A reactor position indicator removal tool

Abstract

The application belongs to the technical field of nuclear power plant reactor maintenance, and particularly relates to a reactor position indicator dismounting tool. The tool comprises a transmission component, a hand wheel set, a support set and a lifting set. The transmission component comprises a lead screw. The support set is in a cylindrical structure, and a hole through the lead screw is formed in a support plate top plate at the top end of the support set. The hand wheel set is connected with the lead screw. The lower end of the lead screw is connected with the lifting set. The lifting set is fixedly connected with the conical surface of the shell of the reactor position indicator. The tool provides the required slow and continuous pulling force by adopting the thread rotation method, prevents the position indicator from bouncing, reduces the risk of equipment damage, and avoids using brute force to dismount the jammed position indicator.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of nuclear power plant reactor maintenance, and particularly relates to a reactor position indicator dismounting tool. BACKGROUND

[0002] The control rod drive mechanism on the upper assembly of a certain nuclear power plant reactor is composed of five parts: an electromagnet assembly, a pressure shell, a moving assembly, a drive rod, and a reactor position indicator. The reactor position indicator is used to monitor the position of the control rod step by step, and has multiple groups of sensing elements inside, with a single weight of 18 kg. The reactor position indicator is sealed with the moving assembly through an inverted flange, and the sealing element has six bolts, six nuts, six gaskets, two half rings, and a reinforced graphite gasket of Φ58*Φ53*4.5 mm. During the annual refueling maintenance, 103 reactor position indicators need to be removed using a cantilever crane. In previous overhauls, there have been stuck reactor position indicators.

[0003] When dismounting these reactor position indicators, the original removal method is that the worker gently knocks the head of the reactor position indicator with a copper rod, while the cantilever crane driver increases the lifting speed of the crane to forcibly remove the reactor position indicator. This method has many risks and adverse effects: there is a risk of damaging the flange of the reactor position indicator, the sealing surface of the moving assembly, and the threads of the fastening bolts when the reactor position indicator is lifted instantaneously, and there is an increase in the working time of the workers in a high environmental dose (0.1 mSv / h), thereby increasing the radiation dose of the workers; there is a risk of damaging the internal electronic components of the reactor position indicator. SUMMARY

[0004] The purpose of the present application is to provide a reactor position indicator dismounting tool to solve the problem of the risk of damaging the flange of the reactor position indicator, the sealing surface of the moving assembly, and the threads of the fastening bolts when the reactor position indicator is lifted instantaneously.

[0005] The technical solution for achieving the purpose of the present application is as follows:

[0006] The reactor position indicator dismounting tool provided by the embodiment of the present application comprises a transmission component, a handwheel set, a support set, and a lifting set.

[0007] The transmission component comprises a lead screw; the support set is in a cylindrical structure, and a hole through the lead screw is formed in the top plate of the support plate at the top end of the support set; the handwheel set is connected with the lead screw; and the lower end of the lead screw is connected with the lifting set.

[0008] The lifting set is fixedly connected with the conical surface of the shell of the reactor position indicator.

[0009] Optionally, the lifting kit comprises a lifting kit top plate, a lifting kit connecting column, a lifting kit claw fixing pin, a lifting kit base, a lifting kit claw moving slot and a lifting kit claw.

[0010] The lower end of the screw rod is fixed with a stop block; the center of the lifting kit top plate is provided with a through hole clamped on the stop block; the lifting kit connecting column has four columns evenly welded with the lifting kit top plate and the lifting kit base.

[0011] The center of the lifting kit base is provided with an installation through hole for the head of the reactor position indicator to pass through; the two sides of the lifting kit base are symmetrically provided with an "L"-shaped lifting kit claw moving slot penetrating through the lifting kit base to provide a moving channel for the lifting kit claw; the lifting kit claw fixing pin is used to fix the lifting kit claw to move in the lifting kit claw moving slot; the lifting kit claw is in a semicircular shape, and the inner side of the semicircle is a conical body used to cooperate with the conical surface of the shell.

