Water injection device

Abstract

To make sure that cooled water is injected into a cavity room.SOLUTION: The present invention includes: a molten body 1 provided in a cavity room 102A for receiving a meltdown object below a nuclear reactor 101; and a valve mechanism 2 provided in a separate room 102B from a the cavity room 102A across a barrier wall 102C and connected to the molten body 1, the valve mechanism being capable of opening or closing a cooled water pipe 51 for sending cooled water into the cavity room 102A and opening the cooled water pipe 51 if the molten body 1 is molten.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a water injection device. [Background technology]

[0002] In nuclear power plants, a severe accident is assumed to occur in which molten core material leaks from the reactor vessel. If the molten core material falls into the cavity of the reactor containment vessel, serious damage to the structures that form the cavity may occur, which could lead to further damage. Therefore, measures must be taken to prevent serious damage to the reactor containment vessel.

[0003] For example, Patent Document 1 discloses a water injection device that injects water into a reactor containment vessel. This water injection device includes a flow path for supplying cooling water, a disk that closes the flow path, a swing arm that is connected to the disk and closes and opens the flow path with the disk, a weight that is connected to the swing arm via a swing lever, and a support member made of a low-melting-point alloy that supports the weight. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6753773 Summary of the Invention [Problem to be solved by the invention]

[0005] In the water injection device shown in Patent Document 1, all of the above components are arranged in the cavity chamber (lower dry well) into which the molten core falls. Therefore, if the disk, swing arm, swing lever, weight, etc. are affected by the heat of the molten core and their operation is hindered, there is a risk that it will become impossible to inject cooling water into the cavity chamber.

[0006] The present disclosure is intended to solve the above-mentioned problems, and has an object to provide a water injection device that can reliably inject cooling water into a cavity chamber. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, a water injection device according to one aspect of the present disclosure includes a molten body provided in a cavity chamber below a reactor containment vessel that receives molten core material, and a valve mechanism that is provided in a separate chamber from the cavity chamber via a partition wall but is connected to the molten body, and is configured to be able to open and close a cooling water pipe through which cooling water is sent to the cavity chamber, and that opens the cooling water pipe when the molten body melts. [Effects of the Invention]

[0008] The present disclosure allows cooling water to be reliably injected into the cavity. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing a water injection device. [Figure 2] FIG. 2 is a schematic side view showing the water injection device of the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view of an on-off valve of the valve mechanism in the water injection device of the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view of a valve opening portion of the valve mechanism in the water injection device of the first embodiment. [Figure 5] FIG. 5 is a cross-sectional view of an on-off valve of a valve mechanism in a water injection device of the second embodiment. [Figure 6] FIG. 6 is a cross-sectional view of a valve opening portion of a valve mechanism in a water injection device of the second embodiment. [Figure 7] FIG. 7 is a cross-sectional view of a valve mechanism in the water injection device of the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, the present disclosure is not limited to these embodiments. Furthermore, the components in the following embodiments include those that are easily replaceable by those skilled in the art, or those that are substantially identical.

[0011] FIG. 1 is a schematic diagram showing a water injection device.

[0012] The water injection device 10 is for cooling the molten core material with cooling water in the event that the molten core material flows out of the reactor vessel 101 in the event of a severe accident at the nuclear power plant.

[0013] The reactor vessel 101 is contained inside a highly airtight and robust reactor containment vessel 102. The reactor containment vessel 102 defines a cavity chamber 102A below the reactor vessel 101. The reactor containment vessel 102 also defines a separate chamber 102B at a position away from the bottom of the reactor vessel 101, which is isolated from the cavity chamber 102A by a partition wall 102C. Because the separate chamber 102B is isolated from the reactor vessel 101, the influence of the molten core is extremely low.

[0014] The water injection device 10 includes a molten mass 1 and a valve mechanism 2, 1002, 2002.

[0015] The molten body 1 is made of a material that melts with the core molten material and is formed as a long body such as a wire, rod, or chain. One end of the molten body 1 is placed in the cavity chamber 102A and is fixed to a fixing part 11 that is fixed to the floor of the cavity chamber 102A, for example. The other end of the molten body 1 passes through the partition wall 102C and reaches the separate chamber 102B, where it is connected to the valve mechanism 2, 1002, 2002.

[0016] The valve mechanisms 2, 1002, and 2002 are configured to open and close a cooling water pipe 51 through which cooling water is supplied to the cavity chamber 102A. The cooling water pipe 51 is mainly disposed in the separate chamber 102B and connected to a tank (not shown). The tank stores cooling water. The cooling water pipe 51 passes through the partition wall 102C, and a water inlet 51a is disposed in the cavity chamber 102A. Therefore, the cooling water pipe 51 can supply cooling water from the tank to the cavity chamber 102A through the water inlet 51a. The cooling water pipe 51 is also provided with an opening / closing mechanism 52, which opens and closes the supply of cooling water to the water inlet 51a. The valve mechanisms 2, 1002, and 2002 are disposed downstream of the opening / closing mechanism 52 with respect to the cooling water pipe 51. In other words, the opening / closing mechanism 52 is disposed upstream of the valve mechanisms 2, 1002, and 2002 in the cooling water pipe 51. The opening and closing mechanism 52 is normally in a state in which it opens the cooling water pipe 51, and is set to a state in which it closes the cooling water pipe 51 as necessary, such as during maintenance of the valve mechanisms 2, 1002, and 2002. The valve mechanisms 2, 1002, and 2002 are configured to open the cooling water pipe 51 and send cooling water to the cavity chamber 102A when the molten mass 1 melts due to the molten core in the cavity chamber 102A.

[0017] The valve mechanism 2 is a configuration example of the water injection device 10 of embodiment 1, the valve mechanism 1002 is a configuration example of the water injection device 10 of embodiment 2, and the valve mechanism 2002 is a configuration example of the water injection device 10 of embodiment 3. Details of the valve mechanisms 2, 1002, and 2002 of each embodiment will be described below.

[0018] [Embodiment 1] Fig. 2 is a schematic side view showing the water injection device of embodiment 1. Fig. 3 is a cross-sectional view of an on-off valve of the valve mechanism in the water injection device of embodiment 1. Fig. 4 is a cross-sectional view of a valve opening portion of the valve mechanism in the water injection device of embodiment 1.

