KR100597727B1 - Locking device for the curved fuel assembly for the reactor - Google Patents

Abstract

The present invention relates to a device for stably securing a curved fuel assembly for a nuclear reactor inside a flow tube.

The present invention provides an upper fixing unit for positioning the curved fuel assembly in the center of the flow tube, a lower fixing unit for fixing the curved fuel assembly in the lower portion of the flow tube, and the curved fuel assembly in the inside of the flow tube. Provided is a fixture for a curved fuel assembly for a nuclear reactor comprising a desorption unit for separation. According to the present invention, the curved fuel assembly for a nuclear reactor can be easily loaded into a reactor core, and during the operation of the reactor, the vortex phenomenon of the inflow cooling water circulating in the core can be effectively prevented, thereby allowing the fuel assembly to be caused by fluid-induced vibration. An improved effect is obtained to suppress the upper transverse vibration and to effectively prevent the rotational movement of the fuel assembly which may be caused by the coolant flow, thereby achieving safe reactor operation.

Reactor, curved fuel assembly, fuel assembly fixture, reactor core, flow tube

Description

LOCKING DEVICE FOR THE CURVED FUEL ASSEMBLY FOR THE REACTOR}

1 is an exploded view showing a fixing device for a rod-shaped fuel assembly according to the prior art;

A), b) of FIG. 2 is a block diagram showing a fixing device for a rod-shaped fuel assembly according to the prior art, a) is a longitudinal cross-sectional view, b) is a cross-sectional view taken along the line A-A of FIG.

3 is an external perspective view of a state in which a flow tube is removed from a fixing device of a curved fuel assembly for a reactor according to the present invention;

4 is a longitudinal sectional view of the fixing device for the curved fuel assembly for a reactor according to the present invention;

5 is a cross-sectional view of a central rod provided in the fixing device for the curved fuel assembly for a reactor according to the present invention;

Figure 6 a), b), c) is a block diagram of a curved fuel assembly provided in the fixing device for the curved fuel assembly for a reactor according to the present invention,

         a) a plan view, b) a perspective perspective view, c) a sectional view taken along line B-B in FIG.

7 is a block diagram showing an upper fixing unit and a long detaching unit provided in the fixing device for the curved fuel assembly for a nuclear reactor according to the present invention;

8 is an external perspective view showing an upper guide cover provided in a fixing device for the curved fuel assembly for a nuclear reactor according to the present invention;

9 is a configuration diagram of the upper guide provided in the fixing device for the curved fuel assembly for a reactor according to the present invention,

         a) a perspective view of the appearance, b) a plan view, c) a detailed view of the leaf spring portion;

10 is a block diagram showing a lower fixing unit provided in the fixing device for the curved fuel assembly for a reactor according to the present invention;

11 is a block diagram showing the receptacle of the lower fixing unit provided in the fixing device for the curved fuel assembly for a reactor according to the present invention,

         a) a partially cut away perspective view, b) a longitudinal cross-sectional view;

12 is an external perspective view of a lower guide provided in a fixing device for the curved fuel assembly for a nuclear reactor according to the present invention;

13 is a detailed view of a spider provided in the fixing device for the curved fuel assembly for a reactor according to the present invention,

         a) is an appearance view, b) is a cutaway perspective view, c) is an operating state diagram;

14 is an external perspective view showing a central rod tip provided in the fixing device for the curved fuel assembly for a reactor according to the present invention;

15 is an external perspective view showing a linear flow guide member provided in the fixing device for the curved fuel assembly for a nuclear reactor according to the present invention;

FIG. 16 is a cross-sectional view showing a desorption unit provided in a fixing device for the curved fuel assembly for a reactor according to the present invention; FIG.

17 is a configuration diagram of the clasp head provided in the fixing device for the curved fuel assembly for a reactor according to the present invention,

         a) is a perspective view of the appearance, b) a partially cutaway perspective view;

18 is a configuration diagram of a spring cover provided in the fixing device for the curved fuel assembly for a reactor according to the present invention,

         a) is an external appearance perspective view, b) is a partially cutaway perspective view.

