JP2016156737A - Heat insulating body attaching device and attaching method, and core tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To safely and easily attach a heat insulating body to a core tank.SOLUTION: A heat insulating body attaching device is equipped with a pressing jig 2 which has a rod-shaped shaft member 2A inserted in an insertion hole 161B provided so as to penetrate a heat insulating body 161, and extends outward from an outside surface of a core tank 127 to be attached to a bolt hole 127Ba provided on the outside surface of the core tank 127; and a moving member 2B which is provided so as to engaged with the shaft member 2A, and provided so as to slide in an extending direction of the shaft member 2A.SELECTED DRAWING: Figure 9

Description

  The present invention relates to an in-reactor structure disposed inside a reactor vessel, and relates to a heat shield attaching device and attaching method to a core tank in the in-core structure, and a core tank.

  The core is surrounded by a cylindrical core tank disposed in the reactor vessel, and a part of the neutrons contained in the radiation leaks through a baffle surrounding the core in the core tank. The collision of leaked neutrons with the reactor vessel structurally deteriorates the reactor vessel due to embrittlement, and therefore a thermal shield is interposed between the reactor core vessel and the reactor vessel. The heat shield is configured as an arc-shaped plate along the outer shape of the reactor core, and is fixed to the outer surface of the reactor core with bolts. Further, since the maximum leakage of neutrons occurs near the corner portion of the core, the thermal shield is provided at a position of 45 ° in the circumferential direction facing the corner portion of the core (see, for example, Patent Document 1). .

JP-A-4-318494

  By the way, the pressurized water reactor described above periodically inspects various structures in order to ensure sufficient safety and reliability, and repairs necessary parts as necessary, Replace it with a new one. When the reactor internal structure is newly replaced, a heat shield is fixed to the outer surface of the assembled core tank with bolts. Since the heat shield is configured as an arc-shaped plate body along the cylindrical shape of the reactor core tank, when mounting, the mounting surface of the heat shield body is pressed against the outer surface of the reactor core tank, It is necessary to make contact with the arc and the arc on the mounting surface of the heat shield and fix them with bolts. This pressing operation of the heat shield was performed manually by an operator.

  However, one thermal shield provided at a position of 45 ° in the circumferential direction facing the corner portion of the core is about 700 kg, and a plurality of workers are required to press it against the core tank. It will be. Further, if a plurality of workers are required, there is a possibility that an accident in which fingers are caught between the heat shield and the core tank in the pressing operation may occur. In addition, after confirming the contact with the heat shield, the pressure applied when attaching the heat shield may differ depending on the work performed manually. I have to fix it.

  The present invention solves the above-described problems, and an object of the present invention is to provide a heat shield attachment device, an attachment method, and a core tank that can safely and easily attach a heat shield to the core tank.

  In order to achieve the above object, a thermal shield mounting apparatus according to the present invention is a thermal shield mounting apparatus for mounting a thermal shield to an outer surface of a reactor core tank disposed in a reactor vessel. And inserted into an insertion hole provided through the heat shield, and attached to a bolt hole provided on the outer surface of the core tank so as to extend outward from the outer surface of the core tank. A pressing jig having a rod-shaped shaft member and a moving member provided so as to be engageable with the shaft member and slidably movable along an extending direction of the shaft member is provided. To do.

  According to this heat shield mounting apparatus, the heat shield in which the shaft member attached to the outer surface of the reactor core is inserted by sliding the moving member of the pressing jig along the extending direction of the shaft member. The body is pressed against the outer surface of the core tank by the moving member. For this reason, it is not necessary to require a large number of workers for the operation of pressing the heat shield against the core tank, and only one person is required. Moreover, since many workers are not required, it is possible to reduce the occurrence of an accident in which the workers pinch fingers between the heat shield and the core tank. In addition, after confirming the contact of the heat shield, the pressing state when attaching the heat shield is the same as the previous time, so the contact state does not change significantly, there is no difference in trend, and it is reattached. The situation can be prevented. As a result, the heat shield can be safely and easily attached to the core tank.

  Further, in the heat shield mounting device of the present invention, the pressing jig has a male screw portion formed on a peripheral surface of the shaft member, and the moving member has a central portion of a handle with respect to the male screw portion. An internal thread portion to be engaged is formed.

  According to this heat shield attachment device, the moving member is slid along the extending direction of the shaft member by rotating the handle. As a result, the effect of easily attaching the heat shield to the core tank can be obtained remarkably.

  Further, in the heat shield attachment device of the present invention, the pressing jig is provided with a grip handle centered on the shaft member at an extending end portion of the shaft member when attached to the bolt hole. It is characterized by being.

  According to this heat shield attachment device, the shaft member can be easily attached to the bolt hole by rotating the grip handle. As a result, the effect of easily attaching the heat shield to the core tank can be obtained remarkably.

  In the heat shield attachment device of the present invention, the pressing jig is mounted so as to be movable in the extending direction with respect to the shaft member, and includes a pressing ring that comes into contact with the moving member and the heat shield. It is characterized by having.