[0019] The valve mechanism 2 includes an on-off valve 21 and a valve opening portion 22 .

[0020] The on-off valve 21 is provided in the cooling water pipe 51 and opens and closes the cooling water pipe 51. The on-off valve 21 has a valve casing 211 interposed in the cooling water pipe 51. The valve casing 211 has an inlet 211A through which cooling water can flow in and an outlet 211B through which cooling water can flow out. The valve casing 211 has a valve seat 211C between the inlet 211A and the outlet 211B inside. The on-off valve 21 also has a valve element 212A that can abut against or separate from the valve seat 211C. The valve element 212A in the first embodiment is a butterfly valve. That is, the valve element 212A is formed in a disk shape so that it can contact the inner surface of the circular valve seat 211C. A support shaft 212Aa extending radially is provided at the center of the valve element 212A. The valve element 212A has a support shaft 212Aa rotatably supported by the valve casing 211. In the on-off valve 21 configured in this manner, when the support shaft 212Aa rotates relative to the valve casing 211, the valve element 212A rotates about the support shaft 212Aa and is displaced between a position where it closes the valve seat 211C and a position where it opens the valve seat 211C. When the valve element 212A closes the valve seat 211C, the on-off valve 21 stops the passage of cooling water inside the valve casing 211 and closes the cooling water pipe 51. On the other hand, when the valve element 212A opens the valve seat 211C, the on-off valve 21 allows the passage of cooling water inside the valve casing 211 and opens the cooling water pipe 51. In addition, the on-off valve 21 has a water-stopping member 213 provided between the valve element 212A and the valve seat 211C. The waterproofing member 213 is made of ethylene propylene diene rubber (EPDM), which has excellent weather resistance, cold resistance, ozone resistance, aging resistance, and solvent resistance, and allows smooth contact and separation between the valve body 212A and the valve seat 211C.

[0021] The valve opening unit 22 is connected to the on-off valve 21 and maintains the on-off valve 21 in a closed state while opening the on-off valve 21. The valve opening unit 22 includes a drive mechanism 221, an opening mechanism 222, and an auxiliary mechanism 223.

[0022] The opening mechanism 222 operates the on-off valve 21 described above. That is, the opening mechanism 222 rotates the support shaft 212Aa of the on-off valve 21. In the opening mechanism 222, an operating shaft 222B is rotatably supported by an operating casing 222A. The operating casing 222A is connected to the valve casing 211, and the operating shaft 222B extends in the same direction as the support shaft 212Aa and is connected to the support shaft 212Aa. In the opening mechanism 222, an operating lever 222C is fixed to the operating shaft 222B inside the operating casing 222A. The operating shaft 222B rotates when the operating lever 222C moves around the operating shaft 222B. In the on-off valve 21, the support shaft 212Aa rotates in accordance with the rotation of the operating shaft 222B, and the valve element 212A rotates.

[0023] The drive mechanism 221 drives the opening mechanism 222. That is, the drive mechanism 221 moves the operating lever 222C. The drive mechanism 221 has a weight 221B disposed inside a drive casing 221A. The drive casing 221A is configured by closing upper and lower openings of a vertically continuous cylindrical side wall 221Aa with an upper plate 221Ab and a lower plate 221Ac. The weight 221B is configured with a main weight 221Ba, a secondary weight 221Bb, and a connecting member 221Bc. The main weight 221Ba is housed inside the drive casing 221A and is provided so as to be movable in the vertical direction. The secondary weight 221Bb is fixed to the lower part of the main weight 221Ba and extends downward in a rod-like shape, penetrating the lower plate 221Ac of the drive casing 221A and extending further downward. The portion where the secondary weight 221Bb penetrates the lower plate 221Ac is sealed with a seal ring 221Ad. The connecting member 221Bc is fixed to the top of the main weight 221Ba and extends upward in a rod shape, penetrating the upper plate 221Ab of the drive casing 221A and extending further upward. The portion where the connecting member 221Bc penetrates the upper plate 221Ab is sealed with a seal ring 221Ad. An eyebolt, to which the other end of the melt 1 is connected, is fixed to the tip of the connecting member 221Bc that extends outside the drive casing 221A.

[0024] As described above, the main weight 221Ba is provided inside the drive casing 221A so as to be able to move up and down. As the main weight 221Ba moves up and down, the secondary weight 221Bb also moves up and down. During its own movement, the secondary weight 221Bb always penetrates the lower plate 221Ac. The portion of the secondary weight 221Bb that penetrates the lower plate 221Ac penetrates the operating casing 222A of the opening mechanism 222 in the up and down direction. The secondary weight 221Bb is sealed to the operating casing 222A by a seal ring 222Aa. A support pin 221Bba is provided on the secondary weight 221Bb at a portion located inside the operating casing 222A. The support pin 221Bba is inserted into an elongated hole 222Ca formed in the operating lever 222C of the opening mechanism 222. 2, the operating lever 222C swings up and down as shown by the arrow R in Fig. 2 in accordance with the vertical movement of the main weight 221Ba and the secondary weight 221Bb. The movement of the operating lever 222C rotates the operating shaft 222B, and the on-off valve 21 is opened and closed.

[0025] Furthermore, as the main weight 221Ba moves up and down, the connecting member 221Bc also moves up and down. The connecting member 221Bc always penetrates the upper plate 221Ab during its own movement. The connecting member 221Bc has an eyebolt at its tip penetrating the upper plate 221Ab, to which the molten mass 1 is connected. One end of the molten mass 1 is fixed to the fixed portion 11 in the cavity chamber 102A so as to lift and support the main weight 221Ba and the secondary weight 221Bb upward against the loads of the main weight 221Ba and the secondary weight 221Bb during normal standby operation. Furthermore, when the main weight 221Ba and the secondary weight 221Bb are lifted upward, the on-off valve 21 is closed. Therefore, if the molten mass 1 melts due to the core melt in the cavity chamber 102A during a severe accident, the main weight 221Ba and the secondary weight 221Bb move downward. When the main weight 221Ba and the secondary weight 221Bb move downward, the on-off valve 21 opens, the cooling water pipe 51 opens, and the cooling water is sent to the cavity chamber 102A.

[0026] Here, the drive mechanism 221 contains a viscous material 221C such as oil below the main weight 221Ba inside the drive casing 221A. The viscous material 221C absorbs the impact when the main weight 221Ba and the secondary weight 221Bb move downward, and reduces the impact on the on-off valve 21.