       <Description of Symbols for Main Parts of Drawings>

1 .... Fixture of curved fuel assembly for nuclear reactor according to the present invention

5 .... central rod 7 .... center rod tip

9 .... collar 9a .... collar pin

10 ... curved nuclear fuel assembly 12 .... curved nuclear fuel assembly

14 ... stiffener 16 .... spacer tube

30 .... Upper fixing unit 32 .... Upper guide cover

36 .... Extension 36a .... Concave groove

40 .... upper guide 44 .... wings

46 .... Incision 48 .... Elastic leaf spring

50 .... upper guide roller 60 .... lower fixing unit

62 .... receptacle 64a .... diameter reduction

64b ... upper conical plane 64c ... lower conical plane

70 .... Lower Guide 80 .... Spider

82 .... Space 84 .... Fixed Groove

90 ... linear guide element 100 ... flow tube

120 .... Detachable unit 122 .... grapple head

126 ... spring cover 130 ... spring

200 .... conventional fuel assembly 220 ... upper guide spring

230 ..... flow tube 232 .... receptacle

234 .... Spring 236 .... Center Rod Tip

240 .... The Spider 242 .... Home

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for stably securing a curved nuclear fuel assembly for a reactor inside a flow tube. More specifically, the curved nuclear fuel assembly for a nuclear reactor is easily loaded in a reactor core, and the reactor is in operation. It effectively prevents the vortex phenomena of the inflow coolant circulating in the core, thereby suppressing the upper lateral vibration of the fuel assembly due to fluid-induced vibration, and effectively preventing the rotational movement of the fuel assembly which may be caused by the coolant flow, thereby safe operation of the reactor An apparatus for fixing a curved fuel assembly for a nuclear reactor that has been improved to achieve this.

In general, a nuclear fuel assembly used in a nuclear reactor has a structure loaded in a flow tube of a cylindrical structure installed inside the reactor core, and has nuclear fuel and a supporting structure for supporting the nuclear fuel assembly. Fixtures for loading and securing the system.

1 is a view showing an example of a fuel assembly of a domestic reactor according to the prior art, the fuel assembly and the flow tube is separated.

2 a, b) is a cross-sectional view of the nuclear fuel assembly and the flow tube according to the prior art shown in FIG.

In the nuclear fuel assembly as described above, heat is generated together with neutrons in the nuclear fuel during operation of the reactor, and the heat is removed by the coolant, and the coolant is introduced into the lower part of the reactor core by a cooling pump (not shown). It has a flow system that absorbs heat via a fuel assembly loaded in a flow tube inside the core, and then circulates and discharges to the upper portion of the core and cools in the cooler.

As described above, in the process of removing the heat of the fuel assembly by the cooling water, there is a possibility that fluid induced vibration occurs in the fuel assembly and the flow tube by the flow of the cooling water passing through the inside of the flow tube. It is well known that such fluid-induced vibrations have a major adverse effect on the stable operation of the reactor.

Therefore, the main requirement for the lock assembly of the fuel assembly is to first be able to easily mount and detach the fuel assembly in the core, and to avoid the unwanted movement, in particular vibration, of the fuel assembly which may be caused by the coolant flow circulating inside the core. And rotational motion can be prevented.

That is, the fixing device of the fuel assembly should be designed to minimize the vibration of the fuel assembly due to the coolant flow, and should be structurally sound so that there is no possibility of destruction by fatigue or surrender.

Meanwhile, as shown in FIG. 1, the conventional nuclear fuel assembly 200 includes rod-shaped fuel, and the upper portion of the nuclear fuel assembly 200 has a linear guide to prevent shaking of the upper fuel assembly due to fluid-induced vibration. A top guide spring 220 is installed. In addition, a lower portion of the fuel assembly 200 is provided with a spring 234 and a center rod tip 236 required to fix it to the receptacle 232 of the flow tube 230.

Accordingly, when the fuel assembly 200 is mounted inside the flow tube 230, the central rod tip 236 of the fuel assembly 200 may be moved to the flow tube 230 as shown in FIG. 2B. When inserted into the groove 242 of the spider 240 provided in the lower receptacle 232, the spring 234 is compressed and at the same time by rotating the center rod tip 236 90 °, the center rod The tip 236 is fixed to the outer rim of the groove 242 of the spider 240 does not fall to the upper side.

In addition, the upper guide spring 220 installed on the conventional fuel assembly 200 is elastically bent at the inner side of the upper side of the flow tube 230, as shown in Figure 2a, nuclear fuel in the center of the flow tube 230 Three places are supported so that the aggregate 200 may be positioned.

