrificial concrete 41 is a sacrificial material that lowers the melting point of the molten core material to reduce its viscosity, and is not limited to concrete. Note that refractory material (e.g., metal piping) may be arranged on the inner wall surface of transfer passage 31.

[0023] The shielding chamber 32 is hollow and provided in the foundation 12 located below the reactor 15. The shielding chamber 32 is a partitioned room that functions as a space that suppresses the spread of molten core material. The shielding chamber 32 has a floor 32a, a ceiling 32b, one side 32c, and the other side 32d. The floor 32a is horizontal, and sacrificial concrete 42 is provided on top. The sacrificial concrete 42 has a horizontal plate shape. The ceiling 32b is horizontal and faces above the floor 32a. The one side 32c is connected to the other end of the inclined passage 31b in the transfer passage 31. The other side 32d is located on the opposite side from the one side 32c.

[0024] The lead member 33 is disposed inside the shielding chamber 32 and melted by the molten core. The lead member 33 includes a first lead member 43, a second lead member 44, and a third lead member 45. The first lead member 43 is provided on the floor 32a of the shielding chamber 32. That is, the first lead member 43 is disposed above the sacrificial material concrete 42 and has a horizontal plate shape. That is, the sacrificial material concrete 42 is disposed between the floor 32a of the shielding chamber 32 and the first lead member 43. However, the sacrificial material concrete 42 may be disposed above the first lead member 43. The second lead member 44 is provided on the ceiling 32b of the shielding chamber 32. The second lead member 44 has a horizontal plate shape. The second lead member 44 may be fixed to the ceiling 32b or may be suspended from the ceiling 32b. The third lead member 45 is provided in the inclined passage 31b of the transfer passage 31. The third lead member 45 is provided at the bottom portion of the inclined passage 31b.

[0025] Although the first lead member 43, the second lead member 44, and the third lead member 45 are provided as the lead member 33, at least one of the first lead member 43, the second lead member 44, and the third lead member 45 may be provided. The first lead member 43, the second lead member 44, and the third lead member 45 each have an integral structure, but they may also have a separate structure. When the first lead member 43, the second lead member 44, and the third lead member 45 have a separate structure, the separate lead members are preferably arranged in close contact with each other, but they may also be spaced apart. The first lead member 43 and the second lead member 44 have a uniform thickness, but the thickness of the central portion may be thicker. Furthermore, lead members may be arranged on vertical walls of the shielded chamber 32, including the one side portion 32c and the other side portion 32d.

[0026] The treatment device 30 includes a cavity 19, a transfer passage 31, a shielded chamber 32, a lead member 33, a water tank 51, a jetting portion 52, and a heat transfer device 53.

[0027] The water tank 51 is provided below the shielded chamber 32 and stores cooling water therein. The water tank 51 is a hollow tank that is substantially sealed. The shielded chamber 32 has a through-hole 32e that penetrates the floor 32a on the other side 32d side. The shielded chamber 32 also has a vertical guide member 61 and a horizontal guide 62 that face the other side 32d, thereby providing an ejection passage 63 that communicates between the water tank 51, the through-hole 32e, and the shielded chamber 32. The ejection portion 52 communicates with the ejection passage 63 and can eject cooling water flowing from the water tank 51 through the ejection passage 63 into the shielded chamber 32. The ejection portion 52 ejects cooling water horizontally toward the one side 32c of the shielded chamber 32. It should be noted that the shielding chamber 32 may be provided with a plurality of jetting portions 52 and jetting passages 54 not only on the other side portion 32d side but also at other positions.

[0028] The heat transfer device 53 transfers the pressure of the molten core transported to the shielding chamber 32 to the cooling water in the water tank 51, causing the cooling water in the water tank 51 to expand and be ejected from the ejection part 52. The heat transfer device 53 has a water storage pit 71, a gas passage 72, and a cooling water passage 73.

