JP2011027657A - Clamping device for jet pump measurement piping - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate the installation of a clamping device for jet pump measurement piping mounted in a reactor pressure vessel of a boiling water reactor in a narrow space where interferences such as tie rods and riser pipes, for example, are located. <P>SOLUTION: The clamping device is equipped with: a C-shaped arm 30 in contact with the outer surface of a diffuser 13 of a jet pump; a body 31 mounted at one end of the arm 30; a pressing member 35 held by the body 31 so that it can be positioned and put into contact with; and a clamping bolt 34 located so as to displace the pressing member 35 relatively to the body 31. In the clamping device, moving elements are downsized, and especially their thickness is reduced by constituting the clamping device so that the pressing member 35 which has functions of fixing the clamping device onto the diffuser 13 and clamping the measurement piping 28, is displaced through the linear screw feeding toward the measurement piping 28 incidental to the revolution of the clamping bolt 34. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is attached to a measurement pipe for measuring the flow rate of a jet pump installed in a reactor pressure vessel (hereinafter referred to as RPV) of a boiling water reactor (hereinafter referred to as BWR). The present invention relates to a clamping device.

  A jet pump for supplying cooling water to the reactor core is installed in the BWR RPV. A plurality of jet pumps are arranged in a narrow annular space (hereinafter referred to as an annulus portion) between a core shroud (hereinafter referred to as a shroud) surrounding the core and an RPV.

  In the jet pump, a recirculation pump installed outside the RPV sucks the cooling water in the lower part of the annulus, boosts it, and sends it to a jet pump riser pipe (hereinafter referred to as riser pipe). The pressurized cooling water is ejected as a driving fluid through a nozzle attached to the upper portion of the riser pipe, and the cooling water in the annulus around the nozzle is drawn into the throat of the jet pump as a driven fluid by the ejection force.

  Cooling water made into the driving fluid and the driven fluid is mixed in the throat, passed through the diffuser of the jet pump, diffused, and supplied to the core through the lower plenum of the RPV.

  Jet pump measurement piping (hereinafter referred to as measurement piping) is connected to the upper and lower ends of the diffuser to transmit the pressure in the diffuser to a differential pressure gauge (not shown) provided outside the RPV to measure the flow rate. It will be installed. Such a measurement pipe is attached to the outer surface of the diffuser by, for example, welding via a measurement pipe support (hereinafter referred to as a support).

  The jet pump is used in a state where it is immersed in the flow of cooling water. Since a high-speed fluid flows inside, the jet pump is affected by fluid vibrations from the fluid inside and outside. The vibration due to the fluid vibration is transmitted to the measurement pipe. When the frequency of the fluid vibration matches the natural frequency of the measurement pipe, the measurement pipe resonates.

  Therefore, in order to reduce the influence of this resonance on the measurement pipe, a clamp device is attached to the measurement pipe from the outer surface side of the diffuser, and the measurement pipe is firmly restrained to reduce the generated stress of the measurement pipe (for example, , See Patent Documents 1 to 3.) In recent years, a clamp device of a type has been installed that restrains the measurement pipe so that it does not shift even if the measurement pipe breaks by supporting the measurement pipe at three points with restraint from the diffuser side (for example, patents) See references 2 and 3.)

JP-A-9-90085 JP 2004-212336 A JP 2007-333431 A

  Interferences such as tie rods for reinforcing the shroud may be installed in the annulus portion in the RPV where the jet pump is installed. The clamp devices described in Patent Documents 1 to 3 employ a wedge for the tightening mechanism of the measurement pipe, and since the tightening bolt moves integrally with the wedge, In some cases, the size is large, and it may be impossible to mount due to interference with the interference.

  Moreover, when the said measurement piping is installed in the diffuser outer surface at the side close | similar to a riser pipe | tube, the lowest stage support which is one of the clamp apparatus attachment object locations is located under a riser pipe | tube. Therefore, it is not possible to directly tighten the clamping bolt of the clamping device from above as in the prior art. In addition, when setting the tightening device, since the distance between the clamp device and the riser pipe is narrow, it is difficult to set the type of device to be tightened from above.

