JP2019138886A - Sealing jig, method for operating sealing jig, and method for attaching sealing jig - Google Patents

Abstract

To easily and surely seal the region between the end part of a conduit tube and a simple tube.SOLUTION: The present invention includes: an elastic member 1 having seal parts (first seal part 1B, second seal part 1C, and a third seal part 1D) arranged in at least three positions between the conduit tube 148 side and the simple tube 151; a casing 2 over the elastic member 1; and a pressing unit 3 for applying a pressing force to each seal part of the elastic member 1 through the casing 2.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a structure in which a thimble tube as a guide tube of an in-core measurement device installed in a lower part of a reactor is inserted into a conduit tube as an outer tube thereof, and the end of the conduit tube and a thimble The present invention relates to a sealing jig, a sealing jig operating method, and a sealing jig mounting method for performing sealing with a tube.

  In a nuclear power plant (Pressurized Water Reactor (PWR)), the reactor vessel is provided with a number of instrumentation nozzles that penetrate the lower mirror, and each instrumentation nozzle is located inside the reactor. An in-furnace instrumentation guide tube is connected to the upper end portion, while a conduit tube is connected to the lower end portion outside the furnace. A thimble tube into which a neutron flux detector capable of measuring a neutron flux is inserted is inserted into the conduit tube. The thimble tube can be inserted into the fuel assembly through the conduit tube and the in-core instrumentation guide tube via the conduit tube. On the other hand, the conduit tube is drawn out of the reactor vessel from the lower mirror, and its end is fixed to a seal table separate from the reactor vessel. The conduit tube and the thimble tube inserted through the conduit tube are sealed at the end of the conduit tube so as to prevent water leakage by a high pressure seal (for example, a pressure resistance of 15 MPa or more).

  In the nuclear power plant described above, when the fuel assembly is removed from the reactor vessel during the periodic inspection, the neutron detector and the thimble tube are obstructive when the fuel assembly is removed and installed, so the thimble tube is removed from the fuel assembly. It will be. Therefore, after extracting the neutron detector from the thimble tube, at least several meters of the thimble tube extracted from the fuel assembly is extracted from the end of the conduit tube. In such a case, a low-pressure seal (for example, for the purpose of preventing water leakage due to water head pressure of water filling in the cavity of the reactor vessel between the end of the conduit tube and the middle part of the thimble tube that has been pulled out. , Withstand pressure of about 1 MPa).

  By the way, for example, Patent Literature 1 discloses a seal packing in which the inner wall surface of the packing box of the cylinder cover of the hydraulic cylinder and the outer peripheral surface of the cylinder rod are used as seal surfaces.

Japanese Utility Model Publication No.59-155360

  When system decontamination is performed in the decommissioning plan of a nuclear power plant, it is necessary to set the internal pressure of the reactor cooling system (RCS: Reactor Coolant System) to an intermediate pressure (for example, about 2.75 MPa). However, the above-described low pressure seal cannot withstand the above intermediate pressure of the reactor cooling system. Further, since the fuel assembly is not loaded at the time of system decontamination, use of the above-described high-pressure seal requires modification (cutting, welding, etc.) of the middle part where the thimble tube is pulled out, and the work cost increases. It will be.

  This invention solves the subject mentioned above, and provides the sealing jig which can perform the sealing between the edge part of a conduit tube and a thimble tube easily and reliably, a sealing jig operating method, and a sealing jig attachment method. For the purpose.

  In order to achieve the above object, a sealing jig according to an aspect of the present invention is a seal that performs a seal between an end of a conduit tube provided in a reactor vessel and a thimble tube inserted into the conduit tube. An elastic member having a seal portion disposed at least in three places between the conduit tube side and the thimble tube side, a casing covering the elastic member, and the elastic member via the casing. A pressing portion that applies a pressing force to each of the sealing portions.

  Further, in the first sealing jig according to one aspect of the present invention, the first sealing jig has an inner peripheral surface provided at an end of the conduit tube and facing the outer peripheral surface of the thimble tube with a gap therebetween, and the shaft of the conduit tube. A seal seat having an end surface facing in the direction and having an annular recess formed around the axis of the conduit tube at the end surface, and the elastic member is formed in an annular shape so as to surround the outer periphery of the thimble tube, and The thimble tube is formed with a notch that can be inserted from the radial direction so that the thimble tube can be inserted into the thimble tube. A first seal portion, a second seal portion in contact with the end surface, and a third seal portion inserted into the annular recess, and the casing includes the elastic member and An inner casing that is formed so as to surround the end face of the seal seat and is divided into two so as to be radially arranged on the thimble tube, and is formed along the outer shape of the inner casing, and is formed on the thimble tube and the inner casing. And an outer casing having a notch groove that is open so as to be arranged from the radial direction, and the pressing portion is configured to press the casing in the axial direction toward the seal seat. desirable.

  In the second sealing jig according to an aspect of the present invention, the elastic member has a notch that is formed so as to surround an outer periphery of the thimble tube and that is open to the thimble tube so that the thimble tube can be inserted from a radial direction. A first seal portion formed so as to surround the outer periphery of the conduit tube, and a second seal portion formed so as to have a notch that can be inserted into the conduit tube from the radial direction. A pair of third seal portions that connect the first seal portion and the second seal portion, and the casing includes an end portion of the conduit tube and includes outer peripheries of the conduit tube and a part of the thimble tube. The conduit tube and the thimble tube are formed so as to surround and are divided in two so as to be arranged from the radial direction of the conduit tube and the thimble tube. A housing groove for housing the first seal portion, the second seal portion, and the third seal portion on the facing surface of the casing, and the pressing portion causes the facing surface divided into two parts of the casing to approach. It is desirable to be configured to press.

  In order to achieve the above-described object, a sealing jig operating method according to an aspect of the present invention provides a difference in the shape of the end of the conduit tube when performing sealing between the end of the conduit tube and the thimble tube. According to the above, the first seal jig and the second seal jig are selected and used, while the second seal jig is used in common.

  In order to achieve the above-described object, a sealing jig attachment method according to an aspect of the present invention is a sealing jig that uses a first sealing jig when performing sealing between an end of the conduit tube and the thimble tube. In the mounting method, the elastic member is inserted from the radial direction of the thimble tube through the notch, and the two split positions of the inner casing are removed from the notch position of the elastic member. An inner casing is arranged in the thimble tube in the radial direction, and the outer casing is radially arranged in the thimble tube and the inner casing so as to remove the position of the cutout groove in the outer casing from the two-divided position of the inner casing. And the casing is pressed toward the seal seat in the axial direction by the pressing portion.

  In order to achieve the above-described object, a sealing jig attachment method according to an aspect of the present invention is a sealing jig that uses a second sealing jig to perform sealing between an end of the conduit tube and the thimble tube. In the mounting method, the first seal portion of the elastic member is inserted from the radial direction of the thimble tube through the notch, and the second seal portion is inserted into the diameter of the conduit tube through the notch. The casing is inserted from the direction, and the casing is removed from the position of the notch of the first seal part and the position of the notch of the second seal part so that the two-divided position of the casing is removed. It arrange | positions from the radial direction of a tube, and it presses so that the opposing surface divided into 2 by the said casing may be made to contact.