[0029] The water storage pit 71 stores cooling water therein. The water storage pit 71 is a hollow tank that is substantially sealed. One end of the gas passage 72 is connected to the shielding chamber 32, and the other end is connected to the water storage pit 71. That is, one end of the gas passage 72 opens to the ceiling 32b of the shielding chamber 32. The other end of the gas passage 72 enters the inside from the side of the water storage pit 71 and opens downward. The gas passage 72 supplies gas from the shielding chamber 32 to the water storage pit 71 by the pressure of the molten core. The gas passage 72 is provided with a check valve 81 that prevents gas from flowing from the water storage pit 71 to the shielding chamber 32.

[0030] The cooling water passage 73 has one end connected to the water storage pit 71 and the other end connected to the water storage tank 51. That is, one end of the cooling water passage 73 opens to the bottom of the water storage pit 71. The other end of the cooling water passage 73 opens to the bottom of the water storage tank 51. The cooling water passage 73 supplies the cooling water from the water storage pit 71 to the water storage tank 51. The cooling water passage 73 is provided with an open valve 82 that opens in response to the pressure of the cooling water in the water storage pit 71. It is preferable to use a check valve with a rupture disk as the open valve 82. The check valve prevents backflow of cooling water from the water storage tank 51 to the water storage pit 71. That is, when the pressure of the cooling water in the water storage pit 71 reaches a predetermined pressure, the open valve 82 opens when the rupture disk ruptures.

[0031] The water storage pit 71 is also provided with a partition wall 83. The partition wall 83 is arranged vertically at the bottom of the water storage pit 71. The partition wall 83 separates the communication portion 72a, through which the gas passage 72 communicates, from the communication portion 73a, through which the cooling water passage 73 communicates. In other words, the partition wall 83 prevents foreign matter that has entered the water storage pit 71 from the communication portion 72a of the gas passage 72, from entering the communication portion 73a of the cooling water passage 73.

[0032] The water storage pit 71 is provided with a cooling mechanism 91 that cools the cooling water. The cooling mechanism 91 has a cooling cooler 92, a circulation passage 93, and a pump 94. The circulation passage 93 has an intermediate portion disposed inside the cooling cooler 92, one end communicating with the upper portion of the water storage pit 71, and the other end communicating with the lower portion of the water storage pit 71. The pump 94 is provided in the circulation passage 93. Therefore, when the pump 94 is operated, the cooling water in the upper portion of the water storage pit 71 flows into the circulation passage 93, is cooled by the cooling cooler 92, and is returned to the lower portion of the water storage pit 71. Note that the pump 94 may be omitted from the circulation passage 93 if natural circulation of the cooling water is possible.

[0033] The water storage pit 71 is provided with a cooling water replenishment mechanism 95 that replenishes cooling water. The cooling water replenishment mechanism 95 is composed of a cooling water replenishment passage 96 and an on-off valve 97. The on-off valve 97 is preferably manual. By opening the on-off valve 97, the cooling water replenishment mechanism 95 can replenish cooling water from a replenishment tank (not shown) to the water storage pit 71 through the cooling water replenishment passage 96 by free fall. The water storage pit 71 is also provided with a safety valve 98 that opens when the internal pressure exceeds a preset specified pressure.

[0034] <Method for treating molten core material> 3 to 6 are schematic diagrams showing the operation of the core molten material treatment device.

[0035] As shown in Fig. 2, it is assumed that a severe accident occurs in the nuclear facility 10, resulting in a core damage accident due to core meltdown. At this time, as shown in Fig. 3, the lower part of the reactor vessel 24 of the reactor 15 is damaged, and molten core material 25A, which is the melted core 25, flows out. The molten core material 25A that flows out from the lower part of the reactor vessel 24 falls toward the sacrificial concrete 41 in the cavity 19. The sacrificial concrete 41 receives the molten core material 25A that falls from the lower part of the reactor vessel 24 at its center. The molten core material 25A includes the molten core 25 and reactor internals that melt along with the molten core 25.

