Light Water Reactor Nuclear Fuel Rod Loading Device

Abstract

The present invention relates to a light water reactor nuclear fuel rod loading device, which can measure the loading force of nuclear fuel rods acting on each unit of a support grid in an environment identical to the nuclear fuel rod loading environment, so as to provide a data basis for optimizing the nuclear fuel assembly process. According to the light water reactor nuclear fuel rod loading device of the present invention, the light water reactor nuclear fuel rod loading device includes a grid support and a loading power device. The loading power device is provided with a traction module that reciprocates towards the grid support. The light water reactor nuclear fuel rod loading device further includes: a hollow cladding tube sample, located on one side of the support grid fixed by the grid support, having the same diameter as the nuclear fuel rod cladding tube; a tie rod, one end of which passes through the unit of the support grid during use and is configured to be coupled to the cladding tube sample, and the other end of which is configured to be coupled to the traction module; and a measuring mechanism, provided on the tie rod, for measuring the loading force of the traction module pulling the tie rod.

Description

Technical Field

[0001] The present invention relates to a device for measuring the loading force of a light water reactor nuclear fuel rod. More specifically, the present invention relates to a device for measuring the loading force of a light water reactor nuclear fuel rod that can obtain data for optimizing the nuclear fuel assembly process and establishing improvement plans by measuring the loading force of the nuclear fuel rod acting on each unit of the support grid in a state where an environment identical to the nuclear fuel rod loading environment is provided. Background Art

[0002] Light water reactor nuclear power generally uses enriched uranium with the proportion of uranium - 235 increased to 2 - 5%. In order to process it into nuclear fuel for use in a nuclear reactor, it is formed into cylindrical pellets (Pellet) weighing about 5 g by shaping the uranium. In addition, energy for nuclear fission is provided by the nuclear fuel.

[0003] The nuclear fuel arranged inside the nuclear reactor is composed of units such as Figure 1 the nuclear fuel assembly 10 shown. The nuclear fuel assembly 10 is composed of a skeleton and nuclear fuel rods 20. The skeleton is composed of an upper end fixing body 11, a lower end fixing body 12, and a support grid 13. The nuclear fuel rods 20 are loaded into the support grid 13 and are supported by springs and shallow depressions formed inside the support grid 13. Each nuclear fuel rod 20 includes uranium in a plurality of pellets 21 as a single pellet unit, and a zirconium alloy cladding tube 22 for protecting the uranium and preventing radioactive leakage, and is arranged in a bar shape.

[0004] Through Figure 2 the nuclear fuel rod loading device 30 shown, the process of loading the nuclear fuel rods 20 into such a nuclear fuel assembly 10 is performed. The nuclear fuel rod loading device 30 includes: a nuclear fuel rod support 31 for arranging the nuclear fuel rods; a grid support 32 provided on one side of the nuclear fuel rod support 31 for arranging the support grid 13 of the nuclear fuel assembly 10; and a loading power device 33 provided on one side of the grid support 32, performing linear reciprocating movement toward the grid support 32, and configured to use a loading rod to pull the nuclear fuel rods on the nuclear fuel rod support 31 to the support grid 13, thereby loading the nuclear fuel rods into Figure 3 the unit (cell) 13a of the support grid 13 shown. Among them, the nuclear fuel rods are loaded into the support grid 13 in columnar units in sequence.

[0005] In addition, although the surface damage of nuclear fuel rods and the changes in nuclear fuel assemblies occurring during the process of loading nuclear fuel rods into the support grid 13 of the nuclear fuel assembly 10 are managed in accordance with inspection standards, there is currently no technical information regarding the effects of different nuclear fuel rod loading conditions on nuclear fuel rods and nuclear fuel assemblies. In the assembly process of nuclear fuel assemblies, due to the lack of test data and technical data related to main process variables such as nuclear fuel rod loading force and loading speed, it is difficult to optimize the process and establish improvement plans. Therefore, in order to understand the deformation trend of nuclear fuel assemblies under different nuclear fuel rod loading conditions, it is necessary to construct nuclear fuel rod loading data through tests of loading nuclear fuel rods onto the support grid.

[0006] Prior art documents

[0007] Patent documents

[0008] Patent Document 1: Korean Patent Publication No. 10-2019-0091716 Summary of the invention

[0009] Problems to be solved by the invention

[0010] The present invention is proposed to solve the above problems, and the object of the present invention is to provide a light water reactor nuclear fuel rod loading force measuring device that can use an existing nuclear fuel rod loading device to load a test nuclear fuel rod between the cells of a support grid and measure the nuclear fuel rod loading force acting on the cells of the support grid.