  According to the present invention, when system decontamination is performed, even if the internal pressure of a reactor cooling system (RCS: Reactor Coolant System) is set to an intermediate pressure (for example, about 2.75 MPa), the intermediate pressure can be withstood. Each seal portion can prevent water leakage between the end of the conduit tube and the thimble tube. As a result, the seal between the end of the conduit tube and the thimble tube can be easily and reliably performed.

FIG. 1 is a schematic configuration diagram of an example of a nuclear power plant. FIG. 2 is a longitudinal sectional view of a pressurized water reactor. FIG. 3 is a schematic side view illustrating the conduit tube. FIG. 4 is a side view of the conduit tube and the thimble tube. FIG. 5 is a longitudinal sectional view of the conduit tube and the thimble tube. FIG. 6 is a side view of the conduit tube and the thimble tube. FIG. 7 is a longitudinal sectional view of a sealing jig according to the embodiment of the present invention. FIG. 8 is a front view of the sealing jig according to the embodiment of the present invention. FIG. 9 is a perspective view showing a part of the sealing jig according to the embodiment of the present invention. FIG. 10 is a longitudinal sectional view of another example of the sealing jig according to the embodiment of the present invention. FIG. 11 is a plan view showing a part of another example of the sealing jig according to the embodiment of the present invention. FIG. 12 is a side view showing a part of another example of the sealing jig according to the embodiment of the present invention. FIG. 13 is a plan view showing a part of another example of the sealing jig according to the embodiment of the present invention. FIG. 14 is a side view showing a part of another example of the sealing jig according to the embodiment of the present invention.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

  FIG. 1 is a schematic configuration diagram of an example of a nuclear power plant, and FIG. 2 is a longitudinal sectional view of a pressurized water reactor.

  The nuclear power plant shown in FIG. 1 has a pressurized water reactor (PWR: Pressurized Water Reactor). In this nuclear power plant, in a reactor containment vessel 100, a reactor vessel 101 of a pressurized water reactor, a pressurizer 102, a steam generator 103 and a primary cooling water pump 104 are sequentially connected by a primary cooling water pipe 105, A circulation path of primary cooling water is configured.

  The reactor vessel 101 stores the fuel assembly 120 in a sealed state. The reactor vessel 101 includes a reactor vessel main body 101a and a reactor vessel lid 101b mounted on the upper portion thereof so that the fuel assembly 120 can be inserted and removed. It is configured. The reactor vessel main body 101a is provided with an inlet-side nozzle 101c and an outlet-side nozzle 101d for supplying and discharging light water as primary cooling water in the upper part. A primary cooling water pipe 105 is connected to the outlet side nozzle 101 d so as to communicate with the inlet side water chamber 103 a of the steam generator 103. The inlet side nozzle 101c is connected to the primary cooling water pipe 105 so as to communicate with the outlet side water chamber 103b of the steam generator 103.

  The steam generator 103 is provided with an inlet-side water chamber 103a and an outlet-side water chamber 103b partitioned by a partition plate 103c in a lower part formed in a hemispherical shape. The inlet side water chamber 103a and the outlet side water chamber 103b are separated from the upper side of the steam generator 103 by a tube plate 103d provided on the ceiling portion. On the upper side of the steam generator 103, an inverted U-shaped heat transfer tube 103e is provided. The end portion of the heat transfer tube 103e is supported by the tube plate 103d so as to connect the inlet side water chamber 103a and the outlet side water chamber 103b. The inlet-side water chamber 103a is connected to the inlet-side primary cooling water pipe 105, and the outlet-side water chamber 103b is connected to the outlet-side primary cooling water pipe 105. In addition, the steam generator 103 is connected to the upper side upper end partitioned by the tube plate 103d, the outlet side secondary cooling water pipe 106a, and the upper side part is connected to the inlet side secondary cooling water pipe 106b. Has been.

  Further, in the nuclear power plant, the steam generator 103 is connected to the steam turbine 107 via the secondary cooling water pipes 106a and 106b outside the reactor containment vessel 100, and the circulation path of the secondary cooling water is configured. .

  The steam turbine 107 includes a high-pressure turbine 108 and a low-pressure turbine 109, and a generator 110 is connected to the steam turbine 107. In addition, the high-pressure turbine 108 and the low-pressure turbine 109 are connected to a moisture separation heater 111 that is branched from the secondary cooling water pipe 106a. The low pressure turbine 109 is connected to the condenser 112. The condenser 112 is connected to the secondary cooling water pipe 106b. The secondary cooling water pipe 106b is connected to the steam generator 103 as described above, and reaches from the condenser 112 to the steam generator 103, and the condensate pump 113, the low-pressure feed water heater 114, the deaerator 115, and the main feed water pump. 116, and a high-pressure feed water heater 117 are provided.

  Therefore, in the nuclear power plant, the primary cooling water is heated in the reactor vessel 101 to become a high temperature and high pressure, and is pressurized by the pressurizer 102 to keep the pressure constant, and the steam is passed through the primary cooling water pipe 105. It is supplied to the generator 103. In the steam generator 103, heat exchange between the primary cooling water and the secondary cooling water is performed, whereby the secondary cooling water evaporates and becomes steam. The cooled primary cooling water after heat exchange is recovered to the primary cooling water pump 104 side via the primary cooling water pipe 105 and returned to the reactor vessel 101. On the other hand, the secondary cooling water converted into steam by heat exchange is supplied to the steam turbine 107. In connection with the steam turbine 107, the moisture separator / heater 111 removes moisture from the exhaust from the high-pressure turbine 108, further heats it to an overheated state, and then sends it to the low-pressure turbine 109. The steam turbine 107 is driven by the steam of the secondary cooling water, and the power is transmitted to the generator 110 to generate power. Steam used for driving the turbine is discharged to the condenser 112. The condenser 112 exchanges heat between the cooling water (for example, seawater) taken by the pump 112b through the intake pipe 112a and the steam discharged from the low-pressure turbine 109, and condenses the steam to produce a low-pressure saturated liquid. Return to. The cooling water used for heat exchange is discharged from the drain pipe 112c. Further, the condensed saturated liquid becomes secondary cooling water, and is sent out of the condenser 112 by the condensate pump 113 through the secondary cooling water pipe 106b. Further, the secondary cooling water passing through the secondary cooling water pipe 106b is heated by the low-pressure feed water heater 114, for example, by the low-pressure steam extracted from the low-pressure turbine 109, and dissolved oxygen and non-condensed gas (ammonia gas) in the deaerator 115. After the impurities such as) are removed, the water is fed by the main feed pump 116 and heated by the high-pressure steam extracted from the high-pressure turbine 108 by the high-pressure feed water heater 117 and then returned to the steam generator 103.

  In the pressurized water reactor of the nuclear power plant configured as described above, as shown in FIG. 2, the reactor vessel 101 has a nuclear reactor in which a reactor internal structure including the fuel assembly 120 can be inserted. A reactor vessel lid 101b is fixed to the vessel body 101a by a plurality of stud bolts 121 and nuts 122 so as to be opened and closed.