[0012] Optionally, the outer side of the lifting kit claw is a square body, and the center of the square body is a fixing through hole used for the lifting kit claw fixing pin to pass through the lifting kit claw moving slot in the lifting kit base and welded with the head to form an integral whole.

[0013] Optionally, the lifting kit claw fixing pin is a cylindrical body composed of an upper part and a lower part, and the diameter of the upper part is smaller than that of the lower part.

[0014] Optionally, the lifting kit connecting column is a hollow cylindrical column.

[0015] Optionally, the support kit comprises a support plate top plate, a support frame connecting column and a support frame base.

[0016] The support frame connecting column has four columns evenly welded with the support plate top plate and the support frame base at symmetric positions of four corners.

[0017] The through hole in the center of the top of the support frame base is used to make the flange of the reactor position indicator pass through smoothly; and the lower part of the support frame base is a hollow circular arc step to establish a support connection with the single hole in the upper plate of the upper part assembly.

[0018] Optionally, the support frame connecting column is a hollow cylindrical pipe.

[0019] Optionally, the hand wheel kit comprises a hand wheel and a hand wheel center sleeve.

[0020] The hand wheel is a hollow circular ring structure welded with the hand wheel center sleeve; the outer part of the hand wheel center sleeve is welded with the hand wheel through a hollow cylindrical pipe, and the inner structure is a cylindrical threaded hole which is connected with the screw rod of the transmission component through threads.

[0021] The beneficial technical effects of the present application are that:

[0022] (1) The reactor position indicator dismounting tool provided by the embodiment of the present application reduces the burden on the staff, improves the work efficiency of the reactor position indicator dismounting, shortens the work period of the dismounting work on the reactor maintenance main line, and reduces the total collective dose value of the reactor position indicator dismounting work;

[0023] (2) The reactor position indicator dismounting tool provided by the embodiment of the present application is light and flexible, the main structure is selected to be a hollow cylindrical structure, the weight of the complete tool is reduced to the maximum on the basis of meeting the overall structural strength, and the operator is facilitated to observe and install and use conveniently;

[0024] (3) The reactor position indicator dismounting tool provided by the embodiment of the present application adopts a threaded cooperation mode to provide reliable connection between the hand wheel set and the lifting set, and the lifting set and the adjustment of the position of the reactor position indicator clamping can be conveniently and flexibly adjusted according to the on-site demand;

[0025] (4) The reactor position indicator dismounting tool provided by the embodiment of the present application establishes reliable connection between the dismounting tool and the reactor position indicator body through the movement of the lifting set pawl in the pawl moving groove;

[0026] (5) The reactor position indicator dismounting tool provided by the embodiment of the present application greatly reduces the risk of damage to the position indicator sealing surface, the moving assembly head sealing surface and the internal elements of the position indicator, avoids the occurrence of abnormal events of the reactor position indicator dismounting work difficulty, and eliminates the direct economic loss caused by the replacement of spare parts. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 FIG. 1 is a structural schematic view of a reactor position indicator dismounting tool provided by the embodiment of the present application;

[0028] Figure 2 FIG. 2 is another structural schematic view of a reactor position indicator dismounting tool provided by the embodiment of the present application.

[0029] In the drawings:

[0030] 1 - reactor position indicator; 2 - shell cone surface; 3 - moving assembly; 4 - transmission component; 5 - hand wheel set; 6 - support set; 7 - lifting set; 8 - hand wheel center sleeve; 9 - hand wheel; 10 - support frame top plate; 11 - support frame connecting column; 12 - support frame base; 13 - lifting set top plate; 14 - lifting set connecting column; 15 - lifting set pawl fixing pin; 16 - lifting set base; 17 - lifting set pawl moving groove; 18 - lifting set pawl. DETAILED DESCRIPTION