  According to this heat shield mounting device, the pressing ring functions as a spacer between the moving member and the heat shield, so that the moving member is prevented from coming into contact with the heat shield, and the direction toward the direction other than the slide movement direction is prevented. Transmission of unnecessary load to the heat shield due to movement of the moving member can be avoided.

  Moreover, in the heat shield attachment apparatus of this invention, it is arrange | positioned between the said heat shield side and the crane side, and is provided with the hanging jig | tool with which the recessed part was formed in the side part.

  According to this heat shield mounting device, since the heat shield is suspended by the crane in a form that avoids the flange at the upper end of the core tank by the concave portion, the heat shield can be suspended along with the outer surface of the core tank. It is possible to improve the workability of attaching the heat shield to the outer surface of the core tank.

  Further, in the heat shield attachment device of the present invention, the heat shield attachment device is inserted and fitted into a fitting hole provided so as to penetrate through the heat shield, and with respect to the attachment hole provided on the outer surface of the core tank. A positioning pin inserted and fitted is provided.

  According to this thermal shield mounting apparatus, the thermal shield is positioned and attached to the core tank by the positioning pins inserted and fitted into the fitting holes of the thermal shield and the mounting holes of the core tank. As a result, the state in which the heat shield is pressed against the core tank by the pressing jig can be positioned, and the heat shield can be attached to the core tank in this positioned state.

  In order to achieve the above-mentioned object, the thermal shield mounting method of the present invention is a thermal shield mounting method for mounting a thermal shield on the outer surface of a reactor core tank disposed in a reactor vessel. The rod-shaped shaft member is inserted into the insertion hole provided in the thermal shield, and the bolt hole provided in the outer surface of the core tank extends outward from the outer surface of the core tank. A step of attaching a shaft member; and a step of pressing the heat shield against the reactor core side by sliding a moving member provided to be engaged with the shaft member along the extending direction of the shaft member; , Including.

  According to this heat shield attachment method, the heat shield in which the shaft member attached to the outer surface of the reactor core is inserted by sliding the moving member of the pressing jig along the extending direction of the shaft member. The body is pressed against the outer surface of the core tank by the moving member. For this reason, it is not necessary to require a large number of workers for the operation of pressing the heat shield against the core tank, and only one person is required. Moreover, since many workers are not required, it is possible to reduce the occurrence of an accident in which the workers pinch fingers between the heat shield and the core tank. In addition, after confirming the contact of the heat shield, the pressing state when attaching the heat shield is the same as the previous time, so the contact state does not change significantly, there is no difference in trend, and it is reattached. The situation can be prevented. As a result, the heat shield can be safely and easily attached to the core tank.

  Moreover, in the heat shield attachment method of the present invention, a hanging jig having a recess formed on a side portion is disposed between the heat shield side and the crane side, and the heat shield is suspended to perform the work. It is characterized by that.

  According to this heat shield mounting method, since the heat shield is suspended by the crane in a form that avoids the flange at the upper end of the core tank by the recess, it is possible to suspend the heat shield along the outer surface of the core tank. It is possible to improve the workability of attaching the heat shield to the outer surface of the core tank.

  Further, in the heat shield mounting method of the present invention, in the step of pressing the heat shield against the core tank side, the heat shield is pressed against the core tank side, and then the fitting provided on the heat shield A positioning pin is inserted and fitted into the hole, and the positioning pin is inserted into and fitted into a mounting hole provided on the outer surface of the reactor core.

  According to this heat shield mounting method, the heat shield is positioned and attached to the core tank by inserting the positioning pins into the fitting holes of the heat shield and the mounting holes of the core tank. As a result, the state in which the heat shield is pressed against the core tank by the pressing jig can be positioned, and the heat shield can be attached to the core tank in this positioned state.

  In order to achieve the above-described object, the core tank of the present invention is fixed by a connecting bolt in a state where the thermal shield is positioned by the positioning pin.

  According to this core tank, since the heat shield is positioned by the positioning pins, it is possible to obtain a core tank in which the heat shield is fixed in a state where the application is maintained.

  According to the present invention, the heat shield can be safely and easily attached to the core tank.

FIG. 1 is a longitudinal sectional view of a pressurized water reactor. FIG. 2 is a perspective view of a core tank in a pressurized water reactor. FIG. 3 is an explanatory diagram of the heat shield attachment device and attachment method according to the embodiment of the present invention. FIG. 4 is a perspective view of the heat shield attached by the heat shield attachment device and the attachment method according to the embodiment of the present invention. FIG. 5 is a configuration diagram of a pressing jig in the heat shield mounting device according to the embodiment of the present invention. FIG. 6 is a configuration diagram of a temporary positioning pin in the heat shield mounting device according to the embodiment of the present invention. FIG. 7 is an explanatory diagram of an attachment method using a pressing jig of the thermal shield attachment device according to the embodiment of the present invention. FIG. 8 is an explanatory diagram of an attachment method using a pressing jig of the thermal shield attachment device according to the embodiment of the present invention. FIG. 9 is an explanatory diagram of an attachment method using a pressing jig of the thermal shield attachment device according to the embodiment of the present invention. FIG. 10 is an explanatory diagram of an attachment method using a temporary positioning pin of the thermal shield attachment device according to the embodiment of the present invention. FIG. 11 is an explanatory diagram of an attachment method using the positioning pins of the thermal shield attachment device according to the present embodiment.