  The reactor vessel main body 101a has a cylindrical shape in which the upper portion can be opened by removing the reactor vessel lid 101b and the lower portion is closed by a lower mirror 101e having a hemispherical shape. In the reactor vessel main body 101a, the upper core support plate 123 is fixed above the inlet side nozzle 101c and the outlet side nozzle 101d, while the lower core support is located near the lower mirror 101e. The plate 124 is fixed. The upper core support plate 123 and the lower core support plate 124 have a disc shape and are formed with a number of communication holes (not shown). The upper core support plate 123 is connected to an upper core plate 126 having a plurality of communication holes (not shown) formed below through a plurality of core support rods 125.

  In the reactor vessel main body 101a, a cylindrical reactor core 127 having a cylindrical shape is disposed with a predetermined gap from an inner wall surface. The reactor tank 127 is connected to an upper core plate 126 at an upper portion and a disk shape at a lower portion. The lower core plate 128 in which a large number of communication holes (not shown) are formed is connected. The lower core plate 128 is supported by the lower core support plate 124. That is, the core tank 127 is supported by the lower core support plate 124 of the reactor vessel main body 101a.

  A core 129 is formed by the upper core plate 126, the core tank 127, and the lower core plate 128. A large number of fuel assemblies 120 are disposed inside the core 129. Although not shown, the fuel assembly 120 is configured by bundling a large number of fuel rods in a lattice pattern with a support lattice, and an upper nozzle is fixed to the upper end portion and a lower nozzle is fixed to the lower end portion. The core 129 has a large number of control rods 130 disposed therein. The large number of control rods 130 are combined at the upper end portion into a control rod cluster 131 that can be inserted into the fuel assembly 120. A number of control rod cluster guide tubes 132 are fixed to the upper core support plate 123 so as to pass through the upper core support plate 123, and the lower end portion of each control rod cluster guide tube 132 is controlled in the fuel assembly 120. It extends to the bar cluster 131.

  A reactor vessel lid 101b constituting the reactor vessel 101 has a hemispherical upper portion and is provided with a control rod drive device 133 of a magnetic jack, and is housed in a housing 134 that is integrated with the reactor vessel lid 101b. Has been. The control rod cluster guide tube 132 has an upper end extending to the control rod drive device 133, and the control rod cluster drive shaft 135 extends from the control rod drive device 133. The control rod cluster 131 can be gripped by extending to the fuel assembly 120.

  The control rod drive device 133 extends in the vertical direction and is connected to the control rod cluster 131, and a control rod cluster drive shaft 135 having a plurality of circumferential grooves arranged on the surface thereof at equal pitches in the longitudinal direction. The power of the reactor is controlled by moving up and down with a magnetic jack.

  The reactor vessel body 101a is provided with a number of instrumentation nozzles 146 that penetrate the lower mirror 101e, and each instrumentation nozzle 146 has an in-reactor instrumentation guide tube 147 connected to the upper end of the inside of the reactor. On the other hand, a conduit tube 148 is connected to a lower end portion outside the furnace. Each in-core instrumentation guide tube 147 has an upper end connected to the lower core support plate 124, and upper and lower connecting plates 149, 150 for suppressing vibration are attached. The conduit tube 148 is provided to reach the lower core plate 128, and a thimble tube 151 into which a neutron flux detector (not shown) capable of measuring a neutron flux is inserted is inserted. The thimble tube 151 can be inserted into the fuel assembly 120 through the lower core plate 128 through the instrumentation nozzle 146 and the in-core instrumentation guide tube 147 via the conduit tube 148.

  Such a pressurized water reactor controls the nuclear fission in the core 129 by moving the control rod cluster drive shaft 135 by the control rod drive device 133 and extracting the control rod 130 from the fuel assembly 120 by a predetermined amount. The light water filled in the reactor vessel 101 is heated by the generated thermal energy, and high-temperature light water is discharged from the outlet side nozzle 101d. That is, the nuclear fuel constituting the fuel assembly 120 is fissioned to release neutrons, and the light water as the moderator and the primary cooling water reduces the kinetic energy of the released fast neutrons to become thermal neutrons. It makes it easy to cause nuclear fission and takes away the generated heat to cool it. On the other hand, by inserting the control rod 130 into the fuel assembly 120, the number of neutrons generated in the core 129 is adjusted, and by inserting all the control rod 130 into the fuel assembly 120, the nuclear reactor is emergency Can be stopped. In the reactor vessel 101, an upper plenum 152 communicating with the outlet side nozzle 101d is formed above the core 129, and a lower plenum 153 is formed below. A downcomer portion 154 that communicates with the inlet side nozzle 101 c and the lower plenum 153 is formed between the reactor vessel 101 and the reactor core 127. Accordingly, light water flows into the reactor vessel body 101a from the inlet side nozzle 101c, flows down the downcomer portion 154, reaches the lower plenum 153, and is guided upward by the spherical inner surface of the lower plenum 153. And then flows into the core 129 after passing through the lower core support plate 124 and the lower core plate 128. The light water that has flowed into the core 129 absorbs heat energy generated from the fuel assemblies 120 that constitute the core 129, thereby cooling the fuel assemblies 120 while passing through the upper core plate 126 at a high temperature. Then, it rises to the upper plenum 152 and is discharged through the outlet side nozzle 101d. The light water discharged from the reactor vessel 101 is sent to the steam generator 103 as described above.

  FIG. 3 is a schematic side view illustrating the conduit tube. FIG. 4 is a side view of the conduit tube and the thimble tube. FIG. 5 is a longitudinal sectional view of the conduit tube and the thimble tube. FIG. 6 is a side view of the conduit tube and the thimble tube.

  As described above with reference to FIG. 2, the thimble tube 151 is inserted into the conduit tube 148. The conduit tube 148 extends to the outside of the instrumentation nozzle 146. As shown in FIG. 3, the reactor vessel 101 is supported by being suspended in the reactor containment vessel 100. The reactor containment vessel 100 has a piping chamber 155 formed below the reactor vessel 101. The plurality of conduit tubes 148 are drawn out of the reactor vessel 101 from the lower mirror 101e, and are bent around the piping chamber 155 and then fixed to a seal table 156 in a separate chamber. The thimble tube 151 is inserted from the end of the fixed conduit tube 148. A neutron flux detector is inserted into the thimble tube 151.

  As shown in FIG. 4, the seal table 156 is formed in a plate shape, and is fixed in a state where the end portion of the conduit tube 148 penetrates from the bottom to the top. The plurality of conduit tubes 148 are arranged at regular intervals and are erected from the upper surface of the seal table 156.

  As described above, the thimble tube 151 is inserted into the conduit tube 148. As shown in FIGS. 4 and 5, the conduit tube 148 is provided with a seal seat 148A at the end thereof. The seal seat 148A extends downward in the axial direction (vertical direction) in which the central axis S of the conduit tube 148 extends, has a cylindrical shape so as to pass through the end of the conduit tube 148, and has an external thread on the outer peripheral surface. It has a ferrule 148Aa formed with a portion. An annular ferrule 148Ab is fitted to the ferrule 148Aa, and the outer periphery of the ferrule 148Aa is fixed so that the seal seat 148A is sealed and fixed to the end of the conduit tube 148 by maintaining the fitting of the ferrules 148Aa and 148Ab. A nut 148Ac is screwed into the male screw portion of the surface. Further, the seal seat 148A has a flange portion 148Ad formed at the upper portion in the axial direction. The flange portion 148Ad has an end surface 148Ae facing upward, and an annular recess 148Af surrounding the central axis S is formed on the end surface 148Ae. The O-ring 148B is disposed in the annular recess 148Af. The seal seat 148A is provided so as to penetrate in the axial direction so that the thimble tube 151 is inserted, and an inner peripheral surface 148Ag facing the outer peripheral surface of the thimble tube 151 with a gap is formed on the flange portion 148Ad side. ing.