[0036] The sacrificial material concrete 41 melts and mixes with the molten core material 25A, thereby lowering the melting point of the molten core material 25A and reducing its viscosity. That is, the molten core material 25A that falls onto the sacrificial material concrete 41 melts the sacrificial material concrete 41 with its own heat and mixes with the molten sacrificial material concrete 41, lowering its temperature and reducing its viscosity. Then, as shown in Fig. 4, the molten core material 25B mixed with the sacrificial material concrete 41 falls from the melted part of the sacrificial material concrete 41 into the vertical passage 31a of the transfer passage 31, and flows from the vertical passage 31a to the inclined passage 31b.

[0037] As molten core material 25B flows through inclined passage 31b, it comes into contact with third lead member 45 and melts third lead member 45. Molten core material 25B has a temperature of 1000°C or higher and melts third lead member 45, which has a melting point of approximately 300°C. Molten core material 25C mixed with third lead member 45 flows through inclined passage 31b while melting third lead member 45, and is transported to shielded chamber 32 where it spreads.

[0038] As shown in Fig. 5, the molten core material 25C that flows into the shielding chamber 32 is received by the first lead members 43. The molten core material 25C comes into contact with the first lead members 43 and is mixed with the melted first lead members 43. When the first lead members 43 melt, the molten core material 25C comes into contact with the sacrificial concrete 42, melts and mixes with the sacrificial concrete 42, and further decreases in temperature and viscosity. In addition, the shielding chamber 32 is heated to a high temperature by the heat of the molten core material 25C, melting the second lead members 44 on the ceiling 32b. When the second lead members 44 melt, they drop toward the molten core material 25C on the first lead members 43.

[0039] As shown in FIG. 6 , the molten core material 25C melts and mixes with the sacrificial concrete 42 to become the molten core material 25D. At this time, the first lead member 43, the second lead member 44, and the third lead member 45, which are the lead members 33, all melt. The molten core material 25D contains fuel such as uranium and has a higher specific gravity than the lead member 33 (11.34). Therefore, the lead members 33 cover the molten core material 25D from above to prevent diffusion, and the molten core material 25D is shielded by the lead members 33. In this case, the total amount of the lead members 33 is preferably equal to or greater than the amount that can cover the molten core material 25D. Furthermore, the lead members 33 melted in the shielded chamber 32 block the communication portion of the transfer passage 31 in the shielded chamber 32, so the shielded chamber 32 becomes a substantially closed space, preventing the molten core material 25D from diffusing to the outside. In this case, it is preferable that the total amount of the lead member 33 is at least an amount that can block the communication portion of the transfer passage 31 .

[0040] Furthermore, when the molten core 25C is transferred to the shielding chamber 32, the temperature of the shielding chamber 32 rises, causing the second lead member 44 to melt and drop, thereby connecting the shielding chamber 32 to the gas passage 72. As the temperature of the shielding chamber 32 rises, the internal pressure also rises. Then, in the shielding chamber 32, the pressurized air is supplied to the water storage pit 71 through the gas passage 72, and the pressure in the water storage pit 71 also rises. As the internal pressure rises, the water storage pit 71 pushes the stored cooling water into the cooling water passage 73. Then, when the pressure of the cooling water in the water storage pit 71 exceeds a predetermined pressure, it ruptures the release valve (rupture disk) 82 of the cooling water passage 73, causing it to open.

[0041] When the release valve 82 is opened, the cooling water in the water storage pit 71 flows from the cooling water passage 73 to the water storage tank 51, and the ejection part 52 ejects the cooling water toward the molten core 25C in the shielded chamber 32. Then, the molten core 25C is cooled by the cooling water ejected from the ejection part 52.