  The present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a clamp device that is miniaturized so that it can be installed in a plant where installation and tightening space is limited due to the presence of interferences. is there.

  Basic means for achieving the object of the present invention includes a C-type arm, a body provided on the arm, and a hole provided through the body through an outer peripheral side and an inner peripheral side of the C-type. The body is provided with a contact member for the jet pump measuring pipe provided in the body so as to be movable in the direction of the outer peripheral side and the inner peripheral side of the C-type; A jet pump measuring pipe clamping device comprising: a fastening bolt that is screwed into a screw hole provided in a contact member and screw-feeds the contact member.

  According to such a configuration, the abutting member is linearly displaced toward the measurement pipe to be clamped with the rotation of the tightening bolt, but the mechanism for generating the displacement can be arranged on a horizontal straight line and movable. In a plant where installation and tightening space is limited due to the presence of interference because the tightening part of the tightening bolt is within the range of the vertical thickness of the body and the vertical thickness is reduced. Can be attached.

  In the jet pump measuring pipe clamping device of the present invention, the movement of the abutting member applied to the measuring pipe and the fastening bolt for screw-feeding the abutting member are arranged on a horizontal straight line, and the fastening portion of the fastening bolt is provided. Since it can be accommodated in the upper and lower thicknesses of the body of the clamp device, the dimension in the thickness direction is greatly reduced. In addition, since there is no head of the tightening bolt that is most likely to interfere with the conventional clamping device, there are no places that interfere with surrounding interference.

  As a result, according to the present invention, it is possible to provide a clamp device for a jet pump measurement pipe that can easily and reliably obtain the fixing of the jet pump measurement pipe in the RPV where the interference exists. The effect which prevents the damage of the measurement piping resulting from it can be exhibited reliably.

It is a top view which shows 1st embodiment of the clamp apparatus of the jet pump measurement piping by this invention. It is a front view of the clamp apparatus of FIG. It is the side view which looked at the body part of the clamp apparatus from the left. It is a perspective view of the member for pressing of the clamp apparatus of FIG. It is a perspective view of the clamping bolt of the clamp apparatus of FIG. It is a top view which shows 2nd embodiment of the clamp apparatus of the jet pump measurement piping by this invention. It is a front view of a clamp device. It is an AA cross section of FIG. FIG. 7 is a perspective view of the retaining member of FIG. 6. FIG. 6 is a perspective view of a tightening bolt that is screwed with a retaining member. It is sectional drawing which shows the structure inside a boiling water reactor. It is a front view of the jet pump part in a nuclear reactor pressure vessel. It is the B section enlarged view of FIG.

  A clamping device according to an embodiment of the present invention includes a jet pump that clamps a measurement pipe for measuring a flow rate attached via a support to a diffuser of a jet pump installed in an annular region between a reactor pressure vessel and a core shroud. Clamping device for measurement pipe, which is a C-shaped arm that contacts the outer surface of the diffuser, a body provided at one end of the arm, and is held by the body so that the position can be adjusted, and is in contact with the outer surface of the measurement pipe A pressing member as a contact member, and a tightening bolt arranged to displace the pressing member relative to the body are provided, and the tightening portion of the tightening bolt is accommodated within the range of the vertical thickness of the body. The clamp device is fixed to the diffuser, and the pressing member is measured by rotating the tightening bolt. Side linear feed screw displaced so devoted is member for pressing the measuring pipe, the pressing member exerts a function of clamping the measurement pipe.

  The tightening bolt is housed so that it can rotate inside the body, and the pressing member is screw-fed, but the tightening bolt itself does not retreat out of the body, and further remains within the range of the thickness of the body. Because the moving parts are downsized, especially the thickness is reduced, a clamp device can be installed and applied to the measurement pipe of a jet pump even in a reactor pressure vessel where installation and tightening space is limited due to the presence of interference. It becomes.

