JP6087660B2 - Reactor vessel lid structure - Google Patents

Description

  The present invention relates to a reactor vessel lid structure that is disposed on an upper portion of a reactor vessel and supports a control rod drive device that takes a control rod into and out of a reactor core.

  For example, a nuclear power plant equipped with a pressurized water reactor (PWR: Pressurized Water Reactor) uses light water as a reactor coolant and a neutron moderator to produce high-temperature and high-pressure water that does not boil throughout the core, and this high-temperature and high-pressure water is steamed. It is sent to a generator to generate steam by heat exchange, and this steam is sent to a turbine generator to generate electricity.

  In such a pressurized water reactor, neutrons generated in the core are absorbed by a control rod, thereby adjusting the number of neutrons and controlling the reactor output. For this reason, the control rods are distributed and incorporated in advance in the fuel assemblies constituting the reactor core, and are controlled collectively. The plurality of control rods are taken in and out of the core by a control rod drive device (CRDM) arranged at the upper part of the reactor vessel.

  In general, a magnetic jack drive system is often applied to the control rod drive device and is supported on the upper portion of the reactor vessel lid. The control rod drive coil needs to be cooled because it becomes hot due to energization of the coil, and the reactor vessel lid structure is provided with a cooling device. In a general reactor vessel lid, a control rod drive device is supported inside an earthquake resistant support supported by the reactor building and the lifting rod, and the control rod drive device is installed between the earthquake resistant support and the reactor vessel lid. A cooling air passage is arranged outside. Examples of such a reactor vessel lid structure include those described in Patent Documents 1-3 below.

Japanese Patent Laid-Open No. 01-097898 JP-A-60-183589 JP 2009-198400 A

  The conventional reactor vessel lid structure supports the control rod drive device with an upper earthquake-resistant support, and only forms a cooling air passage between the earthquake-resistant support and the reactor vessel lid. There is a desire to provide a support function for the control rod drive device in the cooling air passage forming portion to improve the earthquake resistance of the control rod drive device.

  The present invention solves the above-described problems, and an object of the present invention is to provide a reactor vessel lid structure that can improve earthquake resistance.

  In order to achieve the above object, a reactor vessel lid structure according to the present invention includes a reactor vessel lid connected from a seismic support via a plurality of lifting rods, and is disposed above the reactor vessel lid. A control rod driving device supported by an earthquake-resistant support, a support member fixed to a rod connecting portion of each lifting rod in the reactor vessel lid, an intake portion for taking cooling air into the control rod driving device from the outside, A lower duct disposed around the lower portion of the control rod driving device and supported by the support member and guiding the cooling air sucked from the intake portion upward; and arranged around the upper portion of the control rod driving device; An upper duct that is supported by the support and that discharges cooling air to the outside; and a connection duct that connects the lower duct and the upper duct. Is shall.

  Therefore, the lower duct arranged around the lower part of the control rod drive unit is supported by the support member, the upper duct arranged around the upper part of the control rod drive unit is supported by the seismic support, and the lower duct and the upper duct are connected ducts. As a result of the connection, the lower duct and the upper duct are supported by different parts. Therefore, the seismic resistance of the lower duct and the seismic resistance of the upper duct are ensured independently, and the flow of cooling air from the lower duct to the upper duct can be secured by the connecting duct, and the cooling performance of the control rod drive unit The earthquake resistance can be improved while maintaining the above.

  In the nuclear reactor vessel lid structure according to the present invention, the connection duct is a flexible exhaust duct capable of absorbing vibration transmitted between the lower duct and the upper duct.

  Therefore, since the connecting duct is a flexible exhaust duct, the vibration of the lower duct is not transmitted to the upper duct, and the vibration of the upper duct is not transmitted to the lower duct. Can improve the earthquake resistance.

  In the nuclear reactor vessel lid structure according to the present invention, the support member is fixed so as to sandwich the rod connecting portion, and the lower duct is mounted on the upper support surface of the support member and is bolted. It is characterized by that.

  Therefore, the lower duct is firmly fixed to the reactor vessel lid by placing the lower duct on the upper support surface of the support member fixed to the rod connecting portion and fastening the bolt, and the earthquake resistance of the lower duct Can be improved.