[0027] Furthermore, drive mechanism 221 is provided with plug member 221D or support member 221E via a through hole formed in upper plate 221Ab of drive casing 221A. Plug member 221D closes the through hole. Plug member 221D is connected to drive casing 221A with connecting string 221Da so as to not separate from drive casing 221A when not in use. Support member 221E is a bolt that passes through the through hole and is screwed into main weight 221Ba, and supports main weight 221Ba on upper plate 221Ab of drive casing 221A. Support member 221E is connected to drive casing 221A with connecting string 221Ea so as to not separate from drive casing 221A when not in use. Plug member 221D is used normally during standby. During maintenance or the like, the support member 221E supports the drive casing 221A with the weight 221B positioned upward, preventing the main weight 221Ba and the secondary weight 221Bb from moving downward.

[0028] Incidentally, the size (weight) of the main weight 221Ba of the drive mechanism 221 can be changed in various ways. The specifications of the drive casing 221A are also changed in accordance with the change in the size (weight) of the main weight 221Ba. Furthermore, if the length (weight) of the secondary weight 221Bb needs to be changed in accordance with the change in the specifications of the main weight 221Ba, the shapes of the actuation casing 222A and the actuation lever 222C are changed based on the change in the range of movement of the secondary weight 221Bb in the up-down direction.

[0029] The auxiliary mechanism 223 has an auxiliary casing 223a connected to the working casing 222A of the opening mechanism 222 so as to communicate with it, and a pump 223b that pumps hydraulic oil into and out of the auxiliary casing 223a via piping 223c. The lower end of the secondary weight 221Bb, which penetrates the working casing 222A, reaches the inside of the auxiliary casing 223a. Therefore, when hydraulic oil is supplied to the auxiliary casing 223a, the secondary weight 221Bb is pushed upward, and the on-off valve 21 is closed via the secondary weight 221Bb. This auxiliary mechanism 223 prevents hydraulic oil from being supplied to the auxiliary casing 223a during normal standby operation. During maintenance of the water injection device 10, even when the other end of the molten mass 1 is detached and the main weight 221Ba is removed, the auxiliary mechanism 223 can supply and discharge hydraulic oil to and from the auxiliary casing 223a to move the secondary weight 221Bb up and down and open and close the on-off valve 21. That is, the auxiliary mechanism 223 supports the secondary weight 221Bb so as to place the on-off valve 21 in a closed state, and releases the support of the secondary weight 221Bb so as to place the on-off valve 21 in an open state.

[0030] Thus, the water injection device 10 of embodiment 1 includes a molten body 1 provided in a cavity chamber 102A below the reactor vessel 101 that receives the molten core material, and a valve mechanism 2 that is provided in a separate chamber 102B separated from the cavity chamber 102A by a partition wall 102C but is connected to the molten body 1, and is configured to be able to open and close a cooling water pipe 51 through which cooling water is sent to the cavity chamber 102A, and that opens the cooling water pipe 51 when the molten body 1 melts.

[0031] According to the water injection device 10 of this embodiment 1, by providing the valve mechanism 2 in a separate chamber 102B separated from the cavity chamber 102A by a partition wall 102C, it is possible to prevent the valve mechanism 2 from being exposed to the molten core, prevent the operation of the valve mechanism 2 from being hindered by the molten core, and operate the valve mechanism 2 by melting the molten mass 1. As a result, the water injection device 10 of embodiment 1 can reliably inject cooling water into the cavity chamber 102A.

[0032] In addition, in the water injection device 10 of embodiment 1, the valve mechanism 2 includes an on-off valve 21 that opens and closes the cooling water pipe 51, and a valve opening section 22 that is connected to the molten material 1 through a partition wall 102C and opens the on-off valve 21 when the molten material 1 melts, and the valve opening section 22 has a weight 221B that generates a load that puts the on-off valve 21 in an open state, and the molten material 1 hoists and supports the weight 221B against the load of the weight 221B so as to put the on-off valve 21 in a closed state.

[0033] According to the water injection device 10 of the first embodiment, the molten mass 1 is melted by the molten core material, so that the weight 221B moves downward and the on-off valve 21 can be put into an open state.

[0034] Moreover, in the water injection device 10 of the first embodiment, the valve mechanism 2 further includes an auxiliary mechanism 223 that supports the on-off valve 21 so that it is in the closed state, and releases the support so that the on-off valve 21 is in the open state.

[0035] According to the water injection device 10 of the first embodiment, for example, when installing or maintaining the weight 221B, the on-off valve 21 can be held in a closed state by the auxiliary mechanism 223 when the load of the weight 221B is not acting.

[0036] Furthermore, in the water injection device 10 of embodiment 1, the valve opening section 22 includes a drive casing 221A that supports the weight 221B so that it can move up and down, and a viscous body 221C that is housed inside the drive casing 221A and below the weight 221B.

[0037] According to the water injection device 10 of the first embodiment, the viscous body 221C can absorb the impact when the weight 221B falls, and the impact on the on-off valve 21 can be alleviated.

[0038] Furthermore, in the water injection device 10 of the first embodiment, the valve mechanism 2 is housed inside the valve casing 211, through which the valve body 212A and the valve seat 211C allow the cooling water to pass.

[0039] According to the water injection device 10 of this first embodiment, the valve body 212A and the valve seat 211C are protected by the valve casing 211, so that the action and operation of the valve body 212A and the valve seat 211C can be always ensured.

[0040] In the water injection device 10 of the first embodiment, the valve mechanism 2 has the valve element 212A formed of a butterfly valve.

[0041] According to the water injection device 10 of this first embodiment, a butterfly valve can be applied to the valve body 212A.

[0042] Moreover, in the water injection device 10 of the first embodiment, the valve mechanism 2 further includes a water blocking member 213 provided between the valve body 212A and the valve seat 211C.

[0043] According to the water injection device 10 of this embodiment 1, the action and operation of the valve body 212A and the valve seat 211C can be always ensured by the water stop member 213. The water injection device 10 of embodiment 1 is activated in the event of a severe accident, and since the on-off valve 21 must be maintained in a closed state under normal circumstances and the on-off valve 21 must be reliably opened in the event of a severe accident, it is necessary to always ensure the action and operation of the valve body 212A and the valve seat 211C.