  In this way, the clamping mechanism of the clamping device has a structure in which the pressing member is linearly screw-driven by the rotation of the clamping bolt that is screwed to the pressing member that fixes the measurement pipe, so that the thickness direction As a result of the drastic reduction in the dimensions of the reactor and the elimination of interference with the interferer, it is possible to firmly fix the jet pump measurement piping of the nuclear power plant where the interferer exists, and to cool the reactor pressure vessel and the jet pump. Demonstrates the effect of preventing damage to measurement piping caused by water flow vibration.

  A first embodiment of the present invention will be described using a boiling water reactor as an example with reference to the drawings. FIG. 11 is a schematic cross-sectional view of a reactor pressure vessel (RPV) 1 for a boiling water reactor (BWR). The RPV 1 generally has a substantially cylindrical central body portion, its lower end is closed by a partially spherical bottom head 2, and its upper end is partially spherical and closed by a removable top head 3. .

  The shroud 4 generally has a cylindrical shape surrounding the core 5 in the RPV 1. The shroud 4 is supported by a shroud support structure 6. An annular space 7 is also formed between the cylindrical portion of the RPV 1 and the cylindrical shroud 4 and is also called an annulus portion 11 or a downcomer.

  The inlet nozzle 8 extends through the side wall of the RPV 1 and is coupled to the jet pump 9. The recirculation pump (not shown) sucks and pressurizes the cooling water in the RPV 1 so as to be drawn from the RPV 1, and the boosted cooling water is supplied from the inlet nozzle 8 to the riser pipe 19 and downward from the nozzle 10 in the inlet mixer 22. The cooling water in the annulus portion 11 is sucked in, and passes through the throat 12, the diffuser 13 and the lower plenum 14, and is circulated and supplied to the core 5.

  When the cooling water is circulated to the core 5 by the jet pump 9, the jet pump 9 also sucks and circulates the cooling water in the annulus portion 11, so that a larger amount of cooling water than the amount of cooling water drawn out of the RPV 1 by the recirculation pump is supplied. Can be supplied to the core. Furthermore, by controlling the flow rate of the core 5, the output can be controlled by utilizing the change in the reactivity due to the void effect (the effect that the density of the cooling water decreases due to the generation of bubbles and the reactivity of the reactor decreases). Is possible.

  Steam generated in the core 5 becomes superheated steam by the separator 15 and the dryer 16, and drives a turbine (not shown) through the main steam nozzle 17. On the other hand, the water separated by the separator 15 and the dryer 16 is mixed with the water returned to the nuclear reactor by a water supply system (not shown) in the annulus portion 11 and supplied again to the core 5 by the jet pump 9. Is done.

  FIG. 12 shows a front view of the jet pump, and the structure of the jet pump 9 will be described. In FIG. 12, 18 is a riser elbow, 19 is a riser tube, 20 is a transition piece, 21 is an elbow, 10 is a nozzle, 22 is an inlet mixer, 13 is a diffuser, 23 is a bracket, 24 is a support, 25 is a wedge, and 26 is a beam. , 27 is a riser brace.

  An enlarged view of part B in FIG. 12 is shown in FIG. Reference numeral 28 denotes a measurement pipe, and reference numeral 29 denotes a measurement pipe support (support). The measurement pipe 28 is installed to transmit the pressure in the diffuser 13 to a differential pressure gauge (not shown) provided outside the RPV 1 and measure the flow rate, and is attached to the diffuser 13 via the support 29 by welding, for example. It has been.

  FIG. 1 is a plan view of a clamping device according to a first embodiment of the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a part of a side view thereof. The clamp device includes a C-shaped arm 30, and a body 31 integrally formed with the C-shaped arm 30 is provided at one end of the arm 30. As shown in FIG. 1, the arm 30 is provided with protrusions 32 inward at two locations. The protrusions 32 come into contact with the outer surface of the diffuser 13, so that the arm 30 is connected to the diffuser 13. It is designed to be held accurately.