  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.

  Although not shown, the nuclear power plant has a nuclear reactor and a steam generator arranged in a reactor containment vessel, and a steam turbine power generation facility. The nuclear reactor of the present embodiment uses light water as a reactor coolant and a neutron moderator, and produces 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.

  The nuclear reactor heats the primary cooling water by fuel fission, and the steam generator exchanges heat between the high-temperature and high-pressure primary cooling water and the secondary cooling water to generate high-pressure steam. The steam turbine power generation facility generates power by driving the steam turbine with the steam. On the other hand, the steam that has driven the steam turbine is cooled by a condenser to become condensate, and is returned to the steam generator.

  FIG. 1 is a longitudinal sectional view of a pressurized water reactor. In the pressurized water reactor of the nuclear power plant described above, as shown in FIG. 1, the reactor vessel 101 is a pressure vessel, and the reactor internal structure including the fuel assembly 120 can be accommodated therein. A reactor vessel lid 101b is fixed to the reactor vessel main body 101a by a plurality of stud bolts 121 and nuts 122. The reactor vessel main body 101a has a cylindrical shape in which an upper portion can be opened by removing the reactor vessel lid 101b and a lower portion is closed by a lower mirror 101e having a hemispherical shape.

  For the reactor internal structure, an upper core support plate 123 is disposed above the inlet side nozzle 101c and the outlet side nozzle 101d of the reactor vessel main body 101a, and a lower core support plate 124 is disposed near the lower mirror 101e below. Is done. The upper core support plate 123 and the lower core support plate 124 are disk-shaped and have many communication holes (not shown). The upper core support plate 123 is connected to the upper core plate 126 downward via a plurality of core support rods 125. The upper core plate 126 has a large number of communication holes (not shown). The upper core support plate 123 and a structure in which the upper core plate 126 is connected to the upper core support plate 123 via the core support rod 125 are referred to as an upper core structure.

  Further, for the reactor internal structure, a cylindrical reactor core 127 is disposed inside the reactor vessel main body 101a with a predetermined gap from the inner wall surface. The lower core support plate 124 is fixed to the lower end of the core tank 127. Further, the core tank 127 is provided with a lower core plate 128 below the inside thereof. The lower core plate 128 is disk-shaped and has a large number of communication holes (not shown), and is supported by the lower core support plate 124 via a plurality of lower core support columns 129. The core core 127, the lower core plate 128 provided for the core tank 127, and the lower core support plate 124 are referred to as a lower core structure. In the core tank 127 of the lower core structure, the upper core structure is inserted from above, and the upper core plate 126 is connected to the upper end. The lower core support plate 124 of the lower core structure is fixed to the reactor vessel main body 101a. That is, the lower core structure and the upper core structure are supported by the reactor vessel main body 101a via the lower core support plate 124.

  Further, a core 130 is formed by the upper core plate 126, the core tank 127, and the lower core plate 128 of the internal structure. In the core 130, a large number of fuel assemblies 120 are disposed inside the core tank 127 and loaded on the lower core plate 128. The core 130 has a large number of control rods 135 disposed therein. A large number of control rods 135 are combined at the upper end portion to form a control rod cluster 136 that can be inserted into the fuel assembly 120. The upper core support plate 123 is fixed with a large number of control rod cluster guide tubes 137 passing therethrough.

  The reactor vessel lid 101 b constituting the reactor vessel 101 is provided with a magnetic jack control rod drive device 138. The control rod driving device 138 is housed in a housing 139 that is integral with the reactor vessel lid 101b. The control rod cluster drive shaft 140 extending downward from the control rod drive device 138 extends through the control rod cluster guide tube 137 to the fuel assembly 120 so that the control rod cluster 136 can be gripped. It is done.

  Further, in the reactor vessel 101, the upper plenum 142 communicating with the outlet side nozzle 101 d is formed in the reactor core 127 and in the upper region of the upper core plate 126 with respect to the core 130 with the above-described configuration. On the other hand, a lower plenum 143 is formed outside the core tank 127 and below the lower core support plate 124. A downcomer portion 144 that communicates with the inlet side nozzle 101 c and the lower plenum 143 is formed between the inner wall of the reactor vessel 101 and the core tank 127.