The upper guide spring 220 has a linear structure, and when the nuclear fuel assembly 200 is loaded into the flow tube 230, the upper guide spring 220 makes point contact with the inner circumferential surface of the flow tube 230 by its elastic force. There was a problem in that the wear caused by friction at the contact portion of the guide spring 220 and the flow tube 230 is likely to occur.

In addition, the lower fixing mechanism for fixing the conventional fuel assembly 200 has a form of simply holding the center rod tip 236 into the groove 242 of the spider 240 to be elastically supported by the spring 234, so that There was a problem that the fuel assembly 200 can not effectively prevent the rotational movement in the circumferential direction inside the flow tube 230 by the flow.

In addition, in the conventional lower fixing mechanism as described above, a method of effectively blocking the turbulent flow phenomenon of the inflow cooling water is not devised, which causes the fluid-induced vibration in the fuel assembly 200, and makes the operation of the reactor unstable. It was to have a problem.

In order to solve the above-mentioned problems, the present invention securely fixes the curved fuel assembly for nuclear reactors to the core, and suppresses the lateral vibration of the upper fuel assembly caused by the fluid-induced vibration generated by the coolant circulating inside the core. In addition, the purpose of the present invention is to provide an improved fixing device for the curved fuel assembly for the nuclear reactor, which can prevent the rotational movement of the fuel assembly by effectively preventing the vortex flow of the cooling water flowing in the flow tube to achieve stable reactor operation.

In addition, the present invention is stably supported so that the fuel assembly is located in the center of the flow tube, the wear does not occur in the upper inner surface of the flow tube always support the fuel assembly in the correct state, the curved fuel assembly for the reactor to prevent damage to the accessories The purpose is to provide a fixing device.

In order to achieve the above technical problem, the present invention is a fixing device for a curved nuclear fuel assembly for a reactor for fixing the curved nuclear fuel for the reactor inside the flow tube,

An upper stationary unit configured to support a plurality of upper guide vanes fixed to an upper side of the curved fuel assembly on an inner surface of the flow tube to serve as an elastic plate spring, and to position the curved fuel assembly in the center of the flow tube;

The lower guide which is fixed to the lower side of the curved fuel assembly and fitted into the flow tube is provided with a plurality of wings of plate shape to impart rotational resistance to the circumferential rotation of the curved fuel assembly, and the spider located on the lower side of the lower guide A lower fixing unit fitting and fixing a central rod tip of the curved fuel assembly; And

It is fitted to the upper portion of the center rod of the curved fuel assembly, and provided with a spring that provides an elastic restoring force to be fixed to the groove of the center rod tip so that the curved fuel assembly is fixed and separated inside the flow tube It includes a desorption unit; to provide a fixing device for the curved fuel assembly for a nuclear reactor, characterized in that configured to prevent the vibration and rotational movement of the nuclear fuel assembly during the operation of the reactor, and to prevent damage to the components.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

3 is a configuration diagram of a curved fuel assembly to which a fixing device is applied according to an embodiment of the present invention, and FIG. 4 is a cross-sectional view of the curved fuel assembly mounted inside the flow tube.

Referring to FIG. 3, the fixing device 1 for the curved fuel assembly for a nuclear reactor according to the present invention includes an upper fixing unit 30 on an upper side of the curved fuel assembly 10 so that the curved fuel assembly 10 is a flow tube. When mounted in the interior of the 100, it is to be located in the center of the flow tube 100.

In addition, the present invention is provided with a lower fixing unit 60 on the lower side of the curved fuel assembly 10 to not only fix the curved fuel assembly 10 inside the lower portion of the flow tube 100, but also the curved fuel assembly 10. Is given by the cooling water to impart rotational resistance to rotation in the circumferential direction.

In addition, the present invention is provided with a spring 130 on the top of the center rod 5 of the curved fuel assembly 10, the curved fuel assembly 10 is a structure that allows the desorption in the interior of the flow tube (100). .

The curved fuel assembly 10 includes a central rod 5 as shown in FIG. 5, a curved fuel 12 as shown in FIG. 6, a stiffener 14, and A spacer tube 16 and the like.

The curved fuel assembly 10 has a long rod-shaped center rod 5, an upper end of the center rod 5 forms a male screw portion 5a, and a lower end of the curved nuclear fuel assembly 10 having protrusions 7a on both sides. The center rod tip 7 is formed. On the upper side of the center rod tip 7, a collar 9 having a large diameter is fixed by the collar pin 9a.