  Further, as shown in FIG. 2, suspension brackets 33 are provided on the upper surfaces of the arms 30 and the body 31. The suspension brackets 33 are opened in the same direction as the curvature of the arms 30. A hole 33a for passing the hanging rope is provided, and the rope passed through the hole 33a of the hanging bracket 33 can be prevented from interfering with the diffuser 13 when the clamp device is attached to the diffuser 13. .

  Next, as shown in FIGS. 1 and 3, the body 31 is provided with a groove 36 into which a pressing member 35 as a contact member is inserted, and a hole 37 through which a part of the tightening bolt 34 penetrates the body 31. It has been.

  As shown in FIG. 4, U-shaped projections 38 are formed on both sides of the pressing member 35. A pressing member 35 is attached to the body 31 so as to be horizontally movable so that the body 31 is sandwiched between the protruding end portions of the U-shaped protrusion 38 in the vertical direction. With such an attachment structure, the pressing member 35 is prevented from coming off from the body 31 in the vertical direction to prevent it from falling off.

  The tightening bolt 34 shown in FIG. 5 has a tightening portion 40 that is narrower than the threaded portion 39, and the surface forming the step 41 therebetween is in contact with the body 31, so that the load at the time of tightening is applied to the contact portion. It can be received. The tightening portion 40 that is the head of the tightening bolt 34 is rotatably inserted into the hole 37, so that the tightening bolt 34 and the body 31 are combined in a nested structure at the hole 37. With this combination, the fastening bolt 34 can be structured not to protrude outside the body 31 or to have a short protruding length. However, when attaching a nut (not shown) for preventing removal or turning, a dimension necessary for attaching the nut may be projected.

  The screw portion 39 of the fastening bolt 34 is coupled by being screwed into a screw hole 42 formed in the pressing member 35 shown in FIG. Therefore, by rotating the tightening bolt 34, the horizontal movement of the pressing member 35 can be achieved without moving the tightening bolt 34, and the horizontal position of the pressing member 35 can be adjusted. It becomes possible to do. At this time, the moving direction of the pressing member 35 is the longitudinal direction of the support 29.

  Further, since the screw hole 42 is out of the center of the U-shaped groove 43 provided in the pressing member 35, the screw feed stroke by the tightening bolt 34 can be increased. In addition, since the tightening direction is from the horizontal direction, the tightening can be performed even when an interference such as a riser pipe is present above the tightening portion.

  As shown in FIG. 1, the clamping device has a U-shaped groove 43 provided in the pressing member 35, with the pressing member 35 abutting on the outer surface of the measuring pipe 28 opposite to the diffuser 13. The measurement pipe 28 is engaged with the clamp apparatus main body, the measurement pipe 28, and the diffuser 13.

  At this time, as shown in FIG. 4, a notch 35 a is formed in an intermediate portion of the portion where the pressing member 35 is in contact with the measurement pipe 28, so that the measurement pipe 28 is bent. Also, the pressing member 35 can be contacted at two locations above and below the portion in contact with the measurement pipe 28.

  The tightening bolt 34 can be tightened by inserting and rotating a hexagon wrench into a hole 44 provided at the end of the tightening portion 40 that is the head of the tightening bolt 34. The hole 44 may have a shape in which two hexagonal holes are shifted and overlapped by 30 ° so that a hexagonal wrench can be easily inserted. Similarly, the tip of the hexagon wrench may be thinned to facilitate insertion. Further, a mechanism that changes the rotation direction by 90 °, for example, a bevel gear or the like, may be formed on the head of the tightening bolt 34 so that the tightening can be performed from above.

  The tightening bolt 34 may be prevented from coming off by inserting a disk-shaped nut, for example, by welding after inserting the head into the through hole 37 of the body. Further, the tightening bolt 34 may have a non-rotating mechanism, for example, a washer folding mechanism. This anti-rotation mechanism prevents the tightening bolt 34 from being loosened after the measurement pipe 28 is clamped by the clamp device.