[0042] When the pressurized air in the shielded chamber 32 is supplied to the water storage pit 71, the air contains gas resulting from evaporation of the lead members 33, which becomes foreign matter and enters the water storage pit 71. However, the water storage pit 71 is provided with a partition wall 83, which prevents the foreign matter that has entered the water storage pit 71 from entering the cooling water passage 73.

[0043] Furthermore, the temperature of the cooling water in the water storage pit 71 rises due to the high-temperature, high-pressure air supplied from the shielded chamber 32. At this time, the cooling mechanism 91 operates to cool the cooling water in the water storage pit 71. When the cooling water in the water storage pit 71 decreases, the cooling water replenishment mechanism 95 is activated to replenish the cooling water in the water storage pit 71. Furthermore, when the pressure in the water storage pit 71 rises and exceeds the specified pressure, the safety valve 98 is opened.

[0044] [Effects of this embodiment] The core molten material treatment device of the first embodiment has a reactor 15 supported by a structure 14 installed on the base 12 of a reactor containment vessel 11, and is a core molten material treatment device 30 that cools core molten material 25A falling from the bottom of a reactor vessel 24.The device is equipped with a cavity 19 formed in a hollow shape in the base 12, a transfer passage 31 whose one end communicates with the cavity 19, a shielded chamber 32 whose other end communicates with the transfer passage 31, and a lead member 33 arranged inside the shielded chamber 32 that melts with the core molten material 25A, 25B, 25C, and 25D.

[0045] According to the apparatus for treating molten core material according to the first aspect, when the lower part of reactor vessel 24 is damaged and molten core material 25A, which is molten core 25, falls, molten core material 25A is transferred from cavity 19 through transfer passage 31 to shielded chamber 32. Molten core material 25C transferred to shielded chamber 32 melts lead members 33. Lead members 33 cover and shield molten core material 25C due to the difference in specific gravity between them. As a result, diffusion of molten core materials 25A, 25B, 25C, and 25D that have flowed out of reactor vessel 24 can be suppressed.

[0046] The apparatus for treating molten core material according to the second aspect is the apparatus for treating molten core material according to the first aspect, further comprising: a first lead member 43 provided on the floor 32a of the shielded chamber 32; and a second lead member 44 provided on the ceiling 32b of the shielded chamber 32. This allows the first lead member 43 to receive the molten core material 25C transferred to the shielded chamber 32, and allows the molten second lead member 44 to fall toward the molten core material 25C on the first lead member 43, allowing the lead member 33 to appropriately cover the molten core material 25C.

[0047] The apparatus for treating molten core material according to the third embodiment is the apparatus for treating molten core material according to the second embodiment, and further includes a sacrificial material concrete (sacrificial material) disposed between the floor 32a of the shielded chamber 32 and the first lead member 43. This can reduce the temperature and viscosity of the molten core material 25C, allowing the molten core material 25C to be cooled quickly.

[0048] The apparatus for treating molten core material according to the fourth aspect is the apparatus for treating molten core material according to any one of the first to third aspects, and further includes a third lead member 45 provided in the transfer passage 31. This allows the molten core material 25C to come into contact with the third lead member 45 and melt before being transferred to the shielded chamber 32, and the molten core material 25C can be covered with the lead member 33 at an early stage.

[0049] A fifth aspect of the apparatus for treating molten core material is the apparatus for treating molten core material according to any one of the first to third aspects, and further includes a water tank 51 disposed below the shielded chamber 32 and storing cooling water, a jetting unit 52 capable of jetting the cooling water from the water tank 51 into the shielded chamber 32, and a heat transfer device 53 that transfers the pressure of the molten core material 25C transferred to the shielded chamber 32 to the cooling water in the water tank 51 and jets the cooling water from the jetting unit 52. As a result, the pressure of the molten core material 25C transferred to the shielded chamber 32 is transferred to the cooling water in the water tank 51 by the heat transfer device 53, and the jetting unit 52 jets the cooling water toward the molten core material 25C in the shielded chamber 32. Therefore, the molten core material 25C is cooled by the cooling water. As a result, even if power is lost in the nuclear facility 10, the molten core material 25A that has flowed out of the reactor vessel 24 can be cooled quickly.