In addition, the curved rod fuel 12 as shown in FIG. 6 is inserted into the center rod 5, and the curved fuel 12 uses nuclear fuel composed of six curved plates having different radii of curvature. Each curved fuel fuel 12 is fixed by three support members 14 arranged at 120 ° intervals. As shown in FIG. 6C, the support members 14 extend and support along the length of the curved nuclear fuel 12.

The cooling water for removing heat generated from the nuclear fuel 12 flows into the space P between the curved nuclear fuel 12. The support member 14 is connected to the cylindrical gap holding member 16 located at the center of the curved fuel assembly 10. In addition, the gap retaining member 16 forms a hole 16a in the center thereof, and when the center rod 5 is fitted into the hole 16a, the gap holding member 16 is fitted with a tolerance of approximately 0.1 mm to allow the nuclear fuel assembly 10 to be inserted. It is configured to support it.

The curved fuel assembly 10 made as described above is fixed at the center through the upper fixing unit 30 when fitted into the flow tube 100.

In FIG. 7, the upper fixing unit 30 and the long detachable unit 120 are illustrated.

The upper fixing unit 30 includes an upper guide cover 32, an upper guide 40, and an upper guide roller 50.

When the coolant flows inside the fuel assembly 10, that is, between the curved fuel 12, in the state where the fuel assembly 10 is loaded in the reactor core, the fuel assembly may be caused by fluid-induced vibration. 10) will vibrate. Therefore, the upper fixing unit 30 of the curved fuel assembly 10 should have a function to effectively prevent this.

Therefore, the upper fixing unit 30 provided in the present invention is provided with an upper guide cover 32 on the upper side of the center rod 5, and on the lower side of the long detachable unit 120 to be described later, This forms a hole 34 in the center to be coupled to the central rod 5, as shown in FIG. 8, and the circumference of the curved nuclear fuel 12 in the same manner as the support member 14 of the fuel assembly 10. In the direction of 120 ° intervals.

The upper guide cover 32 serves to support the lower end of the spring 130 of the elongate detachment unit 120, which will be described later, for this purpose than the hole 34 through which the central rod 5 penetrates. A seating groove 34a having an enlarged diameter is formed on the upper surface. In addition, three concave grooves 36a are respectively provided in the lower portion of the extension part 36, and the upper edge 42 of the upper guide 40 positioned at the lower side thereof is fitted into the upper guide 42 by vibration. When the elastic plate spring portion 48 of 40 moves, it serves to guide in the radial direction of the flow tube (100).

Meanwhile, as illustrated in FIG. 9, the upper guide 40 includes wings 44 disposed at intervals of 120 ° in the circumferential direction of the curved nuclear fuel 12, and each of the wings 44 has an incision ( 46 is formed to form the elastic leaf springs 48, respectively, and the elastic leaf springs 48 are configured to absorb manufacturing tolerances and vibration energy.

In addition, the upper guide rollers 50 are rotatably mounted on the upper end of each of the elastic leaf springs 48, and the upper guide rollers 50 are loaded when the nuclear fuel assembly 10 is loaded inside the flow pipe 100. In order to support and support the inner surface of the flow tube 100 in three directions, the fuel assembly 10 is positioned at the center of the flow tube 100, and the inner surface of the flow tube 100 and the outer surface of the fuel assembly 10 directly. It prevents contact.

When the upper guide roller 50 moves up and down in contact with the inner circumferential surface of the flow tube 100, the upper guide roller 50 makes contact with the inner circumferential surface of the flow tube 100, thereby avoiding friction or abrasion so that the flow tube 100 or the upper portion is not present. There is no damage to the guide 40.

In addition, the wings 44 of the upper guide 40, as shown in Figure 9a, each of the concave grooves (44a) formed in the lower edge thereof, the support member 14 for supporting the curved nuclear fuel 12 The upper edges of the upper and lower sides respectively correspond to the inner side.

10 shows a lower fixing unit 60 for fixing the lower portion of the nuclear fuel assembly 10 in the fixing device 1 of the curved fuel assembly for nuclear reactors according to the embodiment of the present invention.

The lower fixing unit 60 is a receptacle 62 having a cylindrical structure fitted into the lower inner portion of the flow tube 100, a lower guide 70 fitted to the inside thereof, a spider 80, Including a linear flow guide member 90, the center rod tip (7) forming the lower end of the center rod (5) is fitted, the structure and function of the components are as follows.