  The reactor vessel main body 101a is provided with a number of instrumentation nozzles 145 that penetrate the lower mirror 101e. In each instrumentation nozzle 145, an in-core instrumentation guide tube 146 is connected to the upper end portion inside the furnace, and a conduit tube 147 is connected to the lower end portion outside the furnace. Each in-core instrumentation guide tube 146 has an upper end connected to the lower core support plate 124. Then, a thimble tube 148 equipped with a neutron flux detector (not shown) capable of measuring a neutron flux passes from the conduit tube 147 through the instrumentation nozzle 145 and the in-core instrumentation guide tube 146, and passes through the lower core plate 128. The fuel assembly 120 can be inserted through. Each in-core instrumentation guide tube 146 is provided with upper and lower connecting plates 150 and 151 for suppressing vibration. The connecting plates 150 and 151 are connected to the lower core support plate 124 through support columns 152. In addition, the connecting plates 150 and 151 are supported by a shock absorber 153. The shock absorber 153 is disposed between the bottom plate 154 fixed to the bottom of the lower mirror 101e and the lower connecting plate 151.

  FIG. 2 is a perspective view of a core tank in a pressurized water reactor.

  As shown in FIG. 2, the core tank 127 is assembled by welding a cylindrical upper core tank 127A and a lower core tank 127B. In the upper core tank 127A, a flange 127Aa to which the upper core support plate 123 of the upper core structure is connected is formed at the upper end thereof. The upper core tank 127A has an upper plenum 142 inside, and an outlet nozzle 127Ab leading to the outlet side nozzle 101d is formed. On the other hand, the lower core tank 127B has a lower core support plate 124 joined to the lower end thereof by welding. Further, the lower core tank 127B has a heat shield 161 fixed to the outer surface thereof by the main connection bolt 161A. Although this connection bolt 161A is not clearly shown in the drawing, for example, a groove is formed in the bolt head, and a rotation preventing member that is caulked and fitted in the groove is screwed together with the bolt head, so that the groove and the rotation preventing member Rotation is prevented by mutual fitting. The heat shield 161 is formed of, for example, stainless steel as an arc-shaped plate body along the cylindrical shape of the lower core tank 127B so as to cover the outer surface of the lower core tank 127B, and the lower core tank 127B and the reactor vessel It arrange | positions between the main bodies 101a. In this thermal shield 161, a part of the neutrons contained in the radiation of the fuel assembly 120 disposed in the core 130 inside the core tank 127 leaks outside the core tank 127 and collides with the reactor vessel body 101a. This prevents the deterioration of the reactor vessel main body 101a. The fuel assemblies 120 have a rectangular outer shape, and a plurality of fuel assemblies 120 are arranged based on the rectangular shape in the core 130. Therefore, the corner portions of the plurality of fuel assemblies 120 in which the maximum leakage of neutrons is arranged in the core 130 Therefore, the heat shield 161 is provided at a 45 ° position in the circumferential direction facing the corner portion.

  Hereinafter, the thermal shield attachment device and attachment method according to the present embodiment will be described. FIG. 3 is an explanatory diagram of the heat shield attachment device and attachment method according to the present embodiment.

  In order to attach the heat shield 161 to the reactor core 127, the reactor core 127 is set up on the work floor F in the same manner as in the reactor vessel 101 as shown in FIG. 3. Then, on the work floor F, the work platform 10 is arranged at a position on the side of the reactor core 127 and where the heat shield 161 is attached. In the work platform 10, a support 10 </ b> B is vertically provided on a base 10 </ b> A placed on the work floor F, and a scaffold 10 </ b> C is fixed at a desired height position of the support 10 </ b> B. The height position of the scaffold 10C can be adjusted. A plurality of scaffolds 10C are provided and arranged at a height suitable for each work.

  The eye shield 162 is attached to the upper end of the heat shield 161 attached to the reactor core 127, and is transported and attached to the reactor core 127 while being suspended by the crane 165 via the eye bolt 162. In the crane 165, for example, a hoisting machine 165B is movably provided along the horizontal rail 165A, and the heat shield 161 is suspended from a hook 165C that is lifted and lowered by the hoisting machine 165B.

  In the present embodiment, the hanging jig 1 constituting the heat shield mounting device is disposed between the hook 165C of the crane 165 and the eyebolt 162 of the heat shield 161. The hanging jig 1 extends in the vertical direction, and fixed arms 1B and 1C are integrally provided on the upper and lower portions of the main body 1A. The upper fixed arm 1B is connected to the hook 165C of the crane 165 via the chain 166, and the lower fixed arm 1C is connected to the eyebolt 162 of the heat shield 161 via the chain 167. The hanging jig 1 has a recess 1Aa formed on the side of the main body 1A. Recess 1Aa is formed by bending main body 1A into a U-shape. Although not shown in the drawing, the recess 1Aa may be formed by bending the main body 1A into a C shape or a square shape.