[0031] In order for those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the following described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments described in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0032] In the description of the embodiments of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0033] In view of the defects and deficiencies of the reactor position indicator removal method, to reduce the burden of workers, improve the work efficiency of removing the reactor position indicator, reduce the occurrence of abnormalities in the work, and at the same time, to reduce the total collective dose value of the reactor position indicator removal work, the reactor position indicator removal tool provided in the embodiments of the present application uses the method of screw rotation to provide the required slow and continuous pulling force, prevents the position indicator from bouncing, reduces the risk of equipment damage, avoids using brute force to remove the stuck position indicator, realizes slow application of pulling force to the stuck position indicator, unfastens the seal between the reactor position indicator and the moving assembly, achieves safe and efficient removal of the stuck reactor position indicator, and eliminates the risks and adverse effects brought by the original method.

[0034] Based on the above, in order to clearly and specifically describe the above advantages of the present application, the specific embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0035] Referring to Figure 1 The figure is a structural schematic diagram of a reactor position indicator removal tool provided in the embodiments of the present application.

[0036] The reactor position indicator removal tool provided in the embodiments of the present application comprises a transmission component 4, a handwheel set 5, a support set 6 and a lifting set 7.

[0037] The transmission component 4 comprises a lead screw; the support set 6 is a cylindrical structure, and a hole through the lead screw is formed in the top plate 10 of the support plate at the top end of the support set 6; the handwheel set 5 is connected with the lead screw; and the lower end of the lead screw is connected with the lifting set 7.

[0038] The lifting kit 7 is fixedly connected with the shell taper surface 2 of the reactor position indicator 1.

[0039] In some possible implementation manners of the embodiment of the present application, the lifting kit 7 comprises a lifting kit top plate 13, a lifting kit connecting column 14, a lifting kit claw fixing pin 15, a lifting kit base 16, a lifting kit claw moving groove 17 and a lifting kit claw 18.

[0040] The lower end of the screw rod is fixed with a stop block; the center of the lifting kit top plate 13 is provided with a through hole, which is clamped on the stop block and connected with the lower cylindrical stop block of the transmission component 4 to transmit the pulling force; the lifting kit connecting column 14 has four columns, which are uniformly welded with the lifting kit top plate 13 and the lifting kit base 16 to form the overall frame structure of the lifting kit 7.

[0041] The center of the lifting kit base 16 is provided with a mounting through hole, which is used for the head of the reactor position indicator 1 to pass through; the lifting kit base 16 is symmetrically provided with an “L”-shaped lifting kit claw moving groove 17 on both sides, which penetrates the lifting kit base 16 to provide a moving channel for the lifting kit claw 18; the lifting kit claw fixing pin 15 is used for fixing the lifting kit claw 18 to move in the lifting kit claw moving groove 17; the lifting kit claw 18 is a semicircular body, and the inner side of the semicircle is a conical body, which is used for cooperation with the shell taper surface 2, as shown in Figure 2 .

[0042] It can be understood that the transmission component 4 provides the required slow and continuous pulling force for the whole position indicator dismounting process by the method of screw rotation. The transmission component 4 is integrally machined by the screw rod and the cylindrical stop block, wherein the stop block realizes stable and reliable connection with the lifting kit.

[0043] In one example, the outer side of the lifting kit claw 18 is a square body, and the center of the square body is a fixing through hole, which is used for the lifting kit claw fixing pin 15 to pass through the lifting kit claw moving groove 17 in the lifting kit base 16 and welded with the head to form an integral whole.

[0044] In another example, the lifting kit claw fixing pin 15 is a cylindrical body, which is composed of an upper part and a lower part, and the diameter of the upper part is smaller than that of the lower part.

[0045] In specific implementation, the lifting kit connecting column 14 can be a hollow cylindrical column.

[0046] In some possible implementation manners of the embodiment of the present application, the support kit 6 comprises a support plate top plate 10, a support frame connecting column 11 and a support frame base 12.

[0047] The four support frame connecting columns 11 are evenly welded to the symmetrical positions of the four corners of the support plate top plate 10 and the support frame base 12.