The receptacle 62 has a cylindrical structure, as shown in FIGS. 11a) and b), and is fitted into the lower inside of the flow tube 100, or directly welded to the lower end thereof, as shown in FIG. 10. It is a structure that is connected to. The receptacle 62 has a diameter reducing portion 64a on its inner surface, and has an upper conical surface 64b and a lower cone surface 64c inclined toward the diameter reducing portion 64a on its upper and lower sides.

In addition, concave grooves 66 into which the lower guide 70 is described, respectively, are formed in the upper conical surface 64b, and a spider for fixing the center rod tip 7 to the diameter reduction portion 64a. 80 is disposed, and the straight flow guide member 90 is disposed on the lower conical surface 64c below the spider 80.

In addition, as shown in FIG. 12, the lower guide 70 inserted into the receptacle 62 is fixed with a hole 72 through which a central rod 5 penetrates, and a curved sheet. It is designed to have three wings 74 arranged at intervals of 120 ° coinciding with the direction of the support member 14 supporting the nuclear fuel 12.

In addition, the wings 74 of the lower guide 70 are formed with recessed grooves 74a in the upper surface thereof, respectively, and in the recessed grooves 74a, as shown in detail in FIG. 4, the support member 14. The bottom edge of the structure is fitted correspondingly. In addition, as shown in FIG. 10, the wing 74 of the lower guide 70 has a shape in which a middle outer edge thereof is fitted into three concave grooves 66 formed on the upper conical surface 64b of the receptacle 62. It is designed to prevent the lower guide 70 and the fuel assembly 10 connected thereto by the coolant flow in the circumferential direction of the flow pipe 100.

In addition, the lower guide 70 forms a concave step 78 whose length is shorter than the bottom edges of the three wings 74, which are center rods extending through the lower guide 70 to the lower end ( It is a space where the collar 9 fixed to 5) is located.

In addition, the receptacle 62 is provided with a spider 80 therein so as to load the nuclear fuel assembly 10, the spider 80 as shown in FIG. A space 82 through which the lower center rod tip 7 of the center rod 5 penetrates is formed, and both protrusions 7a of the center rod tip 7 are inserted inside the space 82. Once rotated, a fixing groove 84 is formed which is caught and prevented from being pulled out to the upper portion.

The spider 80 has three wings 86 aligned in the same direction as the wings 74 of the lower guide 70 when the fuel assembly 10 is loaded, and the respective wings 86 are receptacles 62. It is fixed by welding inside of it.

This spider 80 is arranged so that the wings 86 are in close contact with each of the three wings 74 of the lower guide 70, that is, the lower edges of the wings 74 of the lower guide 70 are subsequently connected to the spider. The upper edges of the wings 86 of 80 are welded to the receptacle 62 so that they are in close contact.

Meanwhile, as shown in FIG. 14, the center rod tip 7 coupled to the spider 80 as described above has protrusions 7a formed on both sides thereof, and the protrusions 7a are formed on the spider 80. The nuclear fuel assembly 10 is fixed to the axial direction when the nuclear fuel assembly 10 is mounted inside the flow tube 100 by being inserted into and fixed in the fixing groove 84.

In addition, the lower fixing unit 60 is provided with a straight flow guide member 90 on the lower side of the spider 80, which flows from the lower end of the flow tube 100, the space between the curved nuclear fuel 12 For imparting straightness to the cooling water flowing in (P), as shown in FIG. 15, it has three wings 92 corresponding to the wings 86 of the spider 80, the wings are receptacles ( Outer edges thereof are integrally connected to the lower conical surface 64c of 62 by welding or the like (see FIG. 11B).

As described above, the direction of the blade 92 of the linear flow guide member 90 is configured to coincide with the three blades 86 of the spider 80, so that the linear flow guide member 90 imparts straightness to the coolant to supply curved fuel. It is to improve the flow rate unevenness in the circumferential direction of cooling water which may occur at the inlet of (12) and to reduce the fluid induced vibration.

In addition, the present invention includes a desorption unit 120 to allow the curved fuel assembly 10 to be fixed and separated inside the flow tube 100.

As shown in FIG. 16, the demountable unit 120 includes a latch head 122, a spring cover 126, and a spring positioned on an upper portion of the center rod 5 to which the curved fuel assembly 10 is fitted. 130, etc. are included.