[0044] Moreover, the water injection device 10 of the first embodiment further includes an opening / closing mechanism 52 provided on the cooling water pipe 51 upstream of the valve mechanism 2.

[0045] According to the water injection device 10 of this first embodiment, the opening and closing mechanism 52 can shut off the cooling water when the valve mechanism 2 is undergoing maintenance.

[0046] [Embodiment 2] Fig. 5 is a cross-sectional view of an on-off valve of the valve mechanism in the water injection device of embodiment 2. Fig. 6 is a cross-sectional view of a valve opening part of the valve mechanism in the water injection device of embodiment 2.

[0047] The valve mechanism 1002 includes an on-off valve 1021 and a valve opening portion 1022 .

[0048] The on-off valve 1021 is provided in the cooling water pipe 51 and opens and closes the cooling water pipe 51. The on-off valve 1021 has a valve casing 1211 interposed in the cooling water pipe 51. The valve casing 1211 has an inlet 1211A through which cooling water can flow in and an outlet 1211B through which cooling water can flow out. The valve casing 1211 has a valve seat 1211C inside it between the inlet 1211A and the outlet 1211B. The on-off valve 1021 also has a valve element 1212A that can abut against or separate from the valve seat 1211C. The valve element 1212A of the second embodiment is a check valve. That is, the valve element 1212A is formed in a disk shape so that it can contact the open end of the cylindrical valve seat 1211C. The valve element 1212A is provided with a support portion 1212Aa fixed to an operating shaft 1222B that rotatably penetrates the valve casing 1211. The support portion 1212Aa is provided integrally with a support arm 1212Ab provided on the side of the valve element 1212A opposite to the surface facing the valve seat 1211C. In the on-off valve 1021 configured in this manner, as the operating shaft 1222B rotates relative to the valve casing 1211, the valve element 1212A rotates about the operating shaft 1222B via the support portion 1212Aa and the support arm 1212Ab, and is displaced between a position that closes the valve seat 1211C and a position that opens the valve seat 1211C. When the valve element 1212A closes the valve seat 1211C, the on-off valve 1021 stops the passage of cooling water inside the valve casing 1211 and closes the cooling water pipe 51. Meanwhile, when the valve element 1212A of the on-off valve 1021 opens the valve seat 1211C, cooling water is permitted to pass through the valve casing 1211, thereby opening the cooling water pipe 51. When the valve element 1212A of the on-off valve 1021 is in a position where it closes the valve seat 1211C, the pressure of the cooling water flowing in from the inlet 1211A of the valve casing 1211 presses the valve element 1212A in a direction that closes the valve seat 1211C, thereby maintaining the closed state. The on-off valve 1021 is also provided with a water-stopping member 1213 between the valve element 1212A and the valve seat 1211C. The water-stopping member 1213 is made of ethylene propylene diene rubber (EPDM), which has excellent weather resistance, cold resistance, ozone resistance, aging resistance, and solvent resistance, and allows smooth contact and separation between the valve element 1212A and the valve seat 1211C.Moreover, the on-off valve 1021 is formed in the valve casing 1211 so that the opening diameter D1 of the valve seat 1211C is smaller than the opening diameter D2 of the inlet 1211A.

[0049] Furthermore, valve casing 1211 has opening 1211D formed at a position overlooking valve seat 1211C. Opening 1211D is opened and closed by cover member 1211E. Opening 1211D is normally closed by cover member 1211E during standby. Furthermore, opening 1211D is opened by removing cover member 1211E during maintenance or the like, allowing inspection of valve element 1212A and valve seat 1211C. Furthermore, valve casing 1211 is provided therein with stopper 1211F that abuts valve element 1212A when valve element 1212A opens valve seat 1211C, preventing excessive movement.

[0050] The valve opening unit 1022 is connected to the on-off valve 1021 and maintains the on-off valve 1021 in a closed state while opening the on-off valve 1021. The valve opening unit 1022 includes a drive mechanism 1221 and an opening mechanism 1222.

[0051] The opening mechanism 1222 operates the on-off valve 1021 described above. That is, the opening mechanism 1222 rotates the valve element 1212A via the support portion 1212Aa and the support arm 1212Ab of the on-off valve 1021. The opening mechanism 1222 has an operating shaft 1222B. The operating shaft 1222B penetrates the valve casing 1211 and is rotatably provided. The opening mechanism 1222 is configured by levers 1222C, each of which has its base end fixed to both ends of the operating shaft 1222B penetrating the valve casing 1211, and each of which has weights 1221B fixed to its tip. The opening mechanism 1222 also has a connecting member 1222D that connects the levers 1222C. The connecting member 1222D may connect the weights 1221B fixed to the levers 1222C. In this opening mechanism 1222, each lever 1222C rotates around an operating shaft 1222B. In the on-off valve 1021, the valve element 1212A rotates via a support portion 1212Aa and a support arm 1212Ab as the operating shaft 1222B rotates. Therefore, the valve element 1212A of the on-off valve 1021 swings as shown by arrow R in FIG. 5 as the operating shaft 1222B rotates. The on-off valve 1021 is opened and closed by the swing of the valve element 1212A.

[0052] The drive mechanism 1221 is made up of the weights 1221B. Each weight 1221B can rotate each lever 1222C downward by its own weight. The other end of the melt 1 is connected to each weight 1221B or each lever 1222C.

[0053] One end of the molten mass 1 is fixed to the fixed part 11 in the cavity chamber 102A so as to lift and support the weight 1221B upward against the load of the weight 1221B during normal standby operation. When the weight 1221B is lifted upward, the on-off valve 1021 is closed. Therefore, if the molten mass 1 melts in the cavity chamber 102A due to the molten core material in the event of a severe accident, the on-off valve 1021 moves downward. When the weight 1221B moves downward, the on-off valve 1021 opens, opening the cooling water pipe 51 and supplying cooling water to the cavity chamber 102A.

[0054] Thus, the water injection device 10 of embodiment 2 includes a molten body 1 provided in a cavity chamber 102A below the reactor vessel 101 that receives the molten core material, and a valve mechanism 1002 that is provided in a separate chamber 102B separated from the cavity chamber 102A by a partition wall 102C but is connected to the molten body 1, is configured to be able to open and close a cooling water pipe 51 through which cooling water is sent to the cavity chamber 102A, and opens the cooling water pipe 51 when the molten body 1 melts.