  According to the first embodiment, since the direction and movement direction of the hole 37, the fastening bolt 34, and the pressing member are horizontal, the vertical thickness of the clamping device is reduced, and the movement associated with the operation of the clamping device. In order to reinforce the shroud, for example, in the annulus portion in the RPV in which the jet pump is installed without requiring a large vertical space for the space required for the installation and operation of the clamping device. Even if an interfering object such as a tie rod is installed, it is possible to avoid the fact that interference with the interfering object makes it impossible to mount and operate the clamp device. This can contribute to easy and reliable installation of the clamping device.

  FIGS. 6 to 10 show a clamping device according to a second embodiment of the present invention, FIG. 6 is a plan view thereof, FIG. 7 is a front view thereof, and FIG. 8 is a measurement thereof. FIG. 9 is a cross-sectional view (A-A cross section of FIG. 6) of the tightening portion of the pipe, FIG. 9 is a perspective view of the retaining member 45 employed in the clamping device, and FIG. 10 is the tightening employed in the clamping device. 3 is a perspective view of a bolt 50. FIG.

  In addition to the pressing member 35 of the first embodiment, the clamping device according to the second example is provided with a retaining member 45 that abuts from the side opposite to the tightening direction of the pressing member 35 as an abutting member. . The clamp device includes a C-shaped arm 46, and a body 47 is provided at one end of the arm 46. The pressing member 35 and its driving mechanism are the same as those shown in the first embodiment.

  Further, as shown in FIG. 6, the arm 46 is provided with projections 32 inwardly at two locations as in the first embodiment, and these projections 32 are formed in the diffuser 13 of the jet pump. The arm 46 is accurately held by the diffuser 13 by contacting the outer surface of the diffuser 13. Further, the function of the hanging bracket 33 is equivalent to that shown in the first embodiment.

  Next, in the body 47, in addition to the groove 36 into which the pressing member 35 is inserted and the hole 48 through which a part of the tightening bolt 34 penetrates the body 47, as in the first embodiment, the retaining member A groove 49 into which 45 is inserted and a hole 51 through which the fastening bolt 50 passes are provided.

  As shown in FIG. 6, the clamping device has a U-shaped groove 43 provided in the pressing member 35, with the pressing member 35 being in contact with the outer surface of the measuring pipe 28 opposite to the diffuser 13. When the measurement pipe 28 is engaged, the clamp device, the measurement pipe 28 and the diffuser 13 are integrated. Thereafter, the retaining member 45 is brought into contact with the outer surface of the measurement pipe 28 on the support 29 side, whereby the measurement pipe 28 is clamped so as to be supported at three points in two directions.

  A pressing member 35 and a holding member 45 are attached to the groove 36 and the groove 49 in FIG. U-shaped protrusions 38 are formed on both sides of the pressing member 35 and the retaining member 45. The pressing member 35 and the retaining member 45 are attached so as to be horizontally movable so that the body 47 is sandwiched between the protruding end portions of the protrusions 38. By attaching the pressing member 35 and the retaining member 45 to the body 47 in this way, it is possible to prevent the pressing member 35 and the retaining member 45 from falling off and at the same time to adjust the position by smooth horizontal movement. I have to.

  As in FIG. 4, the tightening bolt 34 shown in FIG. 10 has a tightening portion 40 that is narrower than the threaded portion 39, and the surface forming the step 41 therebetween is in contact with the body 47, so The load is received at the contact portion. Further, the tightening bolt 50 shown in FIG. 10 has a tightening portion 53 that is thicker than the threaded portion 52, and is a step portion corresponding to the difference in thickness. Is received at the contact portion between the fastening bolt 50 and the body 47.

  The heads which are the respective tightening portions 40 and 53 of both the tightening bolts 34 and 50 are rotatably inserted into the respective through holes 48 and 51 so that the tightening bolts 34 and 50 and the body 47 Are combined in a nested structure. With such a combined structure, the fastening bolts 34 and 50 can be prevented from projecting to the outside of the body 47, or the projecting length can be shortened.