[0011] Means for solving the problems

[0012] To achieve the above object, the present invention provides a light water reactor nuclear fuel rod loading force measuring device provided in a nuclear fuel rod loading device, the nuclear fuel rod loading device including a grid support and a loading power device, the loading power device being provided with a traction module that reciprocally moves toward the grid support, the light water reactor nuclear fuel rod loading force measuring device including: a hollow cladding tube sample located on one side of the support grid and having the same diameter as the nuclear fuel rod cladding tube; a pull rod, one end of which passes through the cell of the support grid and is coupled to the cladding tube sample, and the other end of which is coupled to the traction module; and a measuring mechanism provided on the pull rod for measuring the force with which the traction module pulls the pull rod.

[0013] Here, preferably, the traction module is provided with a guide plate, the guide plate being formed with a through hole that penetrates both sides, the other end of the pull rod passing through one side of the through hole of the guide plate and being screwed to the measuring mechanism on the other side of the through hole of the guide plate.

[0014] And, preferably, the pull rod includes a retainer for engaging with the cladding tube sample, one end of the retainer is screwed to one end of the pull rod, and the other end of the retainer passes through the cladding tube sample and engages with a retainer cap, thereby being coupled to the cladding tube sample.

[0015] Here, preferably, steps for supporting the cladding tube sample are formed on the retainer cap corresponding to one side of the cladding tube sample and on the retainer corresponding to the other side of the cladding tube sample.

[0016] Effects of the Invention

[0017] The light water reactor nuclear fuel rod loading force measuring device according to the present invention can utilize an existing nuclear fuel rod loading device, and thus does not require additional equipment for measuring the nuclear fuel rod loading force, having the effect of improving economy.

[0018] And, the light water reactor nuclear fuel rod loading force measuring device according to the present invention can provide the same environment as nuclear fuel rod loading, and thus has the effect of improving the measurement reliability of the loading force for loading nuclear fuel rods onto a support grid.

[0019] And, the light water reactor nuclear fuel rod loading force measuring device according to the present invention can optimize the nuclear fuel assembly process by constructing the loading force data of the support grid, having the effect of effectively establishing improvement plans. Brief Description of the Drawings

[0020] Figure 1 Schematic diagram of a light water reactor nuclear fuel assembly and nuclear fuel rods.

[0021] Figure 2 Schematic diagram of a nuclear fuel rod loading device for a light water reactor nuclear fuel assembly.

[0022] Figure 3 Exploded schematic diagram of a light water reactor nuclear fuel rod loading force measuring device according to a preferred embodiment of the present invention.

[0023] Figure 4 Schematic diagram of a light water reactor nuclear fuel rod loading force measuring device according to a preferred embodiment of the present invention.

[0024] Figure 5 Schematic diagram of a state where a light water reactor nuclear fuel rod loading force measuring device according to a preferred embodiment of the present invention is installed in a nuclear fuel rod loading device of a nuclear fuel assembly. Detailed Description of the Preferred Embodiment

[0025] The terms or words used in this specification and claims are not to be construed in accordance with their dictionary meanings. Instead, based on the principle that the inventor can appropriately define the concepts of terms in order to best explain their invention, they should be interpreted as meanings and concepts that conform to the technical idea of the present invention.

[0026] Next, with reference to the accompanying Figures 3 to 5 , a light water reactor nuclear fuel rod loading force measuring device according to a preferred embodiment of the present invention will be described.

[0027] The light water reactor nuclear fuel rod loading force measuring device according to the present invention can utilize an existing nuclear fuel rod loading device to measure the loading force acting on each unit of the support grid in an environment identical to the nuclear fuel rod loading operation environment. When measuring the loading force of each unit of the support grid by the light water reactor nuclear fuel rod loading force measuring device, the loading force data of each unit of the support grid corresponding to the nuclear fuel rod loading conditions can be digitalized, so that technical data for optimizing the nuclear fuel assembly process can be obtained.

[0028] As Figure 3 and Figure 4 shown, the light water reactor nuclear fuel rod loading force measuring device according to the present invention includes: a cladding tube sample 100, a pull rod 200, and a measuring mechanism 300.

[0029] The cladding tube sample 100 is used to measure the loading force of each unit 13a of the support grid 13 and is configured to have the same diameter and material as the zirconium cladding tube of the nuclear fuel rod. The cladding tube sample 100 is configured in a hollow form that penetrates both sides. By replacing the nuclear fuel rod 20 with the cladding tube sample 100, the operator can similarly apply the loading conditions of the nuclear fuel rod to the support grid 13, thereby improving the reliability of the measurement of the loading force of each unit 13a of the support grid 13. The cladding tube sample 100 is arranged to be pulled by being coupled to the pull rod 200.