  In the reactor vessel lid structure of the present invention, the support member is provided with an attachment portion along a circumferential direction of the reactor vessel lid, and the attachment portion is bolted to the reactor vessel lid. Yes.

  Therefore, the support member is fixed to the rod connecting portion, and the integral attachment portion is bolted along the circumferential direction of the reactor vessel lid, thereby firmly fixing the support member to the reactor vessel lid. be able to.

  In the nuclear reactor vessel lid structure of the present invention, the support member is divided and provided corresponding to each of the rod connecting portions.

  Accordingly, since the support member is divided corresponding to each rod connecting portion, the position of the supporting member corresponding to each rod connecting portion is not shifted even if the support member is deformed by receiving heat from the reactor vessel lid. The lower duct can be supported stably at all times.

  In the nuclear reactor vessel lid structure according to the present invention, each lifting rod is characterized in that a lower part is connected to the rod connecting part or the lower duct.

  Therefore, the reactor vessel lid can be properly supported by the lifting rod.

  According to the reactor vessel lid structure of the present invention, the lower duct arranged around the lower part of the control rod drive unit is supported by the support member, and the upper duct arranged around the upper part of the control rod drive unit serves as an earthquake-resistant support. Since it is supported and the lower duct and the upper duct are connected by the connecting duct, it is possible to improve the earthquake resistance while maintaining the cooling performance of the control rod driving device.

FIG. 1 is a longitudinal sectional view showing a reactor vessel lid structure according to an embodiment of the present invention. FIG. 2 is a horizontal sectional view showing the reactor vessel lid structure of the present embodiment. FIG. 3 is a schematic diagram showing the lower duct. FIG. 4 is a side view illustrating a support state of the lower duct by the support member. FIG. 5 is a front view showing a support state of the lower duct. FIG. 6 is a schematic view showing the reactor vessel lid structure of the present embodiment. FIG. 7 is a schematic configuration diagram of a nuclear power plant. FIG. 8 is a longitudinal sectional view showing a pressurized water reactor.

  Exemplary embodiments of a reactor vessel lid structure according to the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this Example, Moreover, when there exists multiple Example, what comprises combining each Example is also included.

  1 is a longitudinal sectional view showing a reactor vessel lid structure according to one embodiment of the present invention, FIG. 2 is a horizontal sectional view showing a reactor vessel lid structure according to this embodiment, and FIG. 3 is a lower duct. FIG. 4 is a side view showing the support state of the lower duct by the support member, FIG. 5 is a front view showing the support state of the lower duct, and FIG. 6 is the reactor vessel lid structure of this embodiment. FIG. 7 is a schematic configuration diagram of a nuclear power plant, and FIG. 8 is a longitudinal sectional view showing a pressurized water reactor.

  The nuclear reactor of this embodiment uses light water as a reactor coolant and neutron moderator, and generates high-temperature and high-pressure water that does not boil over the entire core and sends this high-temperature and high-pressure water to a steam generator to generate steam by heat exchange. This is a pressurized water reactor (PWR) that generates electricity by sending this steam to a turbine generator.

  In the nuclear power plant having the pressurized water reactor of the present embodiment, as shown in FIG. 7, the reactor containment vessel 11 stores therein the pressurized water reactor 12 and the steam generator 13, and this pressurized water type The nuclear reactor 12 and the steam generator 13 are connected via a high temperature side supply pipe 14 and a low temperature side supply pipe 15, and a pressurizer 16 is provided in the high temperature side supply pipe 14, and the low temperature side supply pipe is provided. A primary cooling water pump 17 is provided at 15. In this case, light water is used as a moderator and primary cooling water (cooling material), and the primary cooling system maintains a high pressure state of about 150 to 160 atm by the pressurizer 16 in order to suppress boiling of the primary cooling water in the core. You are in control.

  Accordingly, in the pressurized water reactor 12, light water is heated as the primary cooling water by the low-enriched uranium or MOX as the fuel (nuclear fuel), and the high temperature primary cooling water is maintained at a predetermined high pressure by the pressurizer 16. , And is sent to the steam generator 13 through the high temperature side supply pipe 14. In the steam generator 13, heat exchange is performed between the high-temperature and high-pressure primary cooling water and the secondary cooling water, and the cooled primary cooling water is returned to the pressurized water reactor 12 through the low-temperature side supply pipe 15. .