[0055] According to the water injection device 10 of this embodiment 2, by providing the valve mechanism 1002 in a separate chamber 102B separated from the cavity chamber 102A by a partition wall 102C, it is possible to prevent the valve mechanism 1002 from being exposed to the molten core, prevent the operation of the valve mechanism 1002 from being hindered by the molten core, and operate the valve mechanism 1002 by the melting of the molten mass 1. As a result, the water injection device 10 of embodiment 2 can reliably inject cooling water into the cavity chamber 102A.

[0056] In addition, in the water injection device 10 of embodiment 2, the valve mechanism 1002 includes an on-off valve 1021 that opens and closes the cooling water pipe 51, and a valve opening section 1022 that is connected to the molten material 1 through a partition wall 102C and opens the on-off valve 1021 when the molten material 1 melts, and the valve opening section 1022 has a weight 1221B that generates a load that puts the on-off valve 1021 in an open state, and the molten material 1 suspends and supports the weight 1221B against the load of the weight 1221B so as to put the on-off valve 1021 in a closed state.

[0057] According to the water injection device 10 of the second embodiment, the molten mass 1 is melted by the molten core material, so that the weight 1221B moves downward and the on-off valve 1021 can be put into an open state.

[0058] In addition, in the water injection device 10 of embodiment 2, the valve mechanism 1002 further includes levers 1222C fixed to both ends of an operating shaft 1222B that supports the opening and closing of the on-off valve 1021 and to which weights 1221B are respectively attached, and a connecting member 1222D that connects each lever 1222C or each weight 1221B.

[0059] According to the water injection device 10 of the second embodiment, by connecting each lever 1222C or each weight 1221B with the connecting member 1222D, it is possible to prevent the occurrence of twisting of the operating shaft 1222B. As a result, the water injection device 10 of the second embodiment can reliably open and close the on-off valve 1021, and can reliably inject cooling water into the cavity chamber 102A.

[0060] In the water injection device 10 of the second embodiment, the valve mechanism 1002 is housed inside the valve casing 1211, through which the valve body 1212A and the valve seat 1211C allow the cooling water to pass.

[0061] According to the water injection device 10 of this second embodiment, the valve body 1212A and the valve seat 1211C are protected by the valve casing 1211, so that the action and operation of the valve body 1212A and the valve seat 1211C can be always ensured.

[0062] Furthermore, in the water injection device 10 of the second embodiment, the valve mechanism 1002 has a valve element 1212A that is a check valve.

[0063] According to the water injection device 10 of this second embodiment, a check valve can be applied to the valve body 1212A.

[0064] Furthermore, in the water injection device 10 of the second embodiment, the valve mechanism 1002 is formed so that the opening diameter D1 of the valve seat 1211C is smaller than the opening diameter D2 of the inlet 1211A of the valve casing 1211.

[0065] According to the water injection device 10 of the second embodiment, the water pressure of the cooling water flowing in from the inlet 1211A of the valve casing 1211 can be made relatively small at the position of the valve seat 1211C. As a result, the water injection device 10 of the second embodiment can set the operating force (load of the weight 1221B) that opens the valve body 1212A to a small value, thereby enabling the device to be made more compact.

[0066] Moreover, in the water injection device 10 of the second embodiment, the valve mechanism 1002 further includes a water blocking member 1213 provided between the valve body 1212A and the valve seat 1211C.

[0067] According to the water injection device 10 of this embodiment 2, the action and operation of the valve body 1212A and the valve seat 1211C can be always ensured by the water stop member 1213. The water injection device 10 of embodiment 2 is operated in the event of a severe accident, and since the on-off valve 1021 must be kept closed under normal circumstances and must be reliably opened in the event of a severe accident, it is necessary to always ensure the action and operation of the valve body 1212A and the valve seat 1211C.

[0068] The water injection device 10 of the second embodiment further includes an opening / closing mechanism 52 provided on the cooling water pipe 51 upstream of the valve mechanism 2 .

[0069] According to the water injection device 10 of the second embodiment, the cooling water can be stopped by the opening and closing mechanism 52 during maintenance of the valve mechanism 1002.

[0070] [Embodiment 3] FIG. 7 is a cross-sectional view of a valve mechanism in the water injection device of the third embodiment.

[0071] The valve mechanism 2002 includes an on-off valve 2021 and a valve opening portion 2022 .

[0072] The on-off valve 2021 is provided in the cooling water pipe 51 and opens and closes the cooling water pipe 51. The on-off valve 2021 has a valve casing 2211 interposed in the cooling water pipe 51. The valve casing 2211 has an inlet 2211A through which cooling water can flow in and an outlet 2211B through which cooling water can flow out. The valve casing 2211 has a valve seat 2211C inside it between the inlet 2211A and the outlet 2211B. The on-off valve 2021 also has a valve element 2212A that can abut against or be separated from the valve seat 2211C. The valve element 2212A of the third embodiment is a gate valve. That is, the valve element 2212A is formed to come into contact with a valve seat 2211C formed on the inner periphery of the valve casing 2211 to gate the valve casing 2211. The valve element 2212A is provided on one side with a support shaft 2212Aa extending in the radial direction of the valve casing 2211. The valve element 2212A is supported by the support shaft 2212Aa so that the support shaft 2212Aa can slide radially relative to the valve casing 2211. In the on-off valve 2021 configured in this manner, the support shaft 2212Aa slides relative to the valve casing 2211, causing the valve element 2212A to move radially and be displaced between a position where the valve seat 2211C is closed and a position where the valve seat 2211C is opened. When the valve element 2212A closes the valve seat 2211C, the on-off valve 2021 stops the passage of cooling water inside the valve casing 2211 and closes the cooling water pipe 51. On the other hand, when the valve element 2212A opens the valve seat 2211C, the on-off valve 2021 allows cooling water to pass inside the valve casing 2211 and opens the cooling water pipe 51. Furthermore, the on-off valve 2021 is provided with a water-stopping member 2213 between the valve body 2212A and the valve seat 2211C. The water-stopping member 2213 is made of ethylene propylene diene rubber (EPDM), which has excellent weather resistance, cold resistance, ozone resistance, aging resistance, and solvent resistance, and allows the valve body 2212A and the valve seat 2211C to smoothly contact and separate from each other.