[0050] The apparatus for treating molten core material according to the sixth aspect is the apparatus for treating molten core material according to the fifth aspect, and further includes heat transfer device 53 having a water storage pit 71 for storing cooling water, a gas passage 72 for supplying gas in shielded chamber 32 to water storage pit 71 by the pressure of molten core 25C, and a cooling water passage 73 for supplying cooling water in water storage pit 71 to water tank 51. This allows gas in shielded chamber 32 to be supplied to water storage pit 71 by gas passage 72, and cooling water in water storage pit 71 to be supplied to water tank 51 by cooling water passage 73, and cooling water can be appropriately supplied to shielded chamber 32 by the increase in pressure in shielded chamber 32.

[0051] The apparatus for treating molten core material according to the seventh aspect is the apparatus for treating molten core material according to the sixth aspect, further comprising a partition wall 83 provided in the water storage pit 71, which separates the communication section 72a, through which the gas passage 72 communicates, from the communication section 73a, through which the cooling water passage 73 communicates. As a result, foreign matter that has entered the water storage pit 71 from the shielded chamber 32 is blocked by the partition wall 83, thereby preventing the foreign matter from entering the cooling water passage 73.

[0052] The core molten material treatment apparatus according to the eighth aspect is the core molten material treatment apparatus according to the sixth or seventh aspect, further comprising a check valve 81 provided in the gas passage 72 to prevent flow from the water storage pit 71 to the shielded chamber 32. This makes it possible to prevent flow from the water storage pit 71 to the shielded chamber 32.

[0053] The ninth aspect of the apparatus for treating molten core material is the apparatus for treating molten core material according to any one of the sixth to eighth aspects, and furthermore, cooling water passage 73 is provided with release valve 82 that opens according to the pressure of the cooling water in water storage pit 71. This allows molten core material 25C to spread in shielded chamber 32 until the pressure of the cooling water in water storage pit 71 reaches a predetermined pressure, and by spraying cooling water at the predetermined pressure, molten core material 25C can be sprayed over a wide area in shielded chamber 32, thereby appropriately cooling molten core material 25C.

[0054] The apparatus for treating molten core material according to a tenth aspect is the apparatus for treating molten core material according to the ninth aspect, further comprising: the open valve 82 having a rupture disk. This simplifies the structure of the open valve 82. In this case, the open valve 82 is preferably a check valve having a rupture disk. The check valve can prevent backflow of cooling water from the shielded chamber 32 (water tank 51) to the water storage pit 71.

[0055] The molten core treatment device according to an eleventh aspect is the molten core treatment device according to any one of the sixth to tenth aspects, and further includes a cooling mechanism 91 that cools the cooling water in the water storage pit 71. This makes it possible to suppress a rise in the temperature of the cooling water and appropriately cool the molten core 25C.

[0056] The molten core treatment device according to the twelfth aspect is the molten core treatment device according to any one of the sixth to eleventh aspects, and further includes a cooling water replenishment mechanism 95 that replenishes cooling water to the water storage pit 71. This makes it possible to constantly ensure cooling water in the water storage pit 71, and to appropriately cool the molten core 25C for a predetermined period of time.

[0057] The thirteenth aspect of the apparatus for treating molten core material is the apparatus for treating molten core material according to any one of the sixth to eleventh aspects, and further includes a safety valve 98 that opens when the pressure in the water storage pit 71 exceeds a predetermined pressure. This makes it possible to prevent damage to the water storage pit 71.

