Limiting and guiding device for control rod assembly

Abstract

The utility model belongs to the technical field of nuclear power station refueling operation, and discloses a control rod assembly limiting and guiding device which is provided with a star-shaped frame guiding channel and a control rod bundle guiding channel which are communicated along a first direction, and the star-shaped frame guiding channel is communicated with the control rod bundle guiding channel. A limiting part is arranged on the star-shaped frame guide channel and extends from one end to the other end in the first direction on the control rod assembly limiting guide device; when the star-shaped frame moves in the star-shaped frame guide channel in the first direction, the limiting part limits the star-shaped frame in the direction perpendicular to the first direction. The star-shaped frame guiding channel is arranged, so that the star-shaped frame can extend into the star-shaped frame guiding channel, and meanwhile, the limiting part of the star-shaped frame guiding channel can abut against the star-shaped frame to carry out hard limiting on the star-shaped frame; the problems that the star-shaped frame shakes and is unstable in the process of controlling the rod bundle to be inserted finally and pulling out the fuel assembly at the beginning are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of refueling operation of nuclear power plants, and particularly relates to a control rod assembly limit guiding device. Background Art

[0002] A control rod assembly is an inner insert of a fuel assembly, which is evenly distributed in the core fuel. During the operation of the reactor, the control rod assembly is in a special working condition of high temperature, high pressure and high radioactivity, and defects such as wear, swelling and cracks may occur on its cladding. During each refueling overhaul, the control rod assemblies are inspected one by one, and in this process, the control rod assemblies need to be inserted / extracted from the fuel assemblies. The control rod assembly usually consists of a star-shaped frame and 24 control rod bundles, and the length of the assembly is about 4.6 meters. The lower end of the control rod bundle has a large degree of freedom. Therefore, it is difficult to ensure that the 24 control rod bundles are centered simultaneously during the process of inserting into the fuel assembly, resulting in bending deformation of the control rod bundles and damage to the bottom of the control rod bundles. At the same time, since the fuel grapple drives the fuel assembly to move up and down, and the fuel grapple is prone to jitter at the start-up and shutdown stages, the star-shaped frame is extremely prone to shaking during the two stages of the final insertion and the initial extraction of the control rod bundles from the fuel assembly, thus causing bending damage to the top of the control rod bundles and ultimately resulting in significant economic losses.

[0003] Currently, the commonly adopted method is to first set up a guiding frame, and then set several guiding plates distributed up and down on the guiding frame. The guiding plates are provided with star-shaped frame perforations and several guiding holes for limiting the control rod bundles. When the control rod bundles pass through the lower end of the guiding frame, since the guiding holes are aligned with the control rod bundle conduits in the fuel assembly, the control rod bundles can be accurately guided into the fuel assembly, avoiding bending deformation of the control rod bundles and damage to the bottom of the control rod bundles.

[0004] However, in the prior art, relying on the setting of the guiding frame and the guiding plates can only play a guiding role for the control rod bundles connected to the star-shaped frame. In reality, the phenomenon that the top of the control rod bundles is bent and damaged due to the easy shaking of the star-shaped frame during the two stages of the final insertion and the initial extraction of the control rod bundles from the fuel assembly still exists in large numbers. Therefore, in order to ensure that the control rod bundles do not bend and deform during the whole process of inserting / extracting from the fuel assembly, not only the problem of difficult centering of the control rod bundles and the fuel assembly needs to be solved, but more importantly, the stability problem of the star-shaped frame during the two stages of the final insertion and the initial extraction of the control rod bundles from the fuel assembly needs to be solved. Summary of the Utility Model

[0005] In view of the above situation, in order to overcome the defects of the prior art, the utility model provides a control rod assembly limit guiding device, which can guide and limit the star-shaped frame.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] The control rod assembly limiting and guiding device is used to limit and guide the star-shaped frame and the control rod bundle. The limiting and guiding device is provided with a star-shaped frame guiding channel and a control rod bundle guiding channel that penetrate along a first direction, and the star-shaped frame guiding channel and the control rod bundle guiding channel are connected and communicated. The star-shaped frame guiding channel is provided with a limiting portion, and the limiting portion extends from one end of the first direction to the other end on the limiting and guiding device. When the star-shaped frame moves along the first direction in the star-shaped frame guiding channel, the star-shaped frame can be limited in the direction perpendicular to the first direction.