[0048] The through hole in the center of the top of the support frame base 12 is used to smoothly pass the reactor position indicator flange, and the lower part of the support frame base 12 is a hollow circular arc step, which is connected to the single hole in the upper plate of the upper assembly.

[0049] It can be understood that the support kit 6 is the main core support structure of the entire reactor position indicator removal tool, which is connected to the single hole in the upper plate of the upper assembly. The central through hole of the support plate top plate 10 provides a channel for the transmission component 4 to smoothly move up and down. The support frame connecting columns 11 are evenly welded to the symmetrical positions of the four corners of the support plate top plate 10 and the support frame base 12, forming the entire frame structure of the support kit 6.

[0050] In one example, the support frame connecting column 11 is a hollow cylindrical pipe.

[0051] In some possible implementations of the embodiments of the present application, the handwheel kit 5 includes a handwheel 9 and a handwheel center sleeve 8.

[0052] The handwheel 9 is a hollow ring structure, which is welded to the handwheel center sleeve 8 to form the entire handwheel kit. Its function is to change the radial force of the operator rotating the handwheel to axial force in the operating position.

[0053] The handwheel center sleeve 8 is welded to the handwheel 9 through a hollow pipe on the outside, and its internal structure is a cylindrical threaded hole. The threaded hole is connected to the lead screw of the transmission component 4 through threads, forming a stable upward force output mechanism.

[0054] In the following, a specific example is used to illustrate in detail the installation and use method of the reactor position indicator removal tool provided by the embodiments of the present application. The specific implementation is as follows:

[0055] (1) Move the lower cylindrical body of the lifting kit jaw fixing pin 15 in the two sides of the lifting kit 7 outward, move the lifting kit jaw 18 to the head position outside the lifting kit jaw moving groove 17, and move to the outside of the center hole of the lifting kit base 16.

[0056] (2) Lift the reactor position indicator efficient removal tool upward, so that the center hole of the support frame base 12 passes through the head flange of the reactor position indicator 1 and is installed in the single hole in the upper plate of the upper assembly.

[0057] (3) clockwise or counterclockwise rotation of the hand wheel 9 in the hand wheel assembly 5, through the hand wheel center sleeve 8 and the transmission component 4 screw thread cooperation, drive the lifting assembly 7 up and down movement, adjust to make the lifting assembly jaw 18 inside the cone and the reactor position indicator shell cone 2 position accurate centering;

[0058] (4) to the inside push lifting assembly 7 inside two sides of the lifting assembly jaw fixed pin 15 lower cylinder, make the lifting assembly jaw 18 along the lifting assembly jaw movement groove 17, move to with the reactor position indicator shell cone 2 fit, turn the lifting assembly jaw 18, make the lifting assembly 7 inside two sides of the lifting assembly jaw fixed pin 15 in the lifting assembly jaw movement groove 17 inside head position, under the action of upward pulling force, the jaw is in the limit not to open the reactor position indicator shell cone 2;

[0059] (5) counterclockwise rotation of the hand wheel 9 in the hand wheel assembly 5, through the hand wheel center sleeve 8 and the transmission component 4 screw thread cooperation, drive the lifting assembly 7 upward movement, until the reactor position indicator and the movement assembly seal is broken;

[0060] (6) after the seal is removed, turn the lifting assembly jaw 18 to the bottom, push the two sides of the lifting assembly jaw fixed pin 15 lower cylinder, make the lifting assembly jaw 18 to the lifting assembly jaw movement groove 17 outside the head position, until the lifting assembly base 16 center hole outside, and then lift the reactor position indicator efficient removal tool from the reactor position indicator.

[0061] The above detailed description of the present application is combined with the drawings and examples, but the present application is not limited to the above examples, within the knowledge of those skilled in the art, various changes can be made without departing from the purpose of the present application. The contents not described in detail in the present application can adopt the prior art.