  The suspension jig 1 configured as described above is provided between the crane 165 and the heat shield 161, and when the heat shield 161 is suspended, the flange 127Aa of the core tank 127 (upper core tank 127A) is attached. It arrange | positions so that it may avoid by recessed part 1Aa. That is, since the core 127 is provided with the flange 127Aa and the heat shield 161 is attached to the outer surface directly below the core 127, when the heat shield 161 is directly suspended by the crane 165, the chain interferes with the flange 127Aa, and the heat It is difficult to suspend the shield 161 along the outer surface of the core tank 127, and the workability of attaching the heat shield 161 to the outer surface of the core tank 127 is poor.

  In this regard, in the present embodiment, a heat shield mounting apparatus including the hanging jig 1 that is disposed between the heat shield 161 side and the crane 165 side and in which the concave portion 1Aa is formed on the side portion is applied. The suspension jig 1 in which the concave portion 1Aa is formed on the side portion is disposed between the heat shield body 161 side and the crane 165 side, and the heat shield body attachment method for performing the work by hanging the heat shield body 161 is performed. .

  According to this heat shield attachment device and attachment method, since the heat shield 161 is suspended by the crane 165 in a form that avoids the flange 127Aa of the core tank 127 by the recess 1Aa, the heat shield 161 is attached to the outside of the core tank 127. It can be hung along the side surface, and the workability of attaching the heat shield 161 to the outer side surface of the core tank 127 can be improved.

  Although not clearly shown in the drawing, a horizontal rail and a lifting machine are provided on the work platform 10 at a position below the flange 127Aa to suspend the heat shield 161, or the work shield 10 is provided with the heat shield 161. A moving mechanism for supporting and moving in the horizontal direction may be provided, and the heat shield 161 can be suspended along the outer surface of the core tank 127, and the heat shield 161 can be hung on the outer surface of the core tank 127. The workability of attaching can be improved.

  FIG. 4 is a perspective view of the heat shield attached by the heat shield attachment device and the attachment method according to the embodiment of the present invention. FIG. 5 is a configuration diagram of a pressing jig in the heat shield mounting device according to the present embodiment. FIG. 6 is a configuration diagram of a temporary positioning pin in the heat shield mounting device according to the present embodiment. 7-9 is explanatory drawing of the attachment method using the pressing jig of the heat shield attachment apparatus which concerns on this embodiment. FIG. 10 is an explanatory diagram of an attachment method using the temporary positioning pins of the thermal shield attachment device according to the present embodiment. FIG. 11 is an explanatory diagram of an attachment method using the positioning pins of the thermal shield attachment device according to the present embodiment.

  Since the heat shield 161 is configured as an arc-shaped plate body along the cylindrical shape of the reactor core 127, the attachment surface of the heat shield 161 is pressed against the outer surface of the reactor core 127 for installation. After fixing the arc of the outer surface of 127 and the arc of the mounting surface of the heat shield 161, the connection bolt 161A (see FIG. 2) is used for fixing. Here, one of the heat shields 161 is about 700 kg, and a plurality of workers are required for the operation of pressing the heat shield 161 against the core tank 127.

  Further, as shown in FIG. 4, the heat shield 161 is provided with insertion holes 161 </ b> B penetrating on both side edges thereof. In the heat shield 161, the main connection bolt 161A and a temporary connection bolt 5 (see FIG. 9) described later are inserted into the insertion hole 161B, and the main connection bolt 161A and the temporary connection bolt 5 are tightened in the bolt hole 127Ba of the reactor core 127. As a result, the core tank 127 is fixed. In addition, the heat shield 161 is provided with a fitting hole 161C penetrating at a position between the insertion hole 161B in the center portion thereof. A temporary positioning pin 3 (see FIG. 6 and FIG. 10) and a final positioning pin 4 (see FIG. 11), which will be described later, are inserted into and fitted into the fitting hole 161C. Alternatively, the positioning pin 4 is inserted into the mounting hole 127Bd of the core tank 127 and fitted therein, thereby being positioned in the core tank 127.

  In the heat shield attachment device and attachment method of the present embodiment, the pressing jig 2 is applied. As shown in FIG. 5, the pressing jig 2 includes a shaft member 2A, a moving member 2B, and a pressing ring 2C.

  The shaft member 2A is a long body formed in a rod shape, and is inserted into an insertion hole 161B provided through the heat shield 161 as shown in FIGS. The shaft member 2A has a threaded portion 2Aa formed at one end thereof, and the threaded portion 2Aa is tightened against a bolt hole 127Ba provided on the outer surface of the reactor core tank 127 so that the outer side surface of the reactor core tank 127 is outside. It is attached to extend. The shaft member 2A is provided with a grip handle 2Ab at the other end. The grip handle 2Ab has a circular shape that is fixed around the shaft member 2A. When the grip handle 2Ab is gripped and rotated by an operator, the screw portion 2Aa of the shaft member 2A is bolted to the reactor core 127. The hole 127Ba can be tightened. The insertion hole 161 </ b> B provided so as to penetrate the heat shield 161 also serves as a hole for inserting the main connection bolt 161 </ b> A for attaching the heat shield 161 to the reactor core tank 127 and the temporary connection bolt 5. Further, the bolt hole 127Ba provided on the outer surface of the reactor core tank 127 also serves as a bolt to which the main connection bolt 161A and the temporary connection bolt 5 are tightened. The core tank 127 is provided with a ring-shaped support member 127Bb on the outer surface thereof and on the opening portion of the bolt hole 127Ba. The support member 127Bb positions and supports the heat shield 161 by contacting the heat shield 161.