Then, the long mounting unit 120 is screwed to the upper end of the center rod (5) in the state in which the spring 130 and the spring cover 126 in the center rod (5), It is a structure fixed integrally by spot welding.

The clasp head 122 provided in the desorption unit 120 is for loading and detaching the nuclear fuel assembly 10 to the core, and after holding the clasp head 122 using a nuclear fuel loading mechanism (not shown) The assembly 10 can be moved up and down or rotated. This is shown in Figure 17a), b), there is formed a mounting groove 124a for connecting to the nuclear fuel loading mechanism (not shown), and screwed to the upper male portion 5a of the central rod (5) A female threaded portion 124b for forming is formed.

In addition, the spring cover 126 located on the lower side of the clasp head 122 forms a space 128 in which the spring 130 is installed, as shown in FIG. 18. Likewise fitted to the center rod (5) to support the top of the spring (130).

In addition, the spring 130 is fixed at the upper end by the space 128 of the spring cover 126, the lower end by the seating groove 34a of the upper guide cover 32, the fuel assembly 10 Inserting the central rod tip 7 into the spider 80 and pressing downward, the spring 130 is compressed, and in the state by rotating the central rod tip 7 by 90 °, the central rod tip 7 is It is caught in the fixing groove 84 of the spider 80.

At this time, the spring 130 pushes the upper guide cover 32 downward with respect to the clasp head 122 by its elastic restoring force, which is inserted into the central rod 5 through the upper guide 40. 10 so that the lower guide 70 is supported by the receptacle 62 coupled to the flow pipe 100 so that the fuel assembly 10 does not move in its axial direction, but moves or vibrates in the axial direction. Will be buffered and prevented.

Reference numeral 150 is a fastening means for fixing the flow tube 100 to the core of the reactor, it is a part that can be changed by screw fastening.

The fixing device 1 of the curved fuel assembly for a nuclear reactor assembly according to the present invention configured as described above may be achieved through the following procedure when the nuclear fuel assembly 10 is to be mounted inside the flow tube 100.

First, as the assembly process for the nuclear fuel assembly, when the lower guide 70 is inserted from the top onto the center rod 5 as shown in FIG. 5, the lower guide 70 has a lower end of the center rod 5. It is supported by a fixed collar 9. Then, the gap retaining member 16 of the nuclear fuel assembly 10 is inserted into the upper side thereof, and the upper guide 40 is inserted into the upper side thereof, and the upper guide cover 32 is fitted into the upper fixing unit 30. Let's do it.

Then, the spring 130 and the spring cover 126 are inserted into the center rod 5 to the upper side thereof, and the clasp head 122 is fixed to the upper end of the center rod 5.

In such a state using the nuclear fuel loading mechanism (not shown) to hold the clasp head 122, and inserted into the inside of the flow pipe 100, the outer edges of the lower guide 70 concave of the receptacle 62 Inserted to engage the grooves 66, the center rod tip 7 of the fuel assembly 10 is inserted into the spider 80 and pressed downward, the spring 130 is compressed, in that state the center rod When the tip 7 is rotated 90 ° in the fixing groove 84, the center rod tip 7 is caught in the fixing groove 84 of the spider 80.

In this process, since the spider 80 and the linear flow guide member 90 are fixed to the receptacle 62 by welding or the like, no separate assembly is necessary.

As described above, the fixing device 1 of the curved fuel assembly for a nuclear reactor according to the present invention has all three wings of the upper guide 40 provided in the upper fixing unit 30 to serve as an elastic plate spring, thereby stably maintaining the upper fuel assembly. Transverse shake and vibration can be suppressed.

In addition, the upper guide rollers 50 are in contact with the inner surface of the flow tube 100, not point contact, even if the displacement occurs in the axial direction inside the flow tube 100, so friction or wear is minimized to minimize the Prevent damage or breakage.

In addition, the present invention is introduced into the inner side from the lower end of the flow pipe 100 by engaging the three wings of the lower guide 70 in the lower fixing unit 60 and three concave grooves of the receptacle 62. It is designed to effectively prevent the axial rotational movement of the fuel assembly 10 due to the fluid induced vibration of the cooling water.

In addition, by forming three wings of the spider 80 in the lower fixing unit 60 and at the same time, three wings of the linear flow guide member 90 can be configured to suppress vortices, which are the main causes of fluid induced vibration, It can effectively introduce the laminar flow.