  The steam generator 13 is connected to a steam turbine 32 via a pipe 31 for supplying heated secondary cooling water, that is, steam, and a main steam isolation valve 33 is provided in the pipe 31. The steam turbine 32 includes a high-pressure turbine 34 and a low-pressure turbine 35, and a generator (power generation device) 36 is connected to the steam turbine 32. Further, the high pressure turbine 34 and the low pressure turbine 35 are provided with a moisture separation heater 37 therebetween, and a cooling water branch pipe 38 branched from the pipe 31 is connected to the moisture separation heater 37, while the high pressure turbine 34 and the moisture separation heater 37 are connected by a low-temperature reheat pipe 39, and the moisture separation heater 37 and the low-pressure turbine 35 are connected by a high-temperature reheat pipe 40.

  Further, the low-pressure turbine 35 of the steam turbine 32 includes a condenser 41. The condenser 41 is connected to a turbine bypass pipe 43 having a bypass valve 42 from the pipe 31, and is also supplied with cooling water (for example, , Seawater) is connected to a water intake pipe 44 and a drain pipe 45. The intake pipe 44 has a circulating water pump 46, and the other end portion thereof is disposed in the sea together with the drain pipe 45.

  The condenser 41 is connected to a pipe 47, and is connected to a condensate pump 48, a ground condenser 49, a condensate demineralizer 50, a condensate booster pump 51, and a low-pressure feed water heater 52. The piping 47 is connected to a deaerator 53 and is provided with a main feed water pump 54, a high-pressure feed water heater 55, and a main feed water control valve 56.

  Therefore, the steam generated by exchanging heat with the high-temperature and high-pressure primary cooling water in the steam generator 13 is sent to the steam turbine 32 (from the high-pressure turbine 34 to the low-pressure turbine 35) through the pipe 31. The turbine 32 is driven to generate power by the generator 36. At this time, the steam from the steam generator 13 drives the high-pressure turbine 34, and then the moisture contained in the steam is removed and heated by the moisture separation heater 37, and then the low-pressure turbine 35 is driven. Then, the steam that has driven the steam turbine 32 is cooled using seawater in the condenser 41 to become condensed water, and the ground condenser 49, the condensate demineralizer 50, the low pressure feed water heater 52, the deaerator 53, the high pressure It returns to the steam generator 13 through the feed water heater 55 or the like.

  In the pressurized water reactor 12 of the nuclear power plant configured as described above, as shown in FIG. 8, the reactor vessel 61 includes a reactor vessel main body 62 and its reactor so that the reactor internal structure can be inserted therein. The reactor vessel lid (upper mirror) 63 is mounted on the upper portion. The reactor vessel lid 63 is fixed to the reactor vessel body 62 by a plurality of stud bolts 64 and nuts 65 so as to be opened and closed. Yes.

  The reactor vessel main body 62 has a cylindrical shape whose upper portion can be opened by removing the reactor vessel lid 63 and whose lower portion is closed by a lower mirror 66 having a hemispherical shape. The reactor vessel body 62 is formed with an inlet nozzle (inlet nozzle) 67 for supplying light water (coolant) as primary cooling water and an outlet nozzle (exit nozzle) 68 for discharging light water at the upper part. Yes. In addition to the inlet nozzle 67 and the outlet nozzle 68, the reactor vessel main body 62 is formed with a water injection nozzle (water injection pipe stand) (not shown).

  In the reactor vessel main body 62, the upper core support plate 69 is fixed above the inlet nozzle 67 and the outlet nozzle 68, while the lower core support plate 70 is fixed in the vicinity of the lower mirror 66 below. Has been. The upper core support plate 69 and the lower core support plate 70 have a disk shape and are formed with a number of communication holes (not shown). The upper core support plate 69 is connected to an upper core plate 72 formed with a plurality of communication holes (not shown) below via a plurality of core support rods 71.