[0058] The nuclear facility according to the fourteenth aspect includes a reactor containment vessel 11, a reactor 15 disposed inside the reactor containment vessel 11, and a molten core treatment device 30. As a result, even if power to the nuclear facility 10 is lost, the molten core treatment device 30 can suppress the diffusion of molten core 25A, 24B, 25C, and 25D that has flowed out of the reactor vessel 24. [Explanation of symbols]

[0059] 10 Nuclear equipment 11 Reactor containment vessel 12 Foundation 13. Containment vessel body 14 Structures 15 nuclear reactor 16 Space section 17 Steam Generator 18 Cooling water piping 19 Cavity 20 Cooling water pit 21 Cooling water injection device 22 Cooling water path 23 Cooling water pump 24 Reactor Vessel 25 reactor core 25A Core meltdown 30. Treatment equipment for molten core material 31 Transfer passage 32 Shielded room 33 Lead parts 41,42 Sacrificial concrete 43 1st lead member 44 2nd lead member 45 Third lead member 51 Water Tank 52 Spout part 53 Heat transfer equipment 61 Vertical guide member 62 Horizontal guide section 63 Spout passage 71 Water storage pit 72 Gas passage 73 Cooling water passage 81 Check valve 82 Release valve 83 Partition Wall 91 Cooling mechanism 92 Cooling Cooler 93 Circulation waterway 94 Pump 95 Cooling water replenishment mechanism 96 Cooling water refill passage 97 Shut-off valve 98 Safety valve

Claims

1. In a nuclear reactor core molten material treatment device, a nuclear reactor is supported by a structure installed in the base of a nuclear reactor containment vessel, and the device treats the nuclear reactor core molten material that falls from the bottom of the reactor vessel, a cavity provided in the base portion to have a hollow shape; a transfer passage having one end communicating with the cavity; a shielding chamber to which the other end of the transfer passage is connected; a lead member disposed inside the shielding chamber and melted by the molten core; A core molten material treatment device comprising:

2. The lead members include a first lead member provided on a floor portion of the shielded room and a second lead member provided on a ceiling portion of the shielded room. The apparatus for treating molten core material according to claim 1 .

3. a sacrificial material is disposed between a floor of the shielded chamber and the first lead member; The apparatus for treating molten core material according to claim 2 .

4. The lead member includes a third lead member provided in the transfer passage. The apparatus for treating molten core material according to claim 1 .

5. a water tank provided below the shielding chamber for storing cooling water; a jetting portion capable of jetting the cooling water in the water tank into the shielding chamber; and a heat transfer device that transfers the pressure of the molten core transferred to the shielding chamber to the cooling water in the water tank, thereby jetting the cooling water from the jetting portion. The apparatus for treating molten core material according to claim 1 .

6. the heat transfer device includes a water storage pit for storing cooling water, a gas passage for supplying gas in the shielding chamber to the water storage pit by pressure of the molten core, and a cooling water passage for supplying the cooling water in the water storage pit to the water tank. The apparatus for treating molten core material according to claim 5 .

7. The water storage pit is provided with a partition wall that separates a communication portion with which the gas passage communicates from a communication portion with which the cooling water passage communicates. The apparatus for treating molten core material according to claim 6 .

8. The gas passage is provided with a check valve that prevents gas from flowing from the water storage pit to the shielded chamber. The apparatus for treating molten core material according to claim 6 .

9. The cooling water passage is provided with an open valve that opens in response to the pressure of the cooling water in the water storage pit. The apparatus for treating molten core material according to claim 6 .

10. The release valve has a rupture disk. The apparatus for treating core molten material according to claim 9 .

11. A cooling mechanism is provided to cool the cooling water in the water storage pit. The apparatus for treating molten core material according to claim 6 .

12. a cooling water refilling mechanism for refilling the water storage pit with cooling water; The apparatus for treating molten core material according to claim 6 .

13. A safety valve is provided which opens when the pressure in the water storage pit exceeds a predetermined pressure. The apparatus for treating molten core material according to claim 6 .

14. A reactor containment vessel; a reactor disposed inside the reactor containment vessel; a core molten material treatment apparatus according to claim 1; A nuclear facility equipped with:

Images