  The thimble tube 151 inserted through the conduit tube 148 is provided with a seal seat 151A in the middle thereof. The seal seat 151 </ b> A extends upward in the axial direction (vertical direction) in which the central axis S of the conduit tube 148 extends, has a cylindrical shape so as to pass through the thimble tube 151, and a male screw portion is formed on the outer peripheral surface. The ferrule 151Aa is provided. An annular ferrule 151Ab is fitted to the ferrule 151Aa, and the male seat on the outer peripheral surface of the ferrule 151Aa is fixed so that the seal seat 151A is sealed and fixed to the thimble tube 151 by maintaining the fitting of the ferrules 151Aa and 151Ab. A nut 151Ac is screwed into the thread portion. The seal seat 151A has a flange portion 151Ad formed in the lower portion in the axial direction. The flange portion 151Ad has an end surface 151Ae facing downward and facing the annular recess 148Af. The flange portion 151Ad is in contact with the inner peripheral surface 148Ag of the seal seat 148A at the center of the end surface 151Ae and the outer peripheral surface of the inner peripheral surface 148Ag and the thimble tube 151. A cylindrical portion 151Af to be inserted into the gap with the surface is formed.

  Each of the seal seats 148A and 151A has a high-pressure seal maintained in a state in which the end surfaces 148Ae and 151Ae of the flange portions 148Ad and 151Ad are in contact with each other by fixing the flange portions 148Ad and 151Ad by the clamp portion 151B. The high pressure seal is configured to prevent leakage between the end of the conduit tube 148 and the thimble tube 151. A neutron detector (shown by a one-dot chain line in FIG. 4) is inserted into the thimble tube 151 while being sealed by the high-pressure seal.

  In such a configuration, when the fuel assembly 120 is removed from the reactor vessel 101 during the periodic inspection, the neutron detector and the thimble tube 151 interfere with the removal and installation of the fuel assembly 120. The tube 151 is extracted from the fuel assembly 120. The neutron detector is provided at the tip of a detector tube (not shown), and the detector tube is wound up by a winder (not shown) provided in the upper part of a separate chamber in which the seal table 156 is disposed. It is extracted from the thimble tube 151. Thereafter, the thimble tube 151 is withdrawn from the end of the conduit tube 148 in a separate chamber at least a few meters from the fuel assembly 120. Specifically, as shown in FIG. 6, the clamp portion 151B is removed, and the thimble tube 151 is pulled out in the axial direction (in the direction of the arrow in FIG. 6) so that the end faces 148Ae and 151Ae of the flanges 148Ad and 151Ad are separated. . At the time of periodic inspection, water is filled in the cavity of the reactor vessel 101. Therefore, the end portion of the conduit tube 148 and the middle portion where the thimble tube 151 is pulled out for the purpose of preventing water leakage due to the water head pressure. Is provided with a low pressure seal (for example, withstand pressure of about 1 MPa). Although the low-pressure seal is not clearly shown in the drawing, a cylindrical seal member is inserted into a gap between the inner peripheral surface 148Ag of the seal seat 148A and the outer peripheral surface of the thimble tube 151, and a casing and a casing surrounding the seal member are interposed therebetween. A pressing portion that presses the seal member into the gap is provided.

  FIG. 7 is a longitudinal sectional view of the sealing jig according to the present embodiment. FIG. 8 is a front view of the sealing jig according to the present embodiment. FIG. 9 is a perspective view showing a part of the sealing jig according to the present embodiment.

  When performing system decontamination, the sealing jig of the present embodiment needs to make the internal pressure of a reactor cooling system (RCS: Reactor Coolant System) an intermediate pressure (for example, about 2.75 MPa), and withstand this intermediate pressure. Thus, water leakage between the end of the conduit tube 148 and the thimble tube 151 is prevented.

  The sealing jig of this embodiment includes an elastic member 1, a casing 2, and a pressing portion 3.

  As shown in FIGS. 7 to 9, the elastic member 1 is formed in an annular shape with a center passing through the outer periphery of the thimble tube 151, and the central axis S of the thimble tube 151 (conduit tube 148) extends. In the axial direction (vertical direction), it has an upper surface 1a and a lower surface 1b facing in the axial direction, and an inner peripheral surface 1c and an outer peripheral surface 1d facing in the radial direction, respectively. The elastic member 1 has a cut 1A, a first seal portion 1B, a second seal portion 1C, and a third seal portion 1D.

  As shown in FIG. 9, the cut 1A is provided by cutting the upper surface 1a, the lower surface 1b, the inner peripheral surface 1c, and the outer peripheral surface 1d so as to open the ring at one place, and the elastic member 1 is a thimble tube. It opens to 151 from the radial direction (direction crossing (orthogonal) the axial direction).

  As shown in FIGS. 7 to 9, the first seal portion 1 </ b> B is a portion provided in a cylindrical shape so as to protrude downward from the lower surface 1 b integrally with the elastic member 1 in the center through which the elastic member 1 passes. The first seal portion 1B has a cylindrical inner peripheral surface 1Ba continuous to the inner peripheral surface 1c of the elastic member 1 and a cylindrical outer peripheral surface 1Bb. The first seal portion 1B has an inner peripheral surface 1Ba that can contact the inner peripheral surface of the thimble tube 151, and an outer peripheral surface 1Bb that can contact the inner peripheral surface 148Ag of the seal seat 148A. The inner peripheral surface of the seal seat 148A and the inner peripheral surface 148Ag of the seal seat 148A are inserted into a gap.

  The second seal portion 1C is the lower surface 1b of the elastic member 1, and is a portion that comes into contact with the end surface 148Ae of the seal seat 148A.

  The third seal portion 1D is a portion provided in a cylindrical shape integrally with the elastic member 1 and projecting downward from the lower surface 1b on the radially outer side (side away from the central axis S) of the first seal portion 1B. The third seal portion 1D is formed so as to be inserted into the annular recess 148Af of the seal seat 148A.

  That is, the elastic member 1 has seal portions 1B, 1C, and 1D disposed at least at three locations between the conduit tube 148 side and the thimble tube 151 side.

  As shown in FIGS. 7 and 8, the casing 2 includes an inner casing 2 </ b> A and an outer casing 2 </ b> B.

  The inner casing 2A has a cylindrical portion 2Aa so as to surround the elastic member 1 and the end surface 148Ae of the seal seat 148A, and a closing portion 2Ab that closes one (upper) in the axial direction (vertical direction) of the cylindrical portion 2Aa. A through hole 2Ac is formed through the thimble tube 151 in the closing portion 2Ab. In addition, the inner casing 2A is formed with a flange portion 2Ad protruding in the radial direction on the other side (downward) of the axial direction (vertical direction) that is the opening side of the cylindrical portion 2Aa. In the inner casing 2A, the cylindrical portion 2Aa, the blocking portion 2Ab, the through hole 2Ac, and the flange portion 2Ad are divided into two parts so that the inner casing 2A can be disposed in the thimble tube 151 from the radial direction.