[0073] The valve opening unit 2022 is connected to the on-off valve 2021, and maintains the on-off valve 2021 in a closed state while opening the on-off valve 2021. The valve opening unit 2022 includes a drive mechanism 2221, an opening mechanism 2222, and an auxiliary mechanism 2223.

[0074] The opening mechanism 2222 operates the on-off valve 2021 described above. That is, the opening mechanism 2222 slides the support shaft 2212Aa of the on-off valve 2021. The opening mechanism 2222 has an operating shaft 2222B slidably supported by an operating casing 2222A. The operating casing 2222A is connected to the valve casing 2211, and the operating shaft 2222B extends in the same direction as the support shaft 2212Aa and is connected to the support shaft 2212Aa. The opening mechanism 2222 is provided with sensors 2211Ga and 2211Gb outside the operating casing 2222A. The operating shaft 2222B protrudes outside the operating casing 2222A and is provided with detection pieces 2222Ba that are detected by the sensors 2211Ga and 2211Gb. Therefore, the sliding movement of the operating shaft 2222B in one direction is detected by the sensor 2211Ga, and the sliding movement of the operating shaft 2222B in the other direction is detected by the sensor 2211Gb.

[0075] The drive mechanism 2221 drives the release mechanism 2222. That is, the drive mechanism 2221 slides the operating shaft 2222B. The drive mechanism 2221 has an elastic member 2221B disposed inside a drive casing 2221A. In this embodiment, the elastic member 2221B is configured as a compression coil spring, and is provided so as to be able to expand and contract in the direction of sliding movement of the operating shaft 2222B. One end (upper end) of the elastic member 2221B in the expansion and contraction direction is provided so as to be able to come into contact with the pressing member 2221E, and the other end (lower end) in the expansion and contraction direction is provided so as to be able to come into contact with the bottom plate 2221Aa of the drive casing 2221A. The elastic member 2221B is provided so as to be sandwiched between the pressing member 2221E and the bottom plate 2221Aa. The pressing member 2221E is formed in a plate shape, and a rod-shaped support portion 2221Ea protruding upward is formed on the surface opposite to the surface against which the elastic member 2221B abuts. The support portion 2221Ea is inserted into a guide recess 2221Aba formed in an upper plate 2221Ab of the drive casing 2221A, and is provided so as to be slidable inside the drive casing 2221A in the sliding direction of the actuating shaft 2222B, which is the direction in which the elastic member 2221B expands and contracts. The drive mechanism 2221 also has an actuating lever 2221C. The actuating lever 2221C is formed in a rod shape, and a base end 2221Ca is disposed inside the drive casing 2221A and is pivotally connected to the pressing member 2221E by a pin or the like, and its midpoint is pivotally supported by the drive casing 2221A at a fulcrum 2221Cc. A connecting member 2221D is pivotally supported at a tip 2221Cb of the actuating lever 2221C. An eyebolt to which the other end of the melt 1 is connected is fixed to the connecting member 2221D.

[0076] Inside the drive casing 2221A, the operating shaft 2222B is provided so that its tip, which extends in the opposite direction to the on-off valve 2021, penetrates the bottom plate 2221Aa of the drive casing 2221A to reach the inside of the drive casing 2221A and penetrates the elastic member 2221B in the expansion / contraction direction. In the drive mechanism 2221, a pressing member 2221E is connected to the tip of this operating shaft 2222B by screwing or the like. Therefore, the elastic force of the elastic member 2221B as it expands biases the operating lever 2221C via the pressing member 2221E in a direction (upward) that moves the base end 2221Ca away from the on-off valve 2021, and biases the operating shaft 2222B in a direction (upward) that moves away from the on-off valve 2021. On the other hand, when a load is applied so that the tip 2221Cb of the actuating lever 2221C, to which the other end of the melt 1 is connected, moves upward, the elastic member 2221B is compressed against the elastic force via the pressing member 2221E. In this case, the actuating shaft 2222B slides (downward) toward the on-off valve 2021, and the actuating lever 2221C swings (downward) in a direction in which the base end 2221Ca approaches the on-off valve 2021. Then, the actuating shaft 2222B moves in conjunction with the movement of the actuating lever 2221C, and the on-off valve 2021 is opened and closed up and down as shown by the arrow R in FIG. 7.

[0077] The operating lever 2221C has an eyebolt of a connecting member 2221D at its tip 2221Cb, to which the melt 1 is connected. One end of the melt 1 is fixed to a fixed portion 11 in the cavity chamber 102A so as to lift and support the tip 2221Cb of the operating lever 2221C upward during normal standby. When the tip 2221Cb of the operating lever 2221C is lifted upward, the operating shaft 2222B slides downward together with the support shaft 2212Aa against the elastic force of the elastic member 2221B, and the on-off valve 2021 is in a closed state. Therefore, if the molten mass 1 melts in the cavity chamber 102A due to the molten core material in the event of a severe accident, the elastic force of the elastic member 2221B will pull up the base end 2221Ca of the operating lever 2221C, the operating shaft 2222B, and the support shaft 2212Aa. When the support shaft 2212Aa is pulled up, the on-off valve 2021 opens, opening the cooling water pipe 51 and supplying cooling water to the cavity chamber 102A.