  In the reactor vessel main body 62, a cylindrical core tank 73 having a cylindrical shape is disposed with a predetermined gap from the inner wall surface. The core tank 73 is connected to the upper core plate 72 at the upper part and has a disk shape at the lower part. Thus, a lower core plate 74 having a plurality of communication holes (not shown) is connected. The lower core plate 74 is supported by the lower core support plate 70. That is, the core tank 73 is suspended and supported by the lower core support plate 70 of the reactor vessel main body 62.

  The core 75 is formed by an upper core plate 72, a core tank 73, and a lower core plate 74, and the core 75 has a large number of fuel assemblies 76 disposed therein. Although not shown, the fuel assembly 76 is configured by bundling a large number of fuel rods in a lattice pattern by 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 75 has a large number of control rods 77 arranged therein. The large number of control rods 77 are combined at the upper end portion into a control rod cluster 78 that can be inserted into the fuel assembly 76. A number of control rod cluster guide tubes 79 are fixed to the upper core support plate 69 so as to pass through the upper core support plate 69, and each control rod cluster guide tube 79 has a lower end control within the fuel assembly 76. It extends to the bar cluster 78.

  A reactor vessel lid 63 constituting the reactor vessel 61 has a hemispherical upper portion and is provided with a magnetic jack drive type control rod drive device 80, and is configured as a reactor vessel lid structure 81. A large number of control rod cluster guide tubes 79 extend to the control rod drive device 80 at the upper end, and the control rod cluster drive shaft 82 extends from the control rod drive device 80 in the control rod cluster guide tube 79. It extends to the fuel assembly 76 and can grip the control rod cluster 78.

  The control rod driving device 80 extends in the vertical direction and is connected to the control rod cluster 78, and a control rod cluster driving shaft 82 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 drive system.

  The reactor vessel main body 62 is provided with a number of instrumentation nozzles 83 penetrating the lower mirror 66, and each instrumentation nozzle 83 is connected to an inner instrumentation guide tube 84 at the upper end portion inside the reactor. On the other hand, a conduit tube 85 is connected to a lower end portion outside the furnace. Each in-core instrumentation guide tube 84 has an upper end connected to the lower core support plate 70, and upper and lower connecting plates 86 and 87 for suppressing vibration are attached. The thimble tube 88 is equipped with a neutron flux detector (not shown) capable of measuring a neutron flux, passes from the conduit tube 85 through the instrumentation nozzle 83 and the in-core instrumentation guide tube 84, and passes through the lower core plate 74. The fuel assembly 76 can be inserted through.

  Accordingly, the control rod drive device 80 moves the control rod cluster drive shaft 82 to extract a predetermined amount of the control rod 77 from the fuel assembly 76, thereby controlling the nuclear fission in the core 75 and generating the nuclear reactor by the generated thermal energy. The light water filled in the container 61 is heated, and high-temperature light water is discharged from the outlet nozzle 68 and sent to the steam generator 13 as described above. That is, the nuclear fuel constituting the fuel assembly 76 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 is easy to cause nuclear fission and takes away the generated heat to cool. On the other hand, by inserting the control rod 77 into the fuel assembly 76, the number of neutrons generated in the reactor core 75 is adjusted, and by inserting all the control rod 77 into the fuel assembly 76, the nuclear reactor is emergency Can be stopped.

  Further, the reactor vessel 61 has an upper plenum 89 communicating with the outlet nozzle 68 above the core 75 and a lower plenum 90 formed below. A downcomer portion 91 communicating with the inlet nozzle 67 and the lower plenum 90 is formed between the nuclear reactor vessel 61 and the reactor core 73. Accordingly, the light water flows into the reactor vessel main body 62 from the inlet nozzle 67, flows down the downcomer portion 91, reaches the lower plenum 90, and is guided upward by the spherical inner surface of the lower plenum 90. Then, after passing through the lower core support plate 70 and the lower core plate 74, it flows into the core 75. The light water that has flowed into the core 75 absorbs heat energy generated from the fuel assemblies 76 constituting the core 75 to cool the fuel assemblies 76, while passing through the upper core plate 72 at a high temperature. Ascending to the upper plenum 89 and discharged through the outlet nozzle 68.