[0008] Preferably, there are multiple control rod bundle guiding channels. The star-shaped frame guiding channel includes a star-shaped frame main channel, a star-shaped frame connecting channel, and a star-shaped frame intermediate channel that are respectively penetrated along the first direction;

[0009] The multiple control rod bundle guiding channels are divided into two groups;

[0010] In the control rod bundle guiding channels of the first group, each control rod bundle guiding channel is connected to the star-shaped frame guiding channel through a star-shaped frame connecting channel;

[0011] In the control rod bundle guiding channels of the second group, two control rod bundle guiding channels are a pair. In each pair of control rod bundle guiding channels, one side of one control rod bundle guiding channel is connected to the star-shaped frame guiding channel, and the other side is connected to the other control rod bundle guiding channel through the star-shaped frame intermediate channel.

[0012] Preferably, the limiting portion includes the inner wall of the star-shaped frame main channel and / or the inner wall of the star-shaped frame connecting channel and / or the inner wall of the star-shaped frame intermediate channel.

[0013] Preferably, the shape and size of the cross-section of the star-shaped frame guiding channel perpendicular to the first direction are the same as the shape and size of the perpendicular projection of the star-shaped frame.

[0014] Preferably, the control rod assembly limiting and guiding device is provided with a star-shaped frame guiding groove. The opening at one end of the star-shaped frame main channel is located at the bottom of the star-shaped frame guiding groove. Along the direction towards the star-shaped frame main channel, the groove wall surface of the star-shaped frame guiding groove gradually approaches the axis of the star-shaped frame main channel.

[0015] Preferably, the control rod assembly limiting and guiding device is provided with a control rod bundle guiding groove. The opening at one end of the control rod bundle guiding channel is located at the bottom of the control rod bundle guiding groove. Along the direction towards the control rod bundle guiding channel, the groove wall surface of the control rod bundle guiding groove gradually approaches the axis of the control rod bundle guiding channel.

[0016] Preferably, the control rod assembly limiting and guiding device is provided with an installation end face, and the installation end face is a plane.

[0017] Preferably, the installation end face is provided with a positioning boss.

[0018] Preferably, the control rod assembly limiting and guiding device includes a support plate and a support seat body connected to each other. The cross-sectional area of the support plate perpendicular to the first direction is larger than the cross-sectional area of the support seat body perpendicular to the first direction. The star-shaped frame guiding channel penetrates through the support plate and the support seat body, and the control rod bundle guiding channel penetrates through the support plate and the support seat body.

[0019] Preferably, the dimension of the star-shaped frame guiding channel in the first direction is not less than the length of the star-shaped frame.

[0020] Advantages of the present utility model:

[0021] The control rod assembly limiting and guiding device provided by the present utility model is provided with a star-shaped frame guiding channel and a control rod bundle guiding channel that penetrate along the first direction, and the star-shaped frame guiding channel and the control rod bundle guiding channel are communicated. During the process of finally inserting the control rod bundle into the fuel assembly, the star-shaped frame can extend into the star-shaped frame guiding channel. At the same time, since the star-shaped frame guiding channel is provided with a limiting portion, the limiting portion extends from one end to the other end of the control rod assembly limiting and guiding device in the first direction. When the star-shaped frame passes through the star-shaped frame guiding channel, the limiting portion can abut against the star-shaped frame, thereby performing hard limitation on the star-shaped frame, and further solving the problems of shaking and instability of the star-shaped frame in the two stages of finally inserting the control rod bundle and initially pulling out the fuel assembly. Description of the drawings

[0022] Figure 1 is a schematic structural view of the control rod assembly limiting and guiding device according to an embodiment of the present utility model;

[0023] Figure 2 is a top view of the control rod assembly limiting and guiding device according to an embodiment of the present utility model along the first direction;

[0024] Figure 3 is a bottom view of the control rod assembly limiting and guiding device according to an embodiment of the present utility model along the first direction;

[0025] Figure 4 is a front view of the control rod assembly limiting and guiding device according to an embodiment of the present utility model;

[0026] Figure 5 is a schematic structural view of the control rod bundle assembly according to an embodiment of the present utility model.