  The outer casing 2B covers the inner casing 2A along the outer shape of the inner casing 2A, and a closing portion 2Bb that closes one side (upper direction) in the axial direction (vertical direction) of the cylindrical portion 2Ba. A through hole 2Bc is formed through the thimble tube 151 in the closing portion 2Bb. The outer casing 2B has a notch groove 2Bd in which one side of the cylindrical portion 2Ba, the blocking portion 2Bb, and the through hole 2Bc is opened so as to be disposed in the thimble tube 151 and the inner casing 2A from the radial direction. . The outer casing 2B is formed with a protruding portion 2Be that protrudes in a circular shape so as to surround the through hole 2Bc at the center of the upper surface of the closing portion 2Bb. The outer casing 2B covers the outer side of the inner casing 2A, and the lower end in the axial direction (vertical direction) that is the opening side of the cylindrical portion 2Ba abuts on the flange portion 2Ad of the inner casing 2A.

  That is, the casing 2 covers the elastic member 1.

  As shown in FIGS. 7 and 8, the pressing portion 3 includes a pressing member 3 </ b> A and a support portion 3 </ b> B.

  The pressing member 3A extends in the axial direction (vertical direction) in which the central axis S of the thimble tube 151 (conduit tube 148) extends, and has a through hole 3Aa formed in the center so as to be inserted through the thimble tube 151. It is formed in a column shape. The pressing member 3A has a male screw portion 3Ab formed on the outer periphery. Moreover, nut 3Ac is integrally formed in the upper end of 3 A of press members. In addition, the pressing member 3A is integrally formed with a fitting portion 3Ad that fits into the protruding portion 2Be of the outer casing 2B at the lower end thereof. The pressing member 3A includes a through hole 3Aa, a male screw portion 3Ab, a nut 3Ac, and a notch groove 3Ae in which one side of the fitting portion 3Ad is opened so that the pressing member 3A can be arranged in the thimble tube 151 from the radial direction. Yes.

  The support portion 3B has a support portion main body 3Ba formed so as to extend along the axial direction (vertical direction) at the side portion of the thimble tube 151 (conduit tube 148). The support portion main body 3Ba has an upper end formed with a female screw portion 3Bb that is screwed into the male screw portion 3Ab of the pressing member 3A. The female screw portion 3Bb is provided to extend in the radial direction of the thimble tube 151 (conduit tube 148) from the upper end of the support portion main body 3Ba. In addition, the support body 3Ba has a fixed portion 3Bc fixed to the conduit tube 148 at the lower end thereof. The fixing portion 3Bc is provided to extend from the lower end of the support portion main body 3Ba in the radial direction of the thimble tube 151 (conduit tube 148). The fixing portion 3Bc includes a fitting recess 3Bca that is fitted to the side portion of the conduit tube 148, and a fixture that is attached to the fitting recess 3Bca with a screw 3Bcc and is secured to the side portion of the conduit tube 148 together with the fitting recess 3Bca. 3Bcb. The support portion 3B has a fixing nut 3Bd that is screwed into the male screw portion 3Ab of the pressing member 3A. The fixing nut 3Bd is screwed into the male screw portion 3Ab of the pressing member 3A above the female screw portion 3Bb. The support portion 3B has a female thread portion 3Bb at the upper end of the support portion main body 3Ba and a notch groove 3Be in which one side of the fixing nut 3Bd is opened so that the support portion 3B can be arranged in the thimble tube 151 from the radial direction.

  That is, in the upper end of the support portion main body 3Ba, the pressing portion 3 is in a state where the male screw portion 3Ab of the pressing member 3A is screwed into the female screw portion 3Bb and the fixing nut 3Bd is screwed into the male screw portion 3Ab. The pressing member 3A, the female screw portion 3Bb, and the fixing nut 3Bd are disposed on the conduit tube 148 from the radial direction. Further, the pressing portion 3 is fitted at the lower end of the support portion main body 3Ba so that the support portion main body 3Ba of the support portion 3B extends in the axial direction at the side portions of the conduit tube 148 and the thimble tube 151. Recess 3Bca and fixture 3Bcb are attached with screws 3Bcc and secured to the side of conduit tube 148. After that, the male screw portion 3Ab is tightened with the nut 3Ac via the female screw portion 3Bb, the fitting portion 3Ad is fitted to the protruding portion 2Be of the outer casing 2B, and the outer casing 2B is pressed downward together with the inner casing 2A. Then, a pressing force is applied to press the elastic member 1 against the seal seat 148A.

  The sealing jig of the present embodiment configured as described above inserts the elastic member 1 from the radial direction of the thimble tube 151 through the cut 1A. Next, the inner casing 2A is disposed on the thimble tube 151 from the radial direction so that the position of the inner casing 2A divided into two parts is removed from the position of the cut 1A of the elastic member 1. Next, the outer casing 2B is inserted into the thimble tube 151 and the inner casing 2A from the radial direction so as to remove the position of the notch groove 2Bd of the outer casing 2B from the two-divided position of the inner casing 2A. Next, the casing 2 is pressed in the axial direction toward the seal seat 148 </ b> A by the pressing portion 3.

  Accordingly, the first seal portion 1B of the elastic member 1 is pressed against the gap between the outer peripheral surface of the thimble tube 151 and the inner peripheral surface 148Ag of the seal seat 148A, and the inner peripheral surface 1Ba abuts on the outer peripheral surface of the thimble tube 151. At the same time, the outer peripheral surface 1Bb is brought into contact with the inner peripheral surface 148Ag of the seal seat 148A. The second seal portion 1C (lower surface 1b) of the elastic member 1 is in contact with the end surface 148Ae of the seal seat 148A. Further, the third seal portion 1D of the elastic member 1 is pressed against and brought into contact with the annular recess 148Af.

  As described above, the seal jig of the present embodiment includes seal portions (first seal portion 1B, second seal portion 1C, and third seal) disposed at least at three locations between the conduit tube 148 side and the thimble tube 151 side. Part 1 </ b> D), a casing 2 covering the elastic member 1, and a pressing part 3 that applies a pressing force to each seal part of the elastic member 1 via the casing 2.

  According to this sealing jig, when system decontamination is performed, even if the internal pressure of the reactor cooling system (RCS: Reactor Coolant System) is set to an intermediate pressure (for example, about 2.75 MPa), it can withstand this intermediate pressure. In addition, water leakage between the end of the conduit tube 148 and the thimble tube 151 can be prevented by the seal portions (first seal portion 1B, second seal portion 1C, and third seal portion 1D). As a result, the seal between the end of the conduit tube 148 and the thimble tube 151 can be reliably performed. Moreover, according to this sealing jig, the thimble tube includes the casing 2 that covers the elastic member 1 and the pressing portion 3 that applies a pressing force to each sealing portion of the elastic member 1 via the casing 2. The work of remodeling (cutting, welding, etc.) in the middle part of the drawing 151 is unnecessary, and water leakage between the end of the conduit tube 148 and the thimble tube 151 can be prevented. As a result, the seal between the end of the conduit tube 148 and the thimble tube 151 can be easily performed without increasing the work cost.