[0030] The pull rod 200 is provided between the cladding tube sample 100 and the measuring mechanism 300 and serves as a medium mechanism for pulling the cladding tube sample 100 through a traction module 40 (refer to Figure 5 ). The pull rod 200 has the form of a bar corresponding to the loading rod. One end of the pull rod 200 is coupled to the cladding tube sample 100, and the other end of the pull rod 200 is coupled to the measuring mechanism 300. Preferably, the pull rod 200 and the measuring mechanism 300 are configured to be mutually screwable. Since the pull rod 200 and the measuring mechanism 300 are configured to be separable from each other, the pull rod and the measuring mechanism can be arranged on both sides with reference to the guide plate 41 of the following traction module 40, thereby improving the efficiency of maintenance of the measuring mechanism 300. As Figure 3As shown, a bolt M is formed at the other end of the pull rod 200, and a coupling rod is formed on the measuring mechanism 300, and a nut F is formed on the coupling rod.

[0031] One end of the pull rod 200 further includes a retainer 210 and a retainer cap 220 for coupling with the cladding tube sample 100.

[0032] The retainer 210 is a medium mechanism for disassembling and assembling the hollow cladding tube sample 100 to the pull rod 200, and bolts M for screwing are formed at both ends. A nut F for screwing with the retainer 210 is formed at one end of the pull rod 200. The retainer 210 is formed to have a diameter capable of passing through the inside of the cladding tube sample 100, and a step 211 is formed on the outer peripheral surface of the retainer 210 so that the retainer 210 does not completely pass through the cladding tube sample 100. Preferably, the outer diameter of the step 211 of the retainer 210 is equal to the outer diameter of the cladding tube sample 100. With the structure having the step 211 of the retainer 210, as Figure 4 shown, the position of the cladding tube sample 100 can be guided on the retainer 210. The retainer 210 has a length that passes through the cladding tube sample 100 and the other end of the retainer 210 can be exposed to the outside of the cladding tube sample 100.

[0033] The retainer cap 220 functions to fix the cladding tube sample 100 together with the retainer 210. The retainer cap 220 is arranged to be able to screw with the bolt M of the retainer 210 exposed to the outside of the cladding tube sample 100. A nut F capable of screwing with the bolt M of the retainer 210 is formed on the retainer cap 220. The retainer cap 220 also forms a step 221. The retainer cap 220 is formed to have the same outer diameter as the cladding tube sample 100 so that interference can be prevented when the cladding tube sample 100 is loaded into the unit 13a of the support grid 13, and at the same time, it is configured to have a step difference so that a part of the outer diameter of the retainer cap 220 can be located inside the cladding tube sample 100. In this way, the retainer cap 220 forms a step 221. By forming the step 221 of the retainer cap 220, the retainer cap 220 can be in close contact with the cladding tube sample 100, thereby making the bonding force more firm.

[0034] The measuring mechanism 300 is used to measure the loading force acting on the unit 13a of the support grid 13 when the pull rod 200 pulls the cladding tube sample 100 through the traction module 40. In order to enable the acting force of the traction module 40 to directly act on the measuring mechanism 300 during the process of the traction module 40 pulling the pull rod 200, the measuring mechanism 300 is arranged along the direction of movement towards the traction module 40 on the pull rod 200. As Figure 4 shown, the measuring mechanism 300 is caught and supported by the guide plate 41 of the traction module 40. Figure 5As shown, a through hole 41a penetrating both sides is formed on the guide plate 41, and the measuring mechanism 300 is set to have a diameter larger than that of the through hole 41a, so that it can be caught and supported by the surface of the guide plate 41. Preferably, the measuring mechanism 300 is a rod-shaped unit. The measuring mechanism 300 is detachably provided on the pull rod 200, as Figure 4 shown, the measuring mechanism 300 includes a coupling rod 310 and a protection pin 320. The coupling rod 310 is a member that can be disassembled and assembled on the pull rod 200, and is formed to have a diameter smaller than the diameter of the through hole 41a of the guide plate 41. One end of the coupling rod 310 is set to be able to be screwed to the end of the pull rod 200, and the other end of the coupling rod 310 is set to be able to be screwed to the measuring mechanism 300. The protection pin 320 is used to prevent the measuring mechanism 300 from colliding with the members on one side when the measuring mechanism 300 is pulled and moved by the traction module 40, and the protection pin 320 is coupled to the measuring mechanism 300.