[0078] The auxiliary mechanism 2223 has an auxiliary casing 2223a joined to communicate with the upper end of the drive casing 2221A of the drive mechanism 2221. The auxiliary casing 2223a houses an actuating rod 2223b therein so that the actuating rod 2223b can move up and down. The actuating rod 2223b can penetrate into the drive casing 2221A through a guide recess 2221Aba in an upper plate 2221Ab of the drive casing 2221A and is provided so as to be able to abut against a support portion 2221Ea of the pressing member 2221E. The auxiliary casing 2223a is also provided with an operating handle 2223d that is rotated to move the actuating rod 2223b up and down. For example, when the operating handle 2223d is rotated, the actuating rod 2223b is moved up and down due to gear meshing. Therefore, when the operating handle 2223d of the auxiliary mechanism 2223 is rotated and the operating rod 2223b is moved downward, the operating rod 2223b comes into contact with the pressing member 2221E, causing the pressing member 2221E to move downward. Then, in the drive mechanism 2221, the elastic member 2221B is compressed by the pressing member 2221E, and the operating shaft 2222B of the opening mechanism 2222 slides downward together with the support shaft 2212Aa, causing the on-off valve 2021 to close. On the other hand, when the operating handle 2223d of the auxiliary mechanism 2223 is rotated and the operating rod 2223b is moved upward, the operating rod 2223b separates from the pressing member 2221E, allowing the pressing member 2221E to slide freely. Then, in the drive mechanism 2221, the elastic member 2221B extends due to the elastic force, and the operating shaft 2222B of the opening mechanism 2222 slides upward together with the support shaft 2212Aa, opening the on-off valve 2021. During maintenance of the water injection device 10, even when the other end of the molten mass 1 is detached, the auxiliary mechanism 2223 can move the operating shaft 2222B and the support shaft 2212Aa up and down by operating the operating handle 2223d to open and close the on-off valve 2021. That is, the auxiliary mechanism 2223 supports the elastic member 2221B in a compressed state against the elastic force of the elastic member 2221B so as to close the on-off valve 2021, while releasing the compression of the elastic member 2221B so as to open the on-off valve 1021.

[0079] Thus, the water injection device 10 of embodiment 3 includes a molten body 1 provided in a cavity chamber 102A below the reactor vessel 101 that receives the molten core material, and a valve mechanism 2002 that is provided in a separate chamber 102B separated from the cavity chamber 102A by a partition wall 102C but is connected to the molten body 1, is configured to be able to open and close a cooling water pipe 51 through which cooling water is sent to the cavity chamber 102A, and opens the cooling water pipe 51 when the molten body 1 melts.

[0080] According to the water injection device 10 of this embodiment 3, by providing the valve mechanism 2002 in a separate chamber 102B separated from the cavity chamber 102A by a partition wall 102C, it is possible to prevent the valve mechanism 2002 from being exposed to the molten core, prevent the operation of the valve mechanism 2002 from being hindered by the molten core, and operate the valve mechanism 2002 by the melting of the molten mass 1. As a result, the water injection device 10 of embodiment 3 can reliably inject cooling water into the cavity chamber 102A.

[0081] In addition, in the water injection device 10 of embodiment 3, the valve mechanism 2002 includes an on-off valve 2021 that opens and closes the cooling water pipe 51, and a valve opening section 2022 that is connected to the molten material 1 through the partition wall 102C and opens the on-off valve 2021 when the molten material 1 melts, and the valve opening section 2022 has an elastic member 2221B that generates an elastic force that puts the on-off valve 2021 in an open state, and the molten material 1 supports the elastic member 2221B in a compressed state against the elastic force of the elastic member 2221B so as to put the on-off valve 2021 in a closed state.

[0082] According to the water injection device 10 of the third embodiment, when the molten mass 1 is melted by the molten core material, the elastic member 2221B expands from the compressed state, and the on-off valve 2021 can be put into the open state.

[0083] In addition, in the water injection device 10 of embodiment 3, the valve mechanism 2002 supports the elastic member 2221B in a compressed state so as to place the on-off valve 2021 in a closed state, and further includes an auxiliary mechanism 2223 that releases the compressed state so as to place the on-off valve 2021 in an open state.

[0084] According to the water injection device 10 of the third embodiment, for example, when the molten mass 1 is connected or during maintenance, the on-off valve 2021 can be held in a closed state by the auxiliary mechanism 2223.

[0085] Furthermore, in the water injection device 10 of the third embodiment, the valve mechanism 2002 is housed inside the valve casing 2211, through which the valve body 2212A and the valve seat 2211C allow the cooling water to pass.

[0086] According to the water injection device 10 of the third embodiment, the valve body 2212A and the valve seat 2211C are protected by the valve casing 2211, so that the action and operation of the valve body 2212A and the valve seat 2211C can be always ensured.

[0087] In the water injection device 10 of the third embodiment, the valve mechanism 2002 has a valve element 2212A that is a gate valve.

[0088] According to the water injection device 10 of the third embodiment, a gate valve can be applied to the valve body 2212A.

[0089] Moreover, in the water injection device 10 of the third embodiment, the valve mechanism 2002 further includes a water blocking member 2213 provided between the valve body 2212A and the valve seat 2211C.

[0090] According to the water injection device 10 of this embodiment 3, the action and operation of the valve body 2212A and the valve seat 2211C can be always ensured by the water stop member 2213. The water injection device 10 of embodiment 3 is operated in the event of a severe accident, and since the on-off valve 2021 must be maintained in a closed state under normal circumstances and the on-off valve 2021 must be reliably opened in the event of a severe accident, it is necessary to always ensure the action and operation of the valve body 2212A and the valve seat 2211C.

[0091] The water injection device 10 of the third embodiment further includes an opening / closing mechanism 52 provided on the cooling water pipe 51 upstream of the valve mechanism 2002 .

[0092] According to the water injection device 10 of the third embodiment, the cooling water can be stopped by the opening and closing mechanism 52 when the valve mechanism 2002 is undergoing maintenance.