  Here, the reactor vessel lid structure 81 in the pressurized water reactor 12 will be described in detail.

  As shown in FIGS. 1, 2, and 6, the reactor vessel lid structure 81 includes a reactor vessel lid 63, a control rod driving device 80, a support member 101, an intake portion 102, a lower duct 103, and an upper duct 104. And a connecting duct 105.

  More specifically, the seismic support 111 has a disk shape and is horizontally supported by the upper structure 113 of the reactor building by a plurality of tie rods 112. And this seismic support 111 is arrange | positioned so that the control rod drive device 80 may penetrate in the center part, and this control rod drive device 80 is supported.

  Moreover, the upper duct 104 is being fixed to the lower part of the earthquake-resistant support 111. FIG. The upper duct 104 is arranged in the shape of a hollow ring around the upper portion of the control rod driving device 80, and a passage G through which cooling air flows in the circumferential direction is formed. The upper duct 104 is connected to an exhaust duct 115 at the side via an outlet duct 114, and an exhaust fan (not shown) is provided in the exhaust duct 115.

  The reactor vessel lid 63 is connected to a plurality of (in this embodiment, four) lifting rods 116 extending downward from the earthquake-resistant support 111. In the reactor vessel lid 63, four rod connecting portions 117 are fixed to the spherical surface portion 63a at equal intervals in the circumferential direction. As shown in detail in FIGS. 4 and 5, the rod connecting portion 117 is a plate material that extends along the vertical direction and the radial direction with respect to the spherical surface portion 63 a of the reactor vessel lid 63, and is fixed by welding. A connection hole 118 is formed. The lifting rod 116 is connected to a bifurcated connecting portion 119 at a lower end portion to form a connecting hole 120. The lifting rod 116 is positioned such that the connecting portion 119 sandwiches the rod connecting portion 117, the connecting bolt 121 is inserted into each connecting hole 118, 120, and the nut 122 is screwed into the connecting bolt 121. , Connected to the reactor vessel lid 63.

  The lower duct 103 is arranged in a hollow cylindrical shape around the lower portion of the control rod driving device 80, and is composed of an outer cylinder 123 and an inner cylinder 124. The outer cylinder 123 and the inner cylinder 124 are connected at their upper ends by a connecting ring 125. It is connected. In the lower duct 103, a passage A in which cooling air flows downward is formed inside the inner cylinder 124, and a passage C in which cooling air flows upward is formed between the outer cylinder 123 and the inner cylinder 124. In this case, in the lower duct 103, the inner cylinder 124 is set shorter than the outer cylinder 123, so that a space portion B that connects the passage A and the passage C is formed in the lower portion.

  The support member 101 is fixed to the rod connecting portion 117 of each lifting rod 116 in the reactor vessel lid 63. As shown in FIGS. 3 to 5, the support member 101 is divided and provided corresponding to each rod connecting portion 117, and has the same configuration. The support member 101 includes a main body portion 131 that sandwiches the rod connecting portion 117, a support portion 132 provided on the upper portion of the main body portion 131, and the reactor vessel lid 63 from both sides of the main body portion 131 (or the support portion 132). It is comprised from the two attaching parts 133 extended in the circumferential direction.

  The main body 131 has a U-shape in plan view and is disposed so as to sandwich the rod connecting portion 117 from the thickness direction. The main body 131 is screwed with fixing bolts 134 from both sides, and rotates the fixing bolts 134 to press the tips against the flat portions of the rod connecting portion 117, thereby supporting the support member 101 with the lifting rod 116. It can fix to the rod connection part 117 of this. In this case, the mounting position of the support member 101 can be adjusted by interposing the shim 135 between the main body portion 131 of the support member 101 and the inclined end surface 117a of the rod connecting portion 117.

  The support part 132 is integrally provided at the tip of the main body part 131, and an upper support surface 132a is formed. The upper support surface 132a is a surface on which the lower surface of the support portion 103a in the lower duct 103 is placed, and a stepped portion 132b having a different height in the radial direction is formed. In the lower duct 103, the fastening bolt 136 penetrates the support portion 103a from the upper portion and is screwed into the support portion 132 of the support member 101 with the lower surface of the support portion 103a placed on the upper support surface 132a. Then, it is fixed to the reactor vessel lid 63.