[0035] Next, the measurement process of the loading force of the light water reactor nuclear fuel rod loading force measuring device composed of the above components will be described.

[0036] The operator installs the light water reactor nuclear fuel rod loading force measuring device between the support grid 13 and the traction module 40 of the loading power device 33. For this purpose, in a state where one end of the pull rod 200 is separated from the coupling rod 310, after the coupling rod 310 passes through from one side of the through hole 41a of the guide plate 41, the coupling rod 310 is screwed to the end of the pull rod 200. At this time, the measuring mechanism 300 is caught and supported by one surface of the guide plate 41. Herein, one surface of the guide plate 41 refers to the surface in the direction in which the traction module 40 pulls the cladding tube sample 100.

[0037] After the operator passes the pull rod 200 from one side of the support grid 13 to the other side, the cladding tube sample 100 is coupled to the holder 210 of the pull rod 200 exposed on the other side of the support grid 13. At this time, the end of the cladding tube sample 100 is caught by the step 211 of the holder 210, so its position is guided.

[0038] The operator screws the holder cap 220 to the end of the holder 210 exposed outside the cladding tube sample 100, as Figure 5 shown, so that the cladding tube sample 100 is in a state of being coupled to the pull rod 200 on the other side of the support grid 13.

[0039] The operator starts the loading power device 33 to move the traction module 40 to the right in the figure. The pull rod 200 provided on the traction module 40 moves together with the traction module 40. As the pull rod 200 moves, the cladding tube sample 100 is loaded into the unit 13a of the support grid 13. Here, the cladding tube sample 100 generates a loading force due to the resistance of the unit 13a of the support grid 13, and this loading force is transmitted to the measuring mechanism 300 through the pull rod 200. That is, during the process of the traction module 41 pulling the pull rod 200, the force acting on the guide plate 41 is transmitted to the measuring mechanism 300 unchanged. Therefore, the light water reactor nuclear fuel rod loading force measuring device can measure the loading force of the nuclear fuel rod of the unit 13a to be measured.

[0040] After measuring the loading force of a specific unit 13a of the support grid 13 through the above operation, the operator removes the cladding tube sample 100 from the pull rod 200 and performs test setting work so that the cladding tube sample 100 can pass through other units of the support grid 13. Then, the above series of operations are performed to measure the loading force of other units.

[0041] As described above, the operator measures the loading force of all units 13a of the support grid 13 and digitizes it, so that the nuclear fuel assembly process can be optimized and an improved plan can be effectively constructed.

[0042] In the above, specific examples of the present invention have been described in detail, but various deformations and modifications can be made without departing from the scope of the technical idea of the present invention, which is obvious to those of ordinary skill in the technical field to which the present invention belongs, and obviously these deformations and modifications are within the scope of the appended claims.

[0043] Description of reference numerals

[0044] 100: Cladding tube sample 200: Pull rod

[0045] 210: Retainer 211, 221: Step

[0046] 220: Retainer cap 300: Measuring mechanism

[0047] 310: Binding rod 320: Protection pin

[0048] M: Bolt F: Nut

Claims

1. A light water reactor nuclear fuel rod loading device, characterized in that, The light water reactor nuclear fuel rod loading device includes a grid support and a loading power device. The loading power device is provided with a traction module that reciprocates towards the grid support. The light water reactor nuclear fuel loading device further includes: A hollow cladding tube sample, located on one side of the support grid fixed by the grid support, having the same diameter as the nuclear fuel rod cladding tube; A pull rod, one end of which passes through the unit of the support grid during use and is configured to be coupled to the cladding tube sample, and the other end of which is configured to be coupled to the traction module; and A measuring mechanism, provided on the pull rod, for measuring the loading force of the traction module pulling the pull rod; The pull rod includes a retainer for coupling to the cladding tube sample. One end of the retainer is screwed to one end of the pull rod, and the other end of the retainer is configured to pass through the cladding tube sample during use and be coupled to a retainer cap, thereby being coupled to the cladding tube sample.

2. The light water reactor nuclear fuel rod loading device according to claim 1, characterized in that The traction module is provided with a guide plate. The guide plate is formed with a through hole penetrating both sides of the guide plate. The other end of the pull rod passes through one side of the through hole of the guide plate during use and is screwed to the measuring mechanism on the other side of the through hole of the guide plate.

3. The light water reactor nuclear fuel rod loading device according to claim 1 or 2, characterized in that On the retainer cap corresponding to one side of the cladding tube sample and the retainer corresponding to the other side of the cladding tube sample, there are formed steps for supporting the cladding tube sample.

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