  In addition, since the sealing jig of this embodiment can endure medium pressure, it can be used in common as a low pressure seal, the low pressure seal can be omitted, the equipment cost is reduced, and the storage location of the sealing jig Can also be suppressed.

  In the sealing jig of the present embodiment, the elastic member 1 is formed in an annular shape so as to surround the outer periphery of the thimble tube 151, and has a notch 1A that is open to the thimble tube 151 so as to be insertable from the radial direction. Thus, the first seal portion 1B can be brought into contact with the outer peripheral surface of the thimble tube 151 and the inner peripheral surface 148Ag of the seal seat 148A and is inserted into the gap between the outer peripheral surface of the thimble tube 151 and the inner peripheral surface 148Ag of the seal seat 148A. And a second seal portion 1C that contacts the end surface 148Ae of the seal seat 148A, and a third seal portion 1D that is inserted into the annular recess 148Af of the seal seat 148A. Further, the casing 2 is formed so as to surround the elastic member 1 and the end face 148Ae of the seal seat 148A, and is divided into two so as to be arranged in the thimble tube 151 from the radial direction, and along the outer shape of the inner casing 2A. The outer casing 2B having a notch groove 2Bd that is formed in the thimble tube 151 and opened in the radial direction in the thimble tube 151 and in the inner casing 2A is desirable. The pressing portion 3 is preferably configured to press the casing 2 in the axial direction toward the seal seat 148A.

  According to this sealing jig, the end portion of the conduit tube 148 and the thimble are formed by the first seal portion 1B, the second seal portion 1C and the third seal portion 1D of the elastic member 1, and the inner casing 2A and the outer casing 2B of the casing 2. The conduit tube 148 can be surely sealed with the tube 151 and can be easily mounted by the cut 1A of the elastic member 1, the inner casing 2A divided into two parts, and the cutout groove 2Bd of the outer casing 2B. It is possible to easily perform a seal between the end of the tube and the thimble tube 151.

  Moreover, the sealing jig attachment method of this embodiment inserts the elastic member 1 from the radial direction of the thimble tube 151 via the notch 1A, and the position of the inner casing 2A divided into two from the position of the notch 1A of the elastic member 1 The inner casing 2A is disposed on the thimble tube 151 from the radial direction so as to remove the inner casing 2A, and the outer casing 2B is removed from the two-divided position of the inner casing 2A so that the position of the notch groove 2Bd of the outer casing 2B is removed. 2A is inserted from the radial direction, and the casing 2 is pressed toward the seal seat 148A by the pressing portion 3 in the axial direction.

  According to this sealing jig mounting method, the position of the cut 1A of the elastic member 1 and the position of the inner casing 2A divided into two are removed, the position of the inner casing 2A divided into two and the position of the notch groove 2Bd of the outer casing 2B By removing the, the seal between the end of the conduit tube 148 and the thimble tube 151 can be surely performed, and the seal between the end of the conduit tube 148 and the thimble tube 151 is facilitated for easy mounting. Can be realized.

  FIG. 10 is a longitudinal sectional view of another example of the sealing jig according to the present embodiment. FIG. 11 is a plan view showing a part of another example of the sealing jig according to the present embodiment. FIG. 12 is a side view showing a part of another example of the sealing jig according to the present embodiment. FIG. 13 is a plan view showing a part of another example of the sealing jig according to the present embodiment. FIG. 14 is a side view showing a part of another example of the sealing jig according to the present embodiment.

  Another example of the sealing jig shown in FIGS. 10 to 14 can perform sealing between the end of the conduit tube 148 and the thimble tube 151 corresponding to a configuration different from the high-pressure seal described above. .

  FIG. 10 shows a state where the thimble tube 151 is partially pulled out from the conduit tube 148. As indicated by a two-dot chain line, the conduit tube 148 is provided with a seal seat 148C at the end thereof. Although not shown in the drawing, the seal seat 148C has a ferrule 148Aa in the same manner as described above, and an annular ferrule 148Ab is fitted, and a nut 148Ac is screwed. The seal seat 148C has a conical ferrule 148Ca formed in the upper part in the axial direction. A male thread portion 148Cb is formed on the upper side of the ferrule 148Ca. On the other hand, the seal seat 151C is provided in the middle of the thimble tube 151. The seal seat 151C is formed with a ferrule 151Ca that fits with the ferrule 148Ca of the seal seat 148C. The seal seat 151C is formed with a nut 151Cb that is screwed into the male thread portion 148Cb of the seal seat 148C. Accordingly, the seal seat 148C and the seal seat 151C constitute a high-pressure seal maintained in a state where the ferrule 148Ca and the ferrule 151Ca are fitted to each other by screwing the nut 151Cb into the male screw portion 148Cb. Sealing is performed so as to prevent water leakage between the end of the conduit tube 148 and the thimble tube 151. A neutron detector (for example, shown by a one-dot chain line in FIG. 4) is inserted into the thimble tube 151 while being sealed by the high-pressure seal.

  In such a configuration, at the time of periodic inspection, the thimble tube 151 is withdrawn from the end of the conduit tube 148 in a separate chamber at least for several meters extracted from the fuel assembly 120. Specifically, as shown in FIG. 10, the nut 151Cb is loosened and removed from the male thread portion 148Cb, whereby the seal seats 148C and 151C are separated and the thimble tube 151 is moved upward in the axial direction (in the direction of the arrow in FIG. 6). ). At the time of periodic inspection, water is filled in the cavity of the reactor vessel 101. Therefore, the end portion of the conduit tube 148 and the middle portion where the thimble tube 151 is pulled out for the purpose of preventing water leakage due to the water head pressure. Is provided with a low pressure seal (for example, withstand pressure of about 1 MPa). Although the low-pressure seal is not clearly shown in the drawing, a cylindrical seal member is inserted into a gap between the ferrule 148Ca of the seal seat 148C and the outer peripheral surface of the thimble tube 151, and the seal member is interposed via the casing and the casing surrounding the seal member. A pressing portion that presses the inside of the gap.

  In another example of the seal jig of the present embodiment, when system decontamination is performed, the internal pressure of the reactor cooling system (RCS: Reactor Coolant System) needs to be an intermediate pressure (for example, about 2.75 MPa). This prevents water leakage between the end of the conduit tube 148 and the thimble tube 151 so that it can withstand medium pressure.

  The sealing jig of this embodiment includes an elastic member 11, a casing 12, and a pressing portion 13.

  As shown in FIGS. 10 to 12, the elastic member 11 includes a first seal portion 11B, a second seal portion 11C, and a third seal portion 11D.

  The first seal portion 11 </ b> B is formed in an annular shape with an elongated sphere that penetrates the center in a manner that surrounds the outer periphery of the thimble tube 151. Further, the first seal portion 11B is formed with a cut 11Ba. The notch 11Ba is provided so as to cut the annular shape of the first seal portion 11B obliquely with respect to the axial direction at one location, and the first seal portion 11B is diametrically (crossed (perpendicular to the axial direction) in the thimble tube 151. ) Open to be able to insert from the direction).