Claims

1. A reactor position indicator removal tool, characterized in that: The tool comprises: a transmission component (4), a handwheel kit (5), a support kit (6) and a lifting kit (7); The transmission component (4) includes a screw rod (41); the support kit (6) is a cylindrical structure, and a hole for passing the screw rod (41) is provided on the support plate top plate (10) at the top of the support kit (6); the handwheel kit (5) is connected to the screw rod (41); and the lower end of the screw rod (41) is connected to the lifting kit (7); The lifting kit (7) is fixedly connected to the shell cone (2) of the reactor position indicator (1); A lifting kit (7) comprising: a lifting kit top plate (13), a lifting kit connecting column (14), a lifting kit claw fixing pin (15), a lifting kit base (16), a lifting kit claw moving groove (17) and a lifting kit claw (18); A stopper (42) is fixed on the lower end of the screw rod (41); a through hole is provided in the center of the top plate (13) of the lifting kit, which is clamped on the stopper (42); there are four connecting columns (14) of the lifting kit, which are evenly welded to the top plate (13) of the lifting kit and the base (16) of the lifting kit; A mounting through hole is provided in the center of the lifting kit base (16) for the head of the reactor position indicator (1) to pass through; an "L"-shaped lifting kit claw moving groove (17) is provided at symmetrical positions on both sides of the lifting kit base (16) and passes through the lifting kit base (16), providing a moving channel for the lifting kit claw (18); the lifting kit claw fixing pin (15) is used to fix the lifting kit claw (18) to move in the lifting kit claw moving groove (17); the lifting kit claw (18) is in the shape of a semicircle, with a total of two, and the inner side of the semicircle is a cone, which is used to cooperate with the conical surface (2) of the shell; Push the lower cylindrical bodies of the lifting kit claw fixing pins (15) on both sides of the lifting kit (7) inward, so that the lifting kit claws (18) move along the lifting kit claw moving grooves (17) to fit with the reactor position indicator shell conical surface (2), and rotate the lifting kit claws (18) so that the lifting kit claw fixing pins (15) on both sides of the lifting kit (7) are located at the inner head positions of the lifting kit claw moving grooves (17). Under the action of the upward pulling force, the claws are in a limited position so as not to be separated from the reactor position indicator shell conical surface (2).

2. The reactor position indicator removal tool according to claim 1, characterized in that: The outer side of the lifting kit claw (18) is a square body, and the center position of the square body part is a fixed through hole for the lifting kit claw fixing pin (15) to pass through the lifting kit claw moving groove (17) in the lifting kit base (16) and be welded to the head to form a whole.

3. The reactor position indicator removal tool according to claim 1, characterized in that: The lifting kit claw fixing pin (15) is a cylinder, which is composed of an upper and a lower part, and the diameter of the upper cylinder is smaller than the diameter of the lower cylinder.

4. The reactor position indicator removal tool according to claim 2, characterized in that: The lifting kit connecting column (14) is a hollow cylinder.

5. The reactor position indicator removal tool according to any one of claims 1 to 4, characterized in that: A support kit (6) comprising: a support plate top plate (10), a support frame connecting column (11), and a support frame base (12); There are four support frame connecting columns (11) in total, which are uniformly welded together at symmetrical positions of the four corners of the support plate top plate (10) and the support frame base (12); The through hole at the top center of the support frame base (12) is used to allow the reactor position indicator flange to pass smoothly; the lower part of the support frame base (12) is a hollow arc-shaped step, which establishes a supporting connection with the single hole on the upper plate of the upper component.

6. The reactor position indicator removal tool according to claim 5, characterized in that: The support frame connecting column (11) is a hollow cylindrical tube.

7. The reactor position indicator removal tool according to any one of claims 1 to 4, characterized in that: A handwheel kit (5), comprising a handwheel (9) and a handwheel center sleeve (8); The handwheel (9) is a hollow ring structure and is welded to the handwheel center sleeve (8); the outside of the handwheel center sleeve (8) is welded to the handwheel (9) through a hollow circular tube, and its internal structure is a cylindrical threaded hole, which is connected to the screw rod (41) of the transmission component (4) through a threaded connection.

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