In addition, the nuclear fuel assembly 10 is arranged on the upper side of the desorption unit 120, the fuel assembly 10 through the spring 130 provided therein receptacle 62 of the lower fixing unit 60 It is possible to effectively fix and suppress the axial vibration of the fuel assembly 10 by being able to be fixed to).

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims. In particular, it is evident that the materials, simple shapes and dimensional changes of the component parts are all included within the scope of the present invention.

As described above, according to the present invention, the curved nuclear fuel assembly for nuclear reactors can be securely fixed to the core, and the lateral vibration of the upper fuel assembly caused by the fluid-induced vibration generated by the coolant circulating inside the core can be effectively suppressed.                     

In addition, by effectively preventing the vortex flow of the cooling water flowing in the flow tube, it is possible to prevent the rotational movement of the nuclear fuel assembly to achieve a stable reactor operation.

In addition, the present invention stably supports the fuel assembly to be located in the center of the flow tube, and minimizes abrasion at the upper inner surface of the flow tube so that the fuel assembly is always supported in the correct position and the damage to the accessories is obtained. will be.

Claims (14)

In the fixing device of the curved nuclear fuel assembly for the reactor for fixing the curved nuclear fuel fuel 12 for the reactor inside the flow tube 100, Wings of the plurality of upper guides 40 fixed to the upper side of the curved fuel assembly 10 are supported on the inner surface of the flow tube 100 to serve as elastic leaf springs, and the curved fuel assembly 10 is flow tube An upper fixing unit (30) adapted to be positioned at the center of the center (100); The lower guide 70, which is fixed to the lower side of the curved fuel assembly 10 and fitted to the flow tube 100, has a plurality of wings in the form of plates to impart rotational resistance to the circumferential rotation of the curved fuel assembly 10. And a lower fixing unit (60) having a spider (80) positioned at a lower side of the lower guide (70) to fit a central rod tip (7) of the curved fuel assembly (10); And A spring 130 inserted into an upper portion of the center rod 5 of the curved fuel assembly 10 and providing an elastic restoring force to fix the center rod tip 7 to a groove of the spider 80; And a demountable unit 120 which allows the curved fuel assembly 10 to be fixed and separated inside the flow tube 100 to prevent vibration and rotational movement of the nuclear fuel assembly during operation of the reactor, and to damage parts. Fixing device for the curved fuel assembly for a reactor, characterized in that configured to prevent. The upper fixing unit (30) according to claim 1, further comprising: an upper guide cover (32) on the upper side of the center rod (5) and on the lower side of the elongate detachable unit (120); An upper guide 40 formed at a lower side of the upper guide cover 32 to form a plurality of elastic leaf springs 48; And, The upper guide rollers 50 are rotatably mounted on the upper end of each of the elastic leaf springs 48 to be in contact with the inner circumferential surface of the flow tube 100 so that friction or wear is not generated. Fixing device for curved fuel assembly for nuclear reactors. According to claim 2, The upper guide cover 32 is formed in the upper surface of the mounting groove (34a) having a diameter larger than the hole 34 through which the center rod 5 penetrates the mounting unit 120 Supporting the lower end of the spring 130, three concave grooves (36a) are respectively installed in the lower portion of the extension portion 36, the upper edge 42 of the upper guide 40 located on the lower side is fitted When the wing of the upper guide (40) is moved by vibration, the fixing device of the curved nuclear fuel assembly for a reactor, characterized in that configured to guide in the radial direction of the flow tube (100). 3. The upper guide (40) according to claim 2, wherein the upper guide (40) includes wings (44) arranged at intervals of 120 [deg.] In the circumferential direction of the curved nuclear fuel (12), and the wings (44) each have an incision (46). Fixing device for a curved nuclear fuel assembly for a nuclear reactor, characterized in that configured to absorb the manufacturing tolerances and vibration energy by forming each of the elastic plate spring portion (48). 