  The moving member 2B is provided so as to be engageable with the shaft member 2A. Specifically, the moving member 2B is formed in a cylindrical shape by forming a female screw portion 2Ba that engages with a male screw portion 2Ac provided on a substantially entire peripheral surface of the shaft member 2A except for one end portion. ing. This moving member 2B has a female screw portion 2Ba formed at the center of a circular handle 2Bb. The moving member 2B slides and moves along the extending direction of the shaft member 2A due to the engagement between the male screw portion 2Ac and the female screw portion 2Ba when the operator grasps the handle 2Bb and rotates it.

  The pressing ring 2C is formed in a cylindrical shape so as to be attached to the male screw portion 2Ac of the shaft member 2A so as to be movable in the extending direction of the shaft member 2A. The pressing ring 2C comes into contact with the moving member 2B and the heat shield 161 by the movement of the shaft member 2A in the extending direction.

  Further, in the heat shield attachment device and the attachment method of the present embodiment, the temporary positioning pin 3 and the main positioning pin 4 as positioning pins are applied. As illustrated in FIG. 6, the temporary positioning pin 3 is formed in a rod shape and includes an insertion portion 3 </ b> A and a grip portion 3 </ b> D.

  The insertion portion 3A is formed in a rod shape. As shown in FIG. 10, the insertion portion 3A is inserted and fitted into a fitting hole 161C provided through the heat shield 161 and a mounting hole 127Bd provided on the outer surface of the reactor core 127. Is done.

  The grip portion 3D is a portion that extends from the end of the insertion portion 3A and is gripped by an operator. Further, the grip portion 3D is provided with a through hole 3Da that intersects (orthogonally) the extending direction. The through hole 3Da is for inserting a rod-shaped tool (not shown) into the fitting hole 161C and the mounting hole 127Bd of the insertion portion 3A.

  As shown in FIG. 11, the positioning pin 4 is formed in a rod shape and penetrates the heat shield 161 into which the temporary positioning pin 3 is inserted and fitted instead of the temporary positioning pin 3 described above. The fitting hole 161C provided and the mounting hole 127Bd provided on the outer surface of the reactor core 127 are inserted and fitted.

  The heat shield mounting method to which the pressing jig 2 and the positioning pin (temporary positioning pin 3 and main positioning pin 4) of such a heat shield mounting device are applied is as follows (1) to (12). Includes procedures.

(1) The pressing jig 2 is inserted into one of the insertion holes 161B of the heat shield 161 and tightened into the bolt hole 127Ba of the reactor core tank 127 (see FIG. 7).
(2) The handle 2Bb is rotated, the moving member 2B is slid in the extending direction of the shaft member 2A, and is brought into contact with the heat shield 161 via the pressing ring 2C (see FIG. 8). Further, the handle 2Bb is rotated to press the heat shield 161 toward the outer surface of the core tank 127 (see FIG. 9).
(3) When the heat shield 161 is pressed toward the outer surface of the core tank 127, the temporary connection bolt 5 is inserted into the insertion hole 161B of the heat shield 161, and the temporary connection bolt 5 is connected to the bolt hole 127Ba of the core tank 127. In contrast, the heat shield 161 is temporarily fixed as a manual tightening degree (see FIG. 9).
(4) Almost simultaneously with (3), the positioning pin (temporary positioning pin 3) is inserted into the fitting hole 161C of the heat shield 161 and the mounting hole 127Bd of the reactor core 127 (see FIG. 10).
(5) Remove the pressing jig 2 and tighten the temporary connection bolt 5 with torque management.
(6) The arc of the outer side surface of the core tank 127 and the arc of the mounting surface of the heat shield 161 are taken.
(7) The positioning pin (temporary positioning pin 3) and the temporary connection bolt 5 are removed, and the heat shield 161 is removed from the reactor core 127 in the reverse procedure described above.
(8) Confirmation and adjustment of hitting (repeat (1) to (8) until hitting).
(9) After completion of the application, (1) to (5) are performed, the pressing jig 2 is removed, and the temporary connection bolt 5 is torque-controlled and tightened.
(10) The positioning pin (temporary positioning pin 3) is removed, and the positioning pin (main positioning pin 4) is cooled and fitted there (see FIG. 11).
(11) After cold fitting, the positioning pin (main positioning pin 4) is non-rotatably welded (see FIG. 11).
(12) The temporary connection bolt 5 is removed, and instead of the temporary connection bolt 5, the final connection bolt 161 </ b> A is finally tightened by axial force tightening.