  11C of 2nd seal parts are formed in the cyclic | annular form which the center penetrated in the aspect surrounding the outer periphery of the conduit tube 148. As shown in FIG. Further, the second seal portion 11C is formed with a cut 11Ca. The notch 11Ca is provided so as to open the annular shape of the second seal portion 11C at an angle with respect to the axial direction, and the second seal portion 11C is formed in the conduit tube 148 in the radial direction (crossed (orthogonal to the axial direction)). ) Open to be able to insert from the direction).

  The third seal portion 11D is provided as a pair on both sides of the central axis S, and connects the first seal portion 11B and the second seal portion 11C. Accordingly, the first seal portion 11B, the second seal portion 11C, and the third seal portion 11D are formed in an endless manner.

  That is, the elastic member 11 has seal portions 11B, 11C, and 11D disposed at least at three positions between the conduit tube 148 side and the thimble tube 151 side.

  As shown in FIGS. 10, 13, and 14, the casing 12 is formed so as to surround the outer periphery of the conduit tube 148 and a part of the thimble tube 151 including the end of the conduit tube 148. Moreover, the casing 12 is formed in two so that it can be arranged from the radial direction of the conduit tube 148 and the thimble tube 151. In addition, the casing 12 is formed with an endless receiving groove 12Aa for receiving the first seal portion 11B, the second seal portion 11C, and the third seal portion 11D on the two opposing surfaces 12A. Further, the casing 12 is formed with a female screw hole 12Ab penetrating through the two opposing surfaces 12A. A plurality of female screw holes 12Ab are provided so as to surround the outside of the housing groove 12Aa. In addition, the housing 12 is formed with a housing recess 12Ac that houses the seal seat 148C and nut 148Ac at the end of the conduit tube 148 on the two opposing surfaces 12A. In addition, the casing 12 is provided with an insertion recess 12Ad through which the conduit tube 148 is inserted through the casing 12 while penetrating the casing 12, in the two opposing surfaces 12A. In addition, the casing 12 is provided with an insertion recess 12Ae through which the thimble tube 151 is inserted through the casing 12 while passing through the housing recess 12Ac in the two opposing surfaces 12A.

  That is, the casing 12 covers the elastic member 11.

  As shown in FIG. 10, the pressing portion 13 is a screw that is screwed into the female screw hole 12 </ b> Ab of the casing 12. That is, the pressing portion 13 applies a pressing force that brings the opposing surface 12 </ b> A of the casing 12 into close proximity and sandwiches and presses the elastic member 11 between the opposing surfaces 12 </ b> A.

  Another example of the sealing jig of the present embodiment configured as described above inserts the first seal portion 11B of the elastic member 11 from the radial direction of the thimble tube 151 through the cut 11Ba. Further, the second seal portion 11C of the elastic member 11 is inserted from the radial direction of the conduit tube 148 through the notch 11Ca. Next, the conduit tube 148 and the thimble are formed by dividing the casing 12 into two so as to remove the two-divided position of the casing 12 from the position of the cut 11Ba of the first seal portion 11B and the position of the cut 11Ca of the second seal portion 11C. It arrange | positions from the radial direction of the tube 151. FIG. Next, it presses so that 12 A of opposing surfaces 12A of the casing 12 may be contacted by the press part 13. FIG.

  As a result, the first seal portion 11B of the elastic member 11 surrounds the outer peripheral surface of the thimble tube 151 while being accommodated in the casing 12, and comes into contact with the outer peripheral surface. The second seal portion 11 </ b> C of the elastic member 11 surrounds the outer peripheral surface of the conduit tube 148 while being accommodated in the casing 12 and abuts on the outer peripheral surface. Further, the third seal portion 11D of the elastic member 11 is accommodated in the casing 12 while the first seal portion 11B and the second seal portion 11C are connected to each other, and the seal seat at the end of the conduit tube 148 is disposed inside the ring. Surrounds 148C and nut 148Ac.

  As described above, another example of the seal jig according to the present embodiment is a seal portion (first seal portion 11B, second seal portion 11C) disposed at least at three positions between the conduit tube 148 side and the thimble tube 151 side. , A third seal portion 11D), a casing 12 covering the elastic member 11, and a pressing portion 13 that applies a pressing force to each sealing portion of the elastic member 11 via the casing 12. .

  According to this sealing jig, when system decontamination is performed, even if the internal pressure of the reactor cooling system (RCS: Reactor Coolant System) is set to an intermediate pressure (for example, about 2.75 MPa), it can withstand this intermediate pressure. In addition, water leakage between the end of the conduit tube 148 and the thimble tube 151 can be prevented by the respective seal portions (the first seal portion 11B, the second seal portion 11C, and the third seal portion 11D). As a result, the seal between the end of the conduit tube 148 and the thimble tube 151 can be reliably performed. Moreover, according to this sealing jig, the thimble tube includes the casing 12 covering the elastic member 11 and the pressing portion 13 that applies a pressing force to each sealing portion of the elastic member 11 via the casing 12. The work of remodeling (cutting, welding, etc.) in the middle part of the drawing 151 is unnecessary, and water leakage between the end of the conduit tube 148 and the thimble tube 151 can be prevented. As a result, the seal between the end of the conduit tube 148 and the thimble tube 151 can be easily performed without increasing the work cost.

  In addition, since the other examples of the seal jig of this embodiment can withstand medium pressure, it can be used in common as a low pressure seal, the low pressure seal can be omitted, the equipment cost is reduced, and the seal The storage location of the jig can also be suppressed.

  Further, in another example of the sealing jig of the present embodiment, the elastic member 11 has a notch 11Ba that is formed so as to surround the outer periphery of the thimble tube 151 and opens to the thimble tube 151 so as to be insertable from the radial direction. The first seal portion 11B formed in this manner and the second seal portion formed so as to surround the outer periphery of the conduit tube 148 and having a notch 11Ca that can be inserted into the conduit tube 148 from the radial direction. 11C and a pair of third seal portions 11D that connect the first seal portion 11B and the second seal portion 11C, and the casing 12 includes an end portion of the conduit tube 148, and part of the conduit tube 148 and the thimble tube 151. Of the conduit tube 148 and the thimble tube 151 in the radial direction. It is formed so as to be divided into two parts, and has an accommodation groove 12Aa for accommodating the first seal part 11B, the second seal part 11C, and the third seal part 11D on the two opposing faces 12A. The pressing portion 13 is preferably configured to approach and press the two divided facing surfaces 12A of the casing 12.

  According to this sealing jig, the seal between the end of the conduit tube 148 and the thimble tube 151 is sealed by the first seal portion 11B, the second seal portion 11C and the third seal portion 11D of the elastic member 11 and the casing 12. It can be surely performed, and the cuts 11Ba and 11Ca of the elastic member 11 and the casing 12 are divided into two parts so that the mounting is easy, and the end portion of the conduit tube 148 and the thimble tube 151 are easily sealed. Can be realized.