  Each attachment portion 133 is arranged along the circumferential direction of the reactor vessel lid 63, and is bolted by a plurality of bolts 137 passing through and screwing into the reactor vessel lid 63. In this case, the attachment portions 133 of the four support members 101 are arranged along the circumferential direction of the reactor vessel lid 63, but a gap is secured between the adjacent attachment portions 133. .

  As shown in FIGS. 1, 2, and 6, the lower duct 103 has a plurality of (four in this embodiment) openings 141 formed in the connecting ring 125 at equal intervals in the circumferential direction. A lower extension duct 142 having a passage D through which cooling air flows is connected to the opening 141. On the other hand, the upper duct 104 has a plurality of (four in this embodiment) openings 143 formed at equal intervals in the circumferential direction on the lower surface, and an upper extension duct having a passage F through which cooling air flows. 144 is connected.

  The connection duct 105 connects the upper end portion of the lower extension duct 142 and the lower end portion of the upper extension duct 144 to connect the passage D and the passage F by the passage E. The connecting duct 105 is a flexible exhaust duct that can absorb vibration transmitted between the lower duct 103 and the upper duct 104.

  Further, the lower duct 103 and the upper duct 104 are connected by the four connecting ducts 105, thereby forming the intake portion 102 for taking cooling air into the control rod driving device 80 from the outside between the connecting ducts 105. Can do.

  In the above description, the connecting portion 119 of the lifting rod 116 is connected to the rod connecting portion 117 so that the lifting rod 116 is connected to the reactor vessel lid 63. However, the lower end portion of the lifting rod 116 is It may be connected to the connecting ring 125 of the lower duct 103, and in this case, the lifting rod 116 can be shortened.

  When the exhaust fan is driven in the reactor vessel lid structure 81 configured as described above, the suction force acts on the upper duct 104 from the exhaust duct 115 and the outlet duct 114, and further from the connection duct 105 to the lower duct 103. Acting on the intake portion 101.

  Therefore, external air is taken as cooling air from the intake section 102 into the passage A of the lower duct 103. The cooling air taken into the passage A of the lower duct 103 from the intake portion 102 cools each magnetic jack driving type coil (not shown) of the control rod driving device 80 while descending the passage A. The cooling air whose temperature has risen by cooling the coils of each magnetic jack drive system turns up the space B of the lower duct 103 and rises in the passage C. The cooling air rising in the passage C of the lower duct 103 flows to the passage G of the upper duct 104 through the passage D of the lower extension duct 142, the passage E of the connection duct 105, and the passage F of the upper extension duct 144. The cooling air is discharged from the passage G of the upper duct 104 to the outside through the outlet duct 114 and the exhaust duct 115.

  Thus, in the reactor vessel lid structure of the present embodiment, the reactor vessel lid 63 connected from the earthquake-resistant support 111 via the lifting rod 116 and the reactor vessel lid 63 are arranged above the reactor vessel lid 63 to be earthquake resistant. A control rod driving device 80 supported by the support 111, a support member 101 fixed to the rod connecting portion 117 of the lifting rod 116 in the reactor vessel lid 63, and an intake portion for taking cooling air into the control rod driving device 80 from the outside 102, a lower duct 103 disposed around the lower portion of the control rod driving device 80 and supported by the support member 101 and guiding the cooling air sucked from the intake portion 102 upward, and disposed around the upper portion of the control rod driving device 80 The upper duct 104 that is supported by the seismic support 111 and discharges cooling air to the outside, the lower duct 103, and the upper duct It is provided with connection duct 105 for connecting the 04.

  Accordingly, the lower duct 103 disposed around the lower portion of the control rod driving device 80 is supported by the support member 101, and the upper duct 104 disposed around the upper portion of the control rod driving device 80 is supported by the seismic support 111, thereby lowering the lower duct. 103 and the upper duct 104 are connected by the connecting duct 105, whereby the lower duct 103 and the upper duct 104 are supported by different parts. Therefore, the seismic resistance of the lower duct 103 and the seismic resistance of the upper duct 104 are ensured independently, and the flow of cooling air from the lower duct 103 to the upper duct 104 can be secured by the connecting duct 105, and the control rod It is possible to improve the earthquake resistance while maintaining the cooling performance of the driving device 80.