  As described above, the thermal shield mounting apparatus of the present embodiment is a thermal shield mounting apparatus for mounting the thermal shield 161 to the outer surface of the reactor core tank 127 arranged in the reactor vessel 101. And inserted into an insertion hole 161B provided through the heat shield 161 and extends outward from the outer surface of the reactor core 127 with respect to the bolt hole 127Ba provided on the outer surface of the reactor core 127. A pressing jig 2 having a rod-shaped shaft member 2A attached thereto and a moving member 2B provided so as to be able to engage with the shaft member 2A and slidably movable along the extending direction of the shaft member 2A. Is provided.

  According to this heat shield attachment device, the shaft member 2A attached to the outer surface of the core tank 127 is inserted by sliding the moving member 2B of the pressing jig 2 along the extending direction of the shaft member 2A. The heat shield 161 is pressed against the outer surface of the reactor core 127 by the moving member 2B. For this reason, it is not necessary to require many workers for the operation of pressing the heat shield 161 against the core tank 127, and one person is sufficient. Moreover, since many workers are not required, it is possible to reduce the occurrence of an accident in which the workers pinch fingers between the heat shield 161 and the core tank 127. In addition, after confirming the contact of the heat shield 161, the pressing state when attaching the heat shield 161 is the same as the previous time, so the hit state does not change greatly, and there is no difference in the trend. It is possible to prevent the situation from being redone. As a result, the heat shield 161 can be attached to the core tank 127 safely and easily.

  In the heat shield attachment device of the present embodiment, the pressing jig 2 has a male screw portion 2Ac formed on the peripheral surface of the shaft member 2A, and the male screw portion 2Ac at the center of the handle 2Bb in the moving member 2B. A female screw portion 2Ba is formed to engage with the screw.

  According to this thermal shield mounting apparatus, the movable member 2B is slid along the extending direction of the shaft member 2A by rotating the handle 2Bb. As a result, the effect of easily attaching the heat shield 161 to the core tank 127 can be significantly obtained.

  Further, in the heat shield attachment device of the present embodiment, the pressing jig 2 is centered on the shaft member 2A at the extending end (the other end) of the shaft member 2A when attached to the bolt hole 127Ba. A grip handle 2Ab is provided.

  According to this thermal shield attachment device, the shaft member 2A can be easily attached to the bolt hole 127Ba by rotating the grip handle 2Ab. As a result, the effect of easily attaching the heat shield 161 to the core tank 127 can be significantly obtained.

  Further, in the heat shield mounting device of the present embodiment, the pressing jig 2 is mounted so as to be movable in the extending direction with respect to the shaft member 2A, and is pressed against the moving member 2B and the heat shield 161. 2C.

  According to this heat shield mounting device, the pressing ring 2C functions as a spacer between the moving member 2B and the heat shield 161, so that the moving member 2B is prevented from coming into contact with the heat shield 161, and the sliding movement direction Transmission of an unnecessary load to the heat shield 161 due to the movement of the moving member 2B in a direction other than the above can be avoided.

  Further, in the heat shield attachment device of the present embodiment, the heat shield 161 is inserted and fitted into the fitting hole 161 </ b> C provided through the heat shield 161, and the attachment hole 127 </ b> Bd provided on the outer surface of the reactor core 127. Are provided with a temporary positioning pin 3 and a final positioning pin 4 as positioning pins to be inserted and fitted.

  According to this heat shield mounting device, the temporary positioning pin 3 and the main positioning pin 4 as positioning pins inserted and fitted into the fitting holes 161C of the thermal shield 161 and the mounting holes 127Bd of the reactor core 127. Thus, the heat shield 161 is positioned and attached to the core tank 127. As a result, the state where the heat shield 161 is pressed against the core tank 127 by the pressing jig 2 can be positioned, and the heat shield 161 can be attached to the core tank 127 in this positioned state.

  Further, the heat shield mounting method of the present embodiment is a heat shield mounting method for mounting the heat shield 161 to the outer surface of the reactor core tank 127 arranged in the reactor vessel 101, The rod-shaped shaft member 2A is inserted into the insertion hole 161B provided in the body 161, and the shaft extends so as to extend outward from the outer surface of the core tank 127 with respect to the bolt hole 127Ba provided in the outer surface of the core tank 127. A step of attaching the member 2A, and a step of pressing the heat shield 161 toward the reactor core 127 by sliding the moving member 2B provided to be engaged with the shaft member 2A along the extending direction of the shaft member 2A. And including.

  According to this heat shield attachment method, the shaft member 2A attached to the outer surface of the core tank 127 is inserted by sliding the moving member 2B of the pressing jig 2 along the extending direction of the shaft member 2A. The heat shield 161 is pressed against the outer surface of the reactor core 127 by the moving member 2B. For this reason, it is not necessary to require many workers for the operation of pressing the heat shield 161 against the core tank 127, and one person is sufficient. Moreover, since many workers are not required, it is possible to reduce the occurrence of an accident in which the workers pinch fingers between the heat shield 161 and the core tank 127. In addition, after confirming the contact of the heat shield 161, the pressing state when attaching the heat shield 161 is the same as the previous time, so the hit state does not change greatly, and there is no difference in the trend. It is possible to prevent the situation from being redone. As a result, the heat shield 161 can be attached to the core tank 127 safely and easily.