  However, with respect to the tightening bolt 34, when a nut (not shown) for retaining and preventing rotation is attached, a dimension necessary for attaching the nut may be projected. Further, when the tightening bolt 50 is provided with a non-rotating collar, it may be projected by the dimension of the collar.

  The screw portions 39 and 52 of the tightening bolts 34 and 50 are screwed into and coupled to the screw holes 42 and the screw holes 54 formed in the pressing member 35 and the anti-holding member 45, respectively. Therefore, when the tightening bolts 34 and 50 are rotated, the pressing member 35 and the retaining member 45 are screwed and moved in the horizontal direction without moving the tightening bolts 34 and 50. At this time, the moving direction of the pressing member 35 and the retaining member 45 is the longitudinal direction of the support 29. Further, since the screw hole 42 is out of the center of the U-shaped groove 43 provided in the pressing member 35, the screw feed stroke by the tightening bolt 34 can be increased. In addition, since the tightening direction is from the horizontal direction, the tightening can be performed even when an interference such as a riser pipe is present above the tightening portion.

  As shown in FIG. 9, the tip of the retaining member 45 is divided into a bifurcated shape so as to sandwich the support 29 therebetween, thereby forming both tip portions 55 and 56. And these front-end | tip parts 55 and 56 have a structure which contact | connects the measurement piping 28. FIG.

  When the clamp device is attached, the upper surface of the lower end portion 56 is in contact with the lower surface of the measurement pipe support 29, whereby the entire clamp device is tapered of the diffuser 13, that is, the outer diameter decreases in the upward direction. It is possible to suppress floating while receiving vibration due to the influence.

  Both tightening bolts 34 and 50 are tightened by inserting and rotating a hexagon wrench into hexagonal holes 44 and 57 provided in the heads of both tightening bolts 34 and 50. Each of the holes 44 and 57 may have a shape in which two hexagonal holes are shifted and overlapped by 30 ° so that a hexagonal wrench can be easily inserted. Similarly, the tip of the hexagon wrench may be thinned to facilitate insertion. Further, by forming a mechanism for changing the rotation direction by 90 °, for example, a bevel gear, on the heads of the tightening bolts 34 and 50, it is possible to tighten from above.

  Although not shown, the tightening bolt 34 may be prevented from coming off by inserting a disk-like nut (not shown) by welding or the like after the head is inserted into the hole 37 of the body. Both fastening bolts 34 and 50 may have a detent mechanism, for example, a washer folding mechanism. This rotation stop mechanism prevents the tightening bolts 34 and 50 from being loosened after the measurement pipe 28 is clamped by the clamp device.

  From the above embodiments, the following is for applying a clamp device that easily and reliably suppresses vibration to the measurement pipe of the jet pump even in a narrow area in the vicinity of the jet pump in the reactor pressure vessel of the boiling water reactor. New technical matters can be proposed.

  That is, a first technical matter is that a jet pump that clamps a measurement pipe for flow rate measurement that is attached to a diffuser of a jet pump that is installed in an annular region between a reactor pressure vessel and a shroud via a support. In the measuring pipe clamping device, a C-shaped arm that comes into contact with the outer surface of the diffuser, a body provided at one end of the arm, and a pressing member that is held by the body so that the position can be adjusted and is in contact with the outer surface of the measuring pipe A pressing bolt having a function of fixing the clamping device to the diffuser and further clamping the measuring pipe, and a clamping bolt arranged to displace the pressing member and the pressing member relative to the body The member is configured to restrain the measurement pipe by linearly moving to the measurement pipe side as the tightening bolt rotates. It is.

  Similarly, the second technical matter is a clamp device for a jet pump measurement pipe including the first technical matter, and is held by the body so that the position can be adjusted, and the other end is brought into contact with the outer surface of the measurement pipe. A holding member is provided, and the holding member is configured to be clamped in a state where the measurement pipe is sandwiched by being brought into contact with an outer surface of the measurement pipe on the side opposite to the pressing member. It is characterized by that.