  In the reactor vessel lid structure of the present embodiment, the connecting duct 105 is a flexible exhaust duct that can absorb vibration transmitted between the lower duct 103 and the upper duct 104. Therefore, since the connecting duct 105 is a flexible exhaust duct, the vibration of the lower duct 103 is not transmitted to the upper duct 104, and the vibration of the upper duct 104 is not transmitted to the lower duct 103. The earthquake resistance of the control rod driving device 80 can be improved.

  In the reactor vessel lid structure of the present embodiment, the support member 101 is fixed so as to sandwich the rod connecting portion 117, the lower surface of the lower duct 103 is placed on the upper support surface 132a of the support member 101, and is bolted. ing. Therefore, the lower duct 103 is firmly fixed to the reactor vessel lid 63 by placing the lower duct 103 on the upper support surface 132a of the support member 101 fixed to the rod connecting portion 117 and fastening the bolt with the bolt. The earthquake resistance of the lower duct 103 can be improved.

  In the reactor vessel lid structure of the present embodiment, the support member 101 is provided with an attachment portion 133 along the circumferential direction of the reactor vessel lid 63, and the attachment portion 133 is bolted to the reactor vessel lid 63. Therefore, the support portion 131 of the support member 101 is fixed to the rod connecting portion 117 and the attachment portion 133 is bolted to the reactor vessel lid 63 so that the support member 101 is firmly attached to the reactor vessel lid 63. Can be fixed to.

  In the reactor vessel lid structure of the present embodiment, the support member 101 is divided and provided corresponding to each rod connecting portion 117. Therefore, even if the support member 101 is deformed by receiving heat from the reactor vessel lid 63, the position of each support member 101 corresponding to each rod connecting portion 117 is not displaced, and the lower duct 103 is always stably supported. can do.

  In the embodiment described above, the reactor is a pressurized water reactor, but it may be a boiling water reactor.

DESCRIPTION OF SYMBOLS 12 Pressurized water reactor 61 Reactor vessel 62 Reactor vessel main body 63 Reactor vessel lid 77 Control rod 80 Control rod drive device 81 Reactor vessel lid structure 101 Support member 102 Intake part 103 Lower duct 104 Upper duct 105 Connection duct 111 Seismic support 116 Lifting rod 117 Rod connecting part 131 Main body part 132 Support part 133 Mounting part 142 Lower extension duct 144 Upper extension duct

Claims (5)

A reactor vessel lid connected from the seismic support via a plurality of lifting rods;
A control rod driving device disposed above the reactor vessel lid and supported by the seismic support;
A support member fixed to a rod connecting portion of each lifting rod in the reactor vessel lid;
An intake section for taking cooling air into the control rod drive from outside,
A lower duct disposed around the lower portion of the control rod driving device and supported by the support member and guiding the cooling air sucked from the intake portion upward;
An upper duct disposed around the upper portion of the control rod drive device and supported by the seismic support and for discharging cooling air to the outside;
A connecting duct for flowing cooling air of the lower duct to the upper duct by connecting the lower duct and the upper duct;
I have a,
The support member is fixed so as to sandwich the rod connecting portion, and the lower duct has a lower surface placed on an upper support surface of the support member and is bolted.
A reactor vessel lid structure characterized by that. 2. The reactor vessel lid according to claim 1 , wherein the support member is provided with an attachment portion along a circumferential direction of the reactor vessel lid, and the attachment portion is bolted to the reactor vessel lid. Structure. The reactor vessel lid structure according to claim 1 or 2 , wherein the connection duct is a flexible exhaust duct capable of absorbing vibration transmitted between the lower duct and the upper duct. The reactor vessel lid structure according to any one of claims 1 to 3 , wherein the support member is divided and provided corresponding to each of the rod connecting portions. The reactor vessel lid structure according to any one of claims 1 to 4 , wherein a lower portion of each lifting rod is connected to the rod connecting portion or the lower duct.

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