  Further, in the heat shield attachment method of the present embodiment, in the step of pressing the heat shield 161 against the core tank 127 side, the heat shield 161 is pressed against the core tank 127 side, and then the fitting provided on the heat shield 161. The temporary positioning pins 3 and the final positioning pins 4 as positioning pins are inserted and fitted into the fitting holes 161C and the mounting holes 127Bd provided on the outer surface of the reactor core 127.

  According to this heat shield mounting method, the temporary positioning pin 3 and the main positioning pin 4 as positioning pins are inserted into the fitting holes 161C of the heat shielding body 161 and the mounting holes 127Bd of the core tank 127. By combining, the heat shield 161 is positioned and attached to the core tank 127. As a result, the state where the heat shield 161 is pressed against the core tank 127 by the pressing jig 2 can be positioned, and the heat shield 161 can be attached to the core tank 127 in this positioned state.

  Further, the core tank 127 of the present embodiment is fixed by a connection bolt (main connection bolt 161A) in a state where the heat shield 161 is positioned by the position determination pin (main position determination pin 4).

  According to this core tank 127, since the heat shield 161 is positioned by the positioning pin (main positioning pin 4), the core tank 127 to which the heat shield 161 is fixed in a state where the application is maintained. Can be obtained.

DESCRIPTION OF SYMBOLS 1 Hanging jig | tool 1A Main-body part 1Aa Recessed part 1B Fixed arm 1C Fixed arm 2 Pushing jig 2A Shaft member 2Aa Screw part 2Ab Grasp handle 2Ac Male thread part 2B Moving member 2Ba Female thread part 2Bb Handle 2C Pushing ring 3 Temporary positioning pin (Positioning pin)
3A Insertion part 3D Grasping part 3Da Through hole 4 Positioning pin (Positioning pin)
5 Temporary connection bolt 101 Reactor vessel 127 Core tank 127A Upper core tank 127Aa Flange 127B Lower core tank 127Ba Bolt hole 127Bb Support member 127Bd Mounting hole 161 Heat shield 161A Main connection bolt 161B Insertion hole 161 C Fitting hole 16

Claims (10)

A heat shield attachment device for attaching a heat shield to an outer surface of a reactor core tank disposed in a nuclear reactor vessel,
A rod-like shape that is inserted into an insertion hole provided through the thermal shield and extends outward from the outer surface of the core tank to a bolt hole provided in the outer surface of the core tank. A shaft member of
A moving member provided so as to be engageable with the shaft member and slidable along an extending direction of the shaft member;
A heat shield mounting device comprising a pressing jig having   In the pressing jig, a male screw part is formed on the peripheral surface of the shaft member, and a female screw part that engages with the male screw part is formed in the center part of the handle in the moving member. The heat shield mounting apparatus according to claim 1.   The gripping handle centering on the shaft member is provided at the extending end of the shaft member when the pressing jig is attached to the bolt hole. The thermal shield mounting apparatus described.   The said pressing jig is mounted | worn with the said shaft member so that a movement to an extension direction is possible, and has a pressing ring contact | abutted to the said moving member and the said heat shield. The heat shield mounting apparatus according to any one of the above.   The heat shield attachment according to any one of claims 1 to 4, further comprising a hanging jig disposed between the heat shield side and the crane side and having a recess formed in a side portion. apparatus.   A positioning pin is provided which is inserted and fitted into a fitting hole provided through the thermal shield and is inserted into and fitted into a mounting hole provided on an outer surface of the reactor core. The thermal shield attachment device according to any one of claims 1 to 5. A heat shield attachment method for attaching a heat shield to an outer surface of a core tank disposed in a reactor vessel,
A rod-shaped shaft member is inserted into an insertion hole provided in the thermal shield, and the shaft extends so as to extend outward from the outer surface of the core tank with respect to a bolt hole provided in the outer surface of the core tank. Attaching the member;
A step of pressing the thermal shield against the reactor core side by sliding a moving member provided to be engaged with the shaft member along the extending direction of the shaft member;
A method for attaching a heat shield, comprising:   The heat according to claim 7, wherein a suspension jig having a recess formed on a side portion is disposed between the heat shield side and the crane side to suspend the heat shield and perform the work. Shield mounting method.   In the step of pressing the thermal shield against the reactor core side, the thermal shield is pressed against the reactor core side, and then provided in a fitting hole provided in the thermal shield and an outer surface of the reactor core tank. The heat shielding body mounting method according to claim 7 or 8, wherein a positioning pin is inserted and fitted into the mounting hole.   A core tank, wherein the thermal shield is fixed by a connecting bolt in a state where the thermal shield is positioned by a positioning pin.

Images