[0027] In the figure:

[0028] 1. Star - shaped frame guiding channel; 10. Limiting part; 11. Main channel of star - shaped frame; 12. Connecting channel of star - shaped frame; 13. Intermediate channel of star - shaped frame;

[0029] 2. Control rod bundle guiding channel;

[0030] 3. Control rod bundle guiding groove;

[0031] 4. Star - shaped frame guiding groove;

[0032] 5. Installation end face; 51. Positioning convex head;

[0033] 6. Support plate;

[0034] 7. Support seat body;

[0035] 100. Star - shaped frame;

[0036] 200. Control rod bundle. Detailed implementation manners

[0037] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar components or components with the same or similar functions from beginning to end. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present utility model, and should not be construed as a limitation to the present utility model.

[0038] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, a mechanical connection, an electrical connection, a direct connection, or an indirect connection through an intermediate medium. It can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0039] In the description of the present utility model, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first feature and the second feature, or may include that the first feature and the second feature are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "above and over", and "on the top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "below", "below and under", and "under the bottom of" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0040] The technical solution of the present utility model will be further described below in conjunction with the accompanying drawings and through specific embodiments.

[0041] As Figures 1 - 4 shown, the present utility model provides a limiting and guiding device for a control rod assembly, which is used for limiting and guiding Figure 5 the star-shaped frame 100 and the control rod bundle 200 as shown. The limiting and guiding device for the control rod assembly is provided with a star-shaped frame guiding channel 1 and a control rod bundle guiding channel 2 that penetrate along a first direction. The star-shaped frame guiding channel 1 communicates with the control rod bundle guiding channel 2. A limiting portion 10 is provided on the star-shaped frame guiding channel 1, and the limiting portion 10 extends from one end of the first direction to the other end on the limiting and guiding device for the control rod assembly. When the star-shaped frame 100 moves along the first direction in the star-shaped frame guiding channel 1, the limiting portion 10 abuts against the star-shaped frame 100 to limit the star-shaped frame 100 in the direction perpendicular to the first direction.

[0042] In the present utility model, by providing a star-shaped frame guiding channel 1 and a control rod bundle guiding channel 2 that penetrate along a first direction on the limiting and guiding device for the control rod assembly, and connecting the star-shaped frame guiding channel 1 and the control rod bundle guiding channel 2, during the process of the control rod bundle 200 finally being inserted into the fuel assembly, the star-shaped frame 100 can extend into the star-shaped frame guiding channel 1. At the same time, since the inner wall of the star-shaped frame guiding channel 1 includes the limiting portion 10, and the limiting portion 10 extends from one end of the first direction to the other end on the limiting and guiding device for the control rod assembly, when the star-shaped frame 100 passes through the star-shaped frame guiding channel 1, the limiting portion 10 can abut against the star-shaped frame 100 to perform hard limiting on the star-shaped frame 100, thereby solving the problems of shaking and instability of the star-shaped frame 100 during the two processes of the control rod bundle 200 finally being inserted into and initially being pulled out of the fuel assembly.

[0043] In this embodiment, the limiting portion 10 is a strip structure that extends along the first direction and is disposed in the star-shaped frame guiding channel 1. It can be a long strip-shaped wall surface or a long strip-shaped rib.

[0044] Specifically, as Figures 1 - 3As shown, a plurality of control rod cluster guide channels 2 are provided, and the star frame guide channel 1 includes a star frame main channel 11, a star frame connecting channel 12 and a star frame intermediate channel 13 which are respectively arranged to penetrate along the first direction. The control rod cluster guide channels 2 are divided into two groups. In the first group of control rod cluster guide channels 2, each control rod cluster guide channel 2 is connected to the star frame main channel 11 through a star frame connecting channel 12. The second group of control rod cluster guide channels 2 is a pair of two control rod cluster guide channels 2. In a pair of control rod cluster guide channels 2, one side of one control rod cluster guide channel 2 is connected to the star frame main channel 11, and the other side is connected to the other control rod cluster guide channel 2 through the star frame intermediate channel 13. On the basis of the star frame main channel 11, the star frame connecting channel 12 and the star frame intermediate channel 13 cooperate with each other to further enhance the stability of the star frame 100 moving in the control rod assembly limiting guide device. In this embodiment, 24 control rod cluster guide channels 2 are provided, 8 control rod cluster guide channels 2 are provided in the first group, so that 8 star frame connecting channels 12 are provided in the circumferential direction of the star frame main channel 11, and 8 control rod cluster guide channels 2 are provided in the second group, so that 8 star frame intermediate channels 13 are provided in the circumferential direction of the star frame main channel 11. The star frame connecting channels 12 and the star frame intermediate channels 13 are alternately provided in the circumferential direction of the star frame main channel 11.

