A spent fuel storage grid spacing measuring device

Abstract

The utility model discloses a spent fuel storage grid spacing measuring device, including a fixed claw, a movable claw, a groove and an auxiliary positioning tooling, wherein the fixed claw and the movable claw both include a short side and a long side, and the short side and the long side are perpendicular to each other and form a "7" shape, the short side of the fixed claw is fixedly connected in the groove, the groove and the short side of the fixed claw in the groove form a fixing part, the short side of the movable claw is slidably connected in the fixing part, the fixed claw and the movable claw form a Π-shaped clamp, and the outer bottom of the long side of the groove is fixedly connected to the auxiliary positioning tooling. The utility model has a simple and unique structural design, a scientific and rigorous measurement principle, is not affected by the cone surface structure of the guide port at the top end of the storage casing, is simple and easy to make, has a reasonable and compact structure and is easy to use.

Description

Technical Field

[0001] The utility model belongs to the technical field of nuclear power equipment measurement, and in particular relates to a spent fuel storage grid spacing measuring device. Background Art

[0002] Spent fuel storage grids are used to store irradiated fuel assemblies unloaded from the core and spent fuel assemblies whose burnup has not reached the specified limit, or new fuel assemblies to be loaded into the core before and during shutdown for refueling. They play an important role in improving the safety and reliability of nuclear power plant reactor systems.

[0003] The spent fuel storage grid consists of a base plate, storage casing, coaming and adjustment legs. The storage casing is 4265mm high, each storage casing is a storage unit, and there are 1254 storage units in a unit.

[0004] The design and manufacture of spent fuel storage grids must ensure the safe storage of spent fuel assemblies and prevent criticality and fuel assembly overheating accidents. Therefore, during the manufacturing stage, the centerline spacing of each storage casing after assembly, i.e., the grid pitch, must be strictly controlled, and the dimensional tolerance is ±1.5mm. The top of some types of storage casings is a tapered guide section to provide guidance for the insertion of fuel assemblies. Since the top of some storage casings is a trumpet-shaped guide port, the existing measurement tools on the market cannot directly measure the grid pitch size between adjacent storage