  Moreover, the sealing jig attachment method of this embodiment inserts the 1st seal part 11B of the elastic member 11 from the radial direction of the thimble tube 151 via notch 11Ba, and cuts the 2nd seal part 11C of the elastic member 11. It inserts from the radial direction of the conduit tube 148 via the notch 11Ca, and removes the two-divided position of the casing 12 from the position of the notch 11Ba of the first seal part 11B and the position of the notch 11Ca of the second seal part 11C. The two divided casings 12 are arranged from the radial direction of the conduit tube 148 and the thimble tube 151, and are pressed by the pressing portion 13 so as to contact the two divided facing surfaces 12 </ b> A of the casing 12.

  According to this sealing jig mounting method, the position of the cut 11Ba of the first seal portion 11B of the elastic member 11 and the position of the casing 12 divided into two are removed, and the position of the cut 11Ca of the second seal portion 11C and the casing 12 are removed. By removing the two split positions, the seal between the end of the conduit tube 148 and the thimble tube 151 can be surely performed, and the end of the conduit tube 148 and the thimble tube 151 can be easily attached. It is possible to easily perform the sealing between the two.

  By the way, other examples of the sealing jig of this embodiment can be attached even if it is the structure of the end part of the conduit tube 148 of the form shown in FIG. Therefore, as a method for operating the sealing jig, a seal between the end of the conduit tube 148 and the thimble tube 151 with respect to the conduit tube 148 provided in the reactor vessel 101 and the thimble tube 151 inserted into the conduit tube 148 is used. In performing the above, the seal jig of this embodiment and other examples of the seal jig are selected and used according to the difference in the end shape of the conduit tube 148, while other examples of the seal jig are shared and used.

  According to this sealing jig operation method, a relatively small casing 2 is obtained by selecting and using the sealing jig of this embodiment and another example of the sealing jig according to the difference in the end shape of the conduit tube 148. By applying the sealing jig of the present embodiment having a low manufacturing cost, the cost can be suppressed. On the other hand, by sharing and using another example of the seal jig, it is possible to improve the workability by sharing one type of the seal jig.

DESCRIPTION OF SYMBOLS 1 Elastic member 1a Upper surface 1b Lower surface 1c Inner peripheral surface 1d Outer peripheral surface 1A Notch 1B First seal part 1Ba Inner peripheral surface 1Bb Outer peripheral surface 1C Second seal part 1D Third seal part 2 Casing 2A Inner casing 2Aa Cylindrical part 2Ab Closure Part 2Ac Through hole 2Ad Flange part 2B Outer casing 2Ba Tubular part 2Bb Closed part 2Bc Through hole 2Bd Notch groove 2Be Protruding part 3 Press part 3A Press member 3Aa Through hole 3Ab Male thread part 3Ac Nut 3Ad Fitting part 3Ae Notch part 3Ae Notch part 3Ae Part 3Ba Support part body 3Bb Female thread part 3Bc Fixing part 3Bca Fitting recess 3Bcb Fixing tool 3Bcc Screw 3Bd Fixing nut 3Be Notch groove 11 Elastic member 11B First seal part 11Ba Notch 11C Second seal part 11Ca Third seal 11D Part 12 Casing 12A Opposite 12Aa receiving groove 12Ab female screw hole 12Ac receiving recess 12Ad insertion recess 12Ae insertion recess 13 pressing portion 148 conduit tube 148A seal seat 148Aa ferrule 148Ab ferrule 148Ac nut 148Ad flange portion 148Ae ring surface 148Ae end surface 148Ae Ferrule 148Cb Male thread part 151 Thimble tube 151A Seal seat 151Aa Ferrule 151Ab Ferrule 151Ac Nut 151Ad Flange part 151Ae End face 151Af Cylindrical part 151B Clamp part 151C Seal seat 151C Shaft 151Cb Nut

Claims (6)

A sealing jig that performs a seal between an end of a conduit tube provided in a nuclear reactor vessel and a thimble tube inserted into the conduit tube,
An elastic member having seal portions disposed at least in three places between the conduit tube side and the thimble tube side;
A casing covering the elastic member;
A pressing portion that applies a pressing force to each of the sealing portions of the elastic member via the casing;
Including sealing jig. The conduit tube has an inner peripheral surface that is provided at an end of the conduit tube and faces the outer peripheral surface of the thimble tube with a gap, and has an end surface facing the axial direction of the conduit tube, and the shaft of the conduit tube at the end surface It has a seal seat formed with an annular recess surrounding it,
The elastic member is formed in an annular shape so as to surround the outer periphery of the thimble tube, and is formed to have a notch that opens into the thimble tube so as to be insertable from the radial direction, and the outer peripheral surface of the thimble tube and A first seal portion that can be brought into contact with the inner peripheral surface of the seal seat and inserted into the gap; a second seal portion that comes into contact with the end surface; and a third seal portion that is inserted into the annular recess. ,
The casing is formed so as to surround the elastic member and the end face of the seal seat, and is formed along the outer shape of the inner casing divided into two so as to be arranged in the thimble tube from the radial direction, and the outer casing, The thimble tube and the inner casing are configured to include an outer casing having a notch groove that is open so as to be disposed from the radial direction,
The pressing portion is configured to press the casing in the axial direction toward the seal seat.
The sealing jig according to claim 1. The elastic member is formed so as to surround an outer periphery of the thimble tube, and has a first seal portion formed so as to have an opening that can be inserted into the thimble tube from a radial direction, and an outer periphery of the conduit tube A second seal portion formed so as to surround the conduit tube and having a notch that can be inserted into the conduit tube from the radial direction, and a pair that connects the first seal portion and the second seal portion And a third seal portion,
The casing includes an end portion of the conduit tube and is formed so as to surround the outer periphery of a part of the conduit tube and the thimble tube, and is formed in two so as to be arranged from a radial direction of the conduit tube and the thimble tube. And having a housing groove for housing the first seal portion, the second seal portion and the third seal portion on the opposing surfaces divided into two,
The pressing part is configured to approach and press the two divided opposing surfaces of the casing,
The sealing jig according to claim 1.   In performing sealing between the end portion of the conduit tube and the thimble tube, the sealing jig according to claim 2 and the sealing jig according to claim 3 according to a difference in an end portion shape of the conduit tube. A seal jig operating method that uses the seal jig according to claim 3 in common while selecting and using the seal jig.   3. A sealing jig mounting method using a sealing jig according to claim 2, wherein a seal between the end of the conduit tube and the thimble tube is used, wherein the elastic member is inserted into the thimble tube through the notch. The inner casing is disposed in the thimble tube from the radial direction so as to disengage the two-divided position of the inner casing from the notch position of the elastic member, and the 2 of the inner casing is The outer casing is inserted into the thimble tube and the inner casing from the radial direction so as to remove the position of the notch groove of the outer casing from the division position, and the shaft is directed toward the seal seat by the pressing portion. Seal jig mounting method that pushes in the direction. In performing sealing between the end of the conduit tube and the thimble tube, a sealing jig mounting method using the sealing jig according to claim 3,
The first seal portion of the elastic member is inserted from the radial direction of the thimble tube through the cut, and the second seal portion is inserted from the radial direction of the conduit tube through the cut, The casing is arranged from the radial direction of the conduit tube and the thimble tube so as to remove the two-divided position of the casing from the cut position of the first seal portion and the cut position of the second seal portion. And the sealing jig attachment method of pressing so that the 2nd opposing surface of the said casing may be contacted by the said press part.

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