[0045] More specifically, the limiting portion 10 includes an inner wall of the star frame connecting passage 12, and the limiting portion 10 extends from one end to the other end in the first direction in the control rod assembly limiting guide device. When the star frame 100 extends into the control rod assembly limiting guide device, the limiting portion 10 can be pressed against the star frame 100 from a direction perpendicular to the movement of the star frame 100 to limit the star frame 100, thereby further reducing the amplitude of the shaking of the star frame 100, thereby enhancing the stability of the movement of the star frame 100.

[0046] More specifically, the limiting portion 10 includes an inner wall of the middle channel 13 of the star frame. The limiting portion 10 also extends from one end to the other end in the first direction in the limiting guide device of the control rod assembly. When the star frame 100 extends into the limiting guide device of the control rod assembly, the limiting portion 10 can be pressed against the star frame 100 in a direction perpendicular to the movement of the star frame 100 to limit the star frame 100, so that the star frame 100 has stronger stability in moving in the limiting guide device of the control rod assembly.

[0047] More specifically, the shape and size of the cross section of the star frame guide channel 1 perpendicular to the first direction are the same as the shape and size of the vertical projection of the star frame 100. Since the outer contour of the inner wall of the star frame guide channel 1 matches the outer contour of the star frame 100, when the star frame 100 extends into the star frame guide channel 1, the inner wall of the star frame guide channel 1 can abut against the star frame 100, so that the star frame 100 does not shake, and the star frame 100 can move stably in the star frame guide channel 1.

[0048] Specifically, a star frame guiding groove 4 is further formed on the control rod assembly limiting and guiding device. One opening at one end of the main channel 11 of the star frame is located at the bottom of the star frame guiding groove 4. The groove wall surface of the star frame guiding groove 4 gradually approaches the axis of the main channel 11 of the star frame along the direction towards the main channel 11 of the star frame, so that during the process of finally inserting the control rod bundle 200 into the fuel assembly, the star frame 100 can also accurately and quickly extend into the star frame guiding channel 1 along the groove wall surface of the star frame guiding groove 4.

[0049] More specifically, a plurality of control rod bundle guiding grooves 3 are further formed on the control rod assembly limiting and guiding device. Each control rod bundle guiding groove 3 corresponds to a control rod bundle guiding channel 2. One opening at one end of the control rod bundle guiding channel 2 is located at the bottom of the control rod bundle guiding groove 3. The groove wall surface of the control rod bundle guiding groove 3 gradually approaches the axis of the control rod bundle guiding channel 2 along the direction towards the control rod bundle guiding channel 2, forming a flared shape, reducing the alignment difficulty of the control rod bundle 200, enabling the control rod bundle 200 to be quickly and accurately inserted into the control rod bundle guiding channel 2, and at the same time reducing the risk of bending of the control rod bundle 200, thereby facilitating the control rod bundle 200 to be guided into the guiding tube of the fuel assembly.

[0050] In this embodiment, the diameter of the control rod bundle 200 is 9.677 mm. Twenty-four control rod bundle guiding grooves 3 and twenty-four control rod bundle guiding channels 2 are formed on the control rod assembly limiting and guiding device. The twenty-four control rod bundle guiding grooves 3 are divided into two groups. Sixteen control rod bundle guiding grooves 3 of the first group are uniformly arranged along the edge of the control rod assembly limiting and guiding device. The height of each control rod bundle guiding groove 3 is 15 mm, and the maximum opening diameter is 38 mm. Eight control rod bundle guiding grooves 3 of the second group are provided, which are communicated with eight control rod bundle guiding grooves 3 in the first group through an intermediate channel 12, and are uniformly distributed on the top of the control rod assembly limiting and guiding device. And the height of each control rod bundle guiding groove 3 of the second group is 10 mm, and the maximum opening diameter is 18 mm.

[0051] Specifically, as Figures 3 - 4 shown, the installation end face 5 of the control rod assembly limiting and guiding device is set as a plane. The above setting enables the control rod assembly limiting and guiding device to be stably installed above the fuel assembly.