  Similarly, a third technical matter is characterized in that, in the clamp device for a jet pump measurement pipe including the second technical matter, a tip portion that contacts the lower surface of the support is provided on the retaining member. It is to do.

  Similarly, according to a fourth technical matter, in the clamp device for a jet pump measurement pipe including the first technical matter, a step portion where the cross-sectional area changes is provided in the tightening bolt, and the portion interferes with the body. It is characterized by receiving a load at the time of tightening.

  Similarly, the fifth technical matter is characterized in that, in the jet pump measuring pipe clamping device including the first technical matter, the tightening bolt and the body have a nested structure.

  Similarly, the sixth technical matter is a clamping device for a jet pump measurement pipe including the first technical matter, wherein the central axis of the tightening bolt is in contact with the measurement pipe of the pressing member. It is characterized by being off center.

  Similarly, the seventh technical matter is the rotation that converts the direction of transmission of the rotational force required for tightening to the tightening portion of the tightening bolt by 90 ° in the jet pump measuring pipe clamping device including the first technical matter. It is characterized by providing a force transmission mechanism.

  Similarly, the eighth technical matter is characterized in that, in the clamp device for a jet pump measurement pipe including the seventh technical matter, a friction train is employed as the rotational force transmission means of the rotational force transmission mechanism. It is to be.

  Similarly, the ninth technical matter is characterized in that a gear train is employed as the rotational force transmission means of the rotational force transmission mechanism in the clamp device for the jet pump measurement pipe including the seventh technical matter. That is.

  The present invention can be used as a technique for clamping a measurement pipe of a jet pump of a boiling water reactor.

DESCRIPTION OF SYMBOLS 1 Reactor pressure vessel 9 Jet pump 12 Throat 13 Diffuser 19 Riser pipe 22 Inlet mixer 28 Measuring piping 30, 46 Arm 31, 47 Body 32, 38 Protrusion 33 Suspension bracket 34, 50 Tightening bolt 35 Pressing member 35a Notch 36 , 43, 49 Grooves 37, 48, 51 Through holes 39, 52 Screw portions 40, 53 Tightening portion 41 Steps 42, 54 Screw holes 44, 57 Hole 45 Anti-lock member 55 Tip (upper side)
56 Tip (bottom)

Claims (6)

A C-shaped arm;
A body provided on the arm;
A hole penetrating the body from the outer peripheral side to the inner peripheral side of the C-type,
An abutting member to a jet pump measuring pipe provided in the body so as to be movable in the direction of the outer peripheral side and the inner peripheral side of the C-type;
A tightening bolt that is rotatably provided in the hole and a screw portion is screwed into a screw hole provided in the abutting member and screwing the abutting member;
Jet pump measuring pipe clamping device equipped with.   In Claim 1, it has a contact part with the above-mentioned body which receives the reaction force at the time of applying the above-mentioned contact member to the above-mentioned jet pump measurement piping in the part of the above-mentioned bolt which has come off from the above-mentioned screw part. A jet pump measuring piping clamping device.   3. The jet pump measuring pipe clamping device according to claim 1, wherein the abutting member includes the screw hole at a position deviated from a portion corresponding to the jet pump measuring pipe.   The jet pump measuring pipe clamping device according to any one of claims 1 to 3, wherein a hole into which a wrench can be inserted is provided at an end of the head of the tightening bolt.   5. The method according to claim 1, wherein the body includes a pair of holes provided in the body, the contact member, the screw holes, and the tightening bolts, A jet pump measuring pipe clamping device, wherein the jet pump measuring pipe can be positioned on opposite sides of the jet pump measuring pipe.   In Claim 5, the said abutting member arrange | positioned in the side close | similar to the said jet pump among a pair of said abutting members has a forked shape part which can pinch | interpose the support of the said jet pump measurement piping in an up-down direction. A jet pump measuring pipe clamping device characterized by

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