[0093] The present disclosure includes the following inventions. [Invention 1] a melt body provided in a cavity chamber below the reactor containment vessel for receiving the molten core; a valve mechanism that is provided in a separate chamber from the cavity chamber via a partition wall and is connected to the molten material, and that is configured to be able to open and close a cooling water pipe through which cooling water is sent to the cavity chamber, and that opens the cooling water pipe when the molten material is melted; 12. A water injection device comprising: [Invention 2] the valve mechanism includes an on-off valve that opens and closes the cooling water pipe, and a valve opening unit that is connected to the molten body through the partition wall and opens the on-off valve when the molten body is melted, the valve opening portion has a weight that generates a load that causes the on-off valve to be in an open state, the molten body lifts and supports the weight against the load of the weight so as to close the on-off valve; The water injection device according to invention 1. [Invention 3] The valve opening section includes a drive casing that supports the weight so that the weight can move up and down, and a viscous body that is accommodated inside the drive casing and below the weight. The water injection device according to invention 2. [Invention 4] the valve mechanism further includes an auxiliary mechanism that supports the on-off valve so that it is in a closed state and releases the support so that the on-off valve is in an open state. A water injection device according to invention 2 or 3. [Invention 5] The valve mechanism further includes levers fixed to both ends of an actuation shaft that supports opening and closing of the on-off valve and to which the weights are respectively attached, and a connecting member that connects the levers or the weights. The water injection device according to invention 2. [Invention 6] the valve mechanism includes an on-off valve that opens and closes the cooling water pipe, and a valve opening unit that is connected to the molten body through the partition wall and opens the on-off valve when the molten body is melted, the valve opening portion has an elastic member that generates an elastic force that opens the on-off valve, the molten material supports the elastic member in a compressed state against the elastic force of the elastic member so as to close the on-off valve. The water injection device according to invention 1. [Invention 7] the valve mechanism further includes an auxiliary mechanism that supports the elastic member in a compressed state so as to place the on-off valve in a closed state, and releases the compressed state so as to place the on-off valve in an open state. A water injection device according to invention 6. [Invention 8] The valve mechanism includes a valve body and a valve seat housed inside a valve casing that allows cooling water to pass through. A water injection device according to any one of inventions 1 to 7. [Invention 9] The valve mechanism has a valve element formed of a butterfly valve. A water injection device according to invention 8. [Invention 10] The valve mechanism includes a check valve as the valve element. A water injection device according to invention 8. [Invention 11] The valve mechanism is formed so that the opening diameter of the valve seat is smaller than the opening diameter of the inlet of the valve casing. A water injection device according to invention 10. [Invention 12] The valve mechanism includes a valve body formed of a gate valve. A water injection device according to invention 8. [Invention 13] The valve mechanism further includes a water-stopping member provided between the valve body and the valve seat. A water injection device according to any one of inventions 1 to 12. [Invention 14] an opening / closing mechanism provided on the cooling water pipe upstream of the valve mechanism, A water injection device according to any one of inventions 1 to 13. [Explanation of symbols]

[0094] 1. Melt 2 Valve mechanism 10 Water injection device 21 On-off valve 22 Valve opening 51 Cooling water pipe 52 Opening and closing mechanism 101 Reactor vessel 102A Cavity Room 102B Separate room 102C Bulkhead 211 Valve casing 211C Valve seat 212A Valve body 213 Water-stopping materials 221A Drive Casing 221B Weight 221C Viscous body 223 Auxiliary mechanism 1002 Valve mechanism 1021 On-off valve 1022 Valve opening section 1211 Valve casing 1211C Valve seat 1212A Valve body 1213 Water-stopping materials 1221B Weight 1222C Lever 1222D Connecting member 2002 Valve Mechanism 2021 On-off valve 2022 Valve opening section 2211 Valve casing 2211C Valve seat 2212A Valve body 2213 Water-stopping materials 2221B Elastic member 2223 Auxiliary mechanism

Claims

1. A molten body provided in a cavity chamber below a reactor containment vessel for receiving a molten core; a valve mechanism that is provided in a separate chamber from the cavity chamber via a partition wall and is connected to the molten material, and that is configured to be able to open and close a cooling water pipe through which cooling water is sent to the cavity chamber, and that opens the cooling water pipe when the molten material is melted; Including, the valve mechanism includes an on-off valve that opens and closes the cooling water pipe, and a valve opening unit that is connected to the molten body through the partition wall and opens the on-off valve when the molten body is melted, the valve opening section has a weight that generates a load that puts the on-off valve into an open state, and includes a drive casing that supports the weight so that the weight can move up and down, and a viscous body that is accommodated inside the drive casing and below the weight, the molten body lifts and supports the weight against the load of the weight so as to close the on-off valve; Water injection device.

2. A molten body provided in a cavity chamber below the reactor containment vessel for receiving molten core material; a valve mechanism that is provided in a separate chamber from the cavity chamber via a partition wall and is connected to the molten material, and that is configured to be able to open and close a cooling water pipe through which cooling water is sent to the cavity chamber, and that opens the cooling water pipe when the molten material is melted; Including, the valve mechanism includes an on-off valve that opens and closes the cooling water pipe, and a valve opening unit that is connected to the molten body through the partition wall and opens the on-off valve when the molten body is melted, the valve opening portion has a weight that generates a load that causes the on-off valve to be in an open state, the molten body lifts and supports the weight against the load of the weight so as to close the on-off valve; The valve mechanism further includes levers fixed to both ends of an actuation shaft that supports opening and closing of the on-off valve and to which the weights are respectively attached, and a connecting member that connects the levers or the weights. Water injection device.

3. the valve mechanism further includes an auxiliary mechanism that supports the on-off valve so that it is in a closed state and releases the support so that the on-off valve is in an open state. The water injection device according to claim 1 or 2.

4. A melt body provided in a cavity chamber below the reactor containment vessel for receiving the melt core; a valve mechanism that is provided in a separate chamber from the cavity chamber via a partition wall and is connected to the molten material, and that is configured to be able to open and close a cooling water pipe through which cooling water is sent to the cavity chamber, and that opens the cooling water pipe when the molten material is melted; Including, the valve mechanism includes an on-off valve that opens and closes the cooling water pipe, and a valve opening unit that is connected to the molten body through the partition wall and opens the on-off valve when the molten body is melted, the valve opening portion has an elastic member that generates an elastic force that opens the on-off valve, the molten material is provided in a manner to support the elastic member in a compressed state against the elastic force of the elastic member so as to close the on-off valve, the valve mechanism further includes an auxiliary mechanism that supports the elastic member in a compressed state so as to close the on-off valve regardless of support by the molten material, and releases the compressed state so as to open the on-off valve. Water injection device.

5. The valve mechanism includes a valve body and a valve seat housed inside a valve casing that allows cooling water to pass through. The water injection device according to claim 1 or 2.

6. The valve mechanism has a valve element formed of a butterfly valve. The water injection device according to claim 5.

7. The valve mechanism includes a check valve as the valve element. The water injection device according to claim 5.

8. The valve mechanism is formed so that the opening diameter of the valve seat is smaller than the opening diameter of the inlet of the valve casing. The water injection device according to claim 7.

9. The valve mechanism includes a valve body formed of a gate valve. The water injection device according to claim 5.

10. The valve mechanism further includes a water-stopping member provided between the valve body and the valve seat.

5. The water injection device according to claim 1, 2 or 4.

11. an opening / closing mechanism provided on the cooling water pipe upstream of the valve mechanism, 5. The water injection device according to claim 1, 2 or 4.

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