[0052] More specifically, a positioning convex head 51 is provided on the installation end face 5 to enable the control rod bundle guiding channel 2 to be aligned with the guiding tube of the fuel assembly.

[0053] In this embodiment, there are 4 positioning bosses 51 provided on the installation end face 5. There is a 1 mm chamfer on the vertical side around each positioning boss 51 and a 1 mm chamfer at the bottom. The position distribution of the 4 positioning bosses 51 matches the position distribution of the 4 water flow holes on the upper nozzle of the fuel assembly. The shape and size of the 4 positioning bosses 51 match the shape and size of the water flow holes of the fuel assembly, and the clearance between the 4 positioning bosses 51 and the 4 water flow holes on the upper nozzle of the fuel assembly is 0.2 mm. Thus, the control rod assembly limiting and guiding device can be accurately and stably fixed above the fuel assembly, and the control rod assembly limiting and guiding device does not shift relative to the fuel assembly. The control rod bundle guiding channel 2 can be precisely aligned with the guiding tube of the fuel assembly, improving the efficiency of inserting the control rod assembly into the fuel assembly, and at the same time avoiding the risk of the control rod bundle 200 being bent due to the misalignment of the control rod bundle guiding channel 2 with the guiding tube.

[0054] In other embodiments, the positioning boss 51 can also be set to one, with a rectangular cross-section or other structures. Correspondingly, there is a groove on the fuel assembly that matches the positioning boss 51, so that the positioning boss 51 can be inserted into this groove, and thus the control rod assembly can be accurately fixed on the fuel assembly.

[0055] Specifically, the control rod assembly limiting and guiding device includes a support plate 6 and a support seat body 7 that are connected to each other. The cross-sectional area of the support plate 6 perpendicular to the first direction is larger than the cross-sectional area of the support seat body 7 perpendicular to the first direction. Since the cross-sectional area of the support plate 6 perpendicular to the first direction is relatively large, the opening of the control rod bundle guiding groove 3 is not restricted by the volume of the control rod assembly limiting and guiding device, and the opening is more convenient. And because the setting of the support seat body 7 is not affected by the opening of the control rod bundle guiding groove 3, as long as it is ensured that the star-shaped frame 100 and the control rod bundle 200 can pass through the support seat body 7, the manufacturing cost of the control rod assembly limiting and guiding device is reduced. In this embodiment, the support plate 6 and the support seat body 7 are of an integral structure, with a simple structure, no loose parts, and can be manufactured by integral casting. The manufacturing process is simple and the cost is low.

[0056] Specifically, as Figure 1 shown, the size of the star-shaped frame guiding channel 1 in the first direction is not less than the length of the star-shaped frame 100, so as to ensure that the star-shaped frame 100 can completely extend into the star-shaped frame guiding channel 1, thereby realizing the full-process guiding and limiting of the movement of the star-shaped frame 100 by the control rod assembly limiting and guiding device during the process of the control rod bundle 200 finally inserting / initially pulling out of the fuel assembly.

[0057] More specifically, as Figures 1 - 3As shown, the shape and size of each control rod bundle guide channel 2 perpendicular to the first direction cross-section are the same as the shape and size of the perpendicular projection of each control rod bundle 200. This enables the control rod bundle 200 to just pass through the control rod bundle guide channel 2, improving the guiding accuracy of the control rod bundle guide channel 2 and the stability of the control rod bundle movement without affecting the descent of the control rod bundle 200.

[0058] In this embodiment, to protect the control rod bundle 200 and the fuel assembly from being worn, the overall control rod assembly limit guiding device is made of nylon 66 material.

[0059] In this embodiment, to facilitate the later decontamination and cleaning of the control rod assembly limit guiding device, the control rod assembly limit guiding device is set as the overall surface.

[0060] In this embodiment, the steps for the control rod assembly limit guiding device to assist the control rod assembly in inserting into the fuel assembly are as follows:

[0061] First, position the control rod assembly limit guiding device above the fuel assembly. After confirming the orientation, place it on the fuel assembly.

[0062] Then, lift the control rod assembly to be hoisted above the fuel assembly, and initially position the control rod bundle with the help of the control rod bundle guide groove 3 on the control rod assembly limit guiding device.