5. The curved fuel plate of claim 3, wherein the extension part 36 of the upper guide cover 32 and the blades 44 of the upper guide 40 are configured to coincide with each other. Fixture of the assembly. According to claim 4, The wings 44 of the upper guide 40 are formed with recessed grooves (44a) in the lower edge, respectively, and the upper edge of the support member 14 for supporting the curved nuclear fuel 12, respectively And a fixing device for the curved fuel assembly for a nuclear reactor, characterized in that it is configured to fit inwardly. According to claim 1, wherein the lower fixing unit 60 comprises a receptacle (62) of a cylindrical structure fitted into the lower inner portion of the flow tube (100); A bottom guide 70 fitted therein; A spider 80 on its lower side; And, And a straight flow guide member 90 on the lower side thereof, And a center rod tip (7) forming a lower end of the center rod (5) is fitted into the fixing groove (84) of the spider (80). The method of claim 7, wherein the receptacle (62) is fitted to the inside of the lower portion of the flow pipe (100), or a structure that is directly welded to the lower end thereof; A diameter reducing portion 64a is provided on an inner surface thereof, and upper and lower sides thereof form upper and lower conical surfaces 64b and 64c inclined toward the diameter reducing portion 64a; Concave grooves 66 into which the lower guide 70 is inserted are respectively formed in the upper conical surface 64b; A spider (80) for securing a center rod tip (7) is arranged at the diameter reducing portion (64a); And, The lower conical surface (64c) of the spider 80 is fixed structure of the nuclear fuel assembly for the reactor, characterized in that the linear flow guide member 90 is arranged in a structure. 8. The lower guide (70) according to claim 7, wherein the lower guide (70) has a hole (72) through which a center rod (5) is fitted; Three wings (74) arranged at intervals of 120 degrees corresponding to the direction of the support member (14) for supporting the curved nuclear fuel (12); The blade 74 has recessed grooves 74a formed in the upper surface thereof so that the lower edges of the supporting member 14 of the curved fuel 12 are correspondingly fitted; And The wing 74 of the lower guide 70 has a middle outer edge thereof fitted into three concave grooves 66 formed in the upper conical surface 64b of the receptacle 62, so that the fuel assembly 10 is cooled by the coolant flow. Fixing device for a curved fuel assembly for a reactor, characterized in that configured to prevent rotation in the circumferential direction inside the flow tube (100). 8. The spider (8) according to claim 7, wherein the spider (80) has a space (82) formed at the center thereof through which the lower center rod tip (7) of the center rod (5) penetrates; Inside the space 82, when both projections (7a) of the center rod tip (7) is inserted and rotated, a fixing groove (84) is formed to be caught and prevent the extraction to the upper portion; And, The three wings (86) is fixed to the inside of the receptacle (62), the fixing device of the curved fuel assembly for a nuclear reactor, characterized in that the configuration. According to claim 1, wherein the lower fixing unit 60 further includes a linear flow guide member 90 on the lower side of the spider 80 is introduced from the lower end of the flow pipe 100, the curved fuel fuel 12 Fixing device for a curved fuel assembly for a reactor, characterized in that configured to impart straightness to the cooling water flowing in the space (P) between the field. 12. The linear flow guide member (90) according to claim 11, having wings (92) corresponding to the wings (86) of the spider (80), which wings are formed on the lower conical surface (64c) of the receptacle (62). Its outer edges are integrally connected by welding; And The direction of the blade 92 of the linear flow guide member 90 is configured to coincide with the three blades 86 of the spider 80 to flow in the circumferential direction of the coolant that may occur at the inlet of the curved nuclear fuel 12 A device for fixing a curved fuel assembly for a reactor, characterized in that it is configured to improve nonuniformity and reduce fluid induced vibrations. The demountable unit (120) of claim 1, wherein the demountable unit (120) has a latch head (122) positioned above the center rod (5) into which the curved fuel assembly (10) is fitted; A spring cover 126 located on the lower side of the latch head 122; And, An upper end is supported in the spring cover (126), and a lower end thereof is a spring (130) supported from the inside of the upper guide cover (32). The method of claim 13, wherein the spring 130 is compressed by inserting the central rod tip 7 of the nuclear fuel assembly 10 into the spider 80 to be pressed downward, in which state the central rod tip 7 is pressed 90 When rotated, the center rod tip 7 is caught in the securing groove 84 of the spider 80; And The spring 130 pushes the upper guide cover 32 downward with respect to the clasp head 122 by its elastic restoring force in a compressed state, and the nuclear fuel assembly fitted to the central rod 5 through the upper guide 40. Push the downwards 10 so that the lower guide 70 is supported by the receptacle 62 coupled to the flow tube 100 so that the fuel assembly 10 does not move in its axial direction, but moves in the axial direction, or Fixing device for the curved fuel assembly for a nuclear reactor, characterized in that configured to dampen and prevent vibration.

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