[0063] Then, lower the control rod assembly so that multiple control rod bundles 200 are aligned with the control rod bundle guide channels 2; then, continue to lower the control rod assembly, and the control rod bundles 200 are inserted into the guide tubes of the fuel assembly through the control rod bundle guide channels 2.

[0064] Next, the star-shaped frame 100 extends into the star-shaped frame guide channel 1 through the star-shaped frame guide groove 4.

[0065] Finally, close the fuel grapple, the control rod bundles 200 are released, and the star-shaped frame 100 is lifted away from above the fuel assembly.

[0066] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A control rod assembly limiting guide device, used for limiting and guiding a star frame (100) and a control rod bundle (200), characterized in that: The control rod assembly limiting guide device is provided with a star frame guide channel (1) and a control rod bundle guide channel (2) which are passed through in a first direction, and the star frame guide channel (1) and the control rod bundle guide channel (2) are connected. The star frame guide channel (1) is provided with a limiting portion (10), and the limiting portion (10) extends from one end to the other end of the first direction on the limiting guide device, and is used for limiting the star frame (100) in a direction perpendicular to the first direction when the star frame (100) moves in the star frame guide channel (1) along the first direction.

2. The control rod assembly limiting guide device according to claim 1, characterized in that: The control rod cluster guide channels (2) are provided in plurality, and the star frame guide channel (1) comprises a star frame main channel (11), a star frame connecting channel (12) and a star frame intermediate channel (13) which are respectively provided through the first direction; The plurality of control rod cluster guide channels (2) are divided into two groups; In the control rod cluster guide channels (2) of the first group, each control rod cluster guide channel (2) is connected to the star frame guide channel (1) through one of the star frame connecting channels (12); In the control rod cluster guide channels (2) of the second group, two control rod cluster guide channels (2) form a pair, and in each pair of control rod cluster guide channels (2), one side of one control rod cluster guide channel (2) is connected to the star frame guide channel (1), and the other side is connected to the other control rod cluster guide channel (2) through the star frame middle channel (13).

3. The control rod assembly limiting guide device according to claim 2, characterized in that: The limiting portion (10) comprises an inner wall of the star frame main channel (11) and / or an inner wall of the star frame connecting channel (12) and / or an inner wall of the star frame intermediate channel (13).

4. The control rod assembly limiting guide device according to claim 3, characterized in that: The shape and size of the cross section of the star frame guide channel (1) perpendicular to the first direction are the same as the shape and size of the vertical projection of the star frame (100).

5. The control rod assembly limiting guide device according to claim 2, characterized in that: The control rod assembly limiting guide device is provided with a star frame guide groove (4), an opening at one end of the star frame main channel (11) is located at the groove bottom of the star frame guide groove (4), and along the direction toward the star frame main channel (11), the groove wall surface of the star frame guide groove (4) gradually approaches the axis of the star frame main channel (11).

6. The control rod assembly limiting guide device according to claim 1, characterized in that: The control rod assembly limiting guide device is provided with a control rod bundle guide groove (3), an opening at one end of the control rod bundle guide channel (2) is located at the groove bottom of the control rod bundle guide groove (3), and along the direction toward the control rod bundle guide channel (2), the groove wall surface of the control rod bundle guide groove (3) gradually approaches the axis of the control rod bundle guide channel (2).

7. The control rod assembly limiting guide device according to claim 1, characterized in that: The control rod assembly limiting guide device is provided with a mounting end surface (5), and the mounting end surface (5) is a plane.

8. The control rod assembly limiting guide device according to claim 7, characterized in that: The mounting end surface (5) is provided with a positioning protrusion (51).

9. The control rod assembly limiting guide device according to claim 1, characterized in that: The control rod assembly limiting guide device comprises a support plate (6) and a support seat body (7) connected to each other, the cross-sectional area of ​​the support plate (6) perpendicular to the first direction is larger than the cross-sectional area of ​​the support seat body (7) perpendicular to the first direction, the star frame guide channel (1) passes through the support plate (6) and the support seat body (7), and the control rod bundle guide channel (2) passes through the support plate (6) and the support seat body (7).

10. The control rod assembly limiting guide device according to any one of claims 1 to 9, characterized in that: The dimension of the star frame guide channel (1) in the first direction is not less than the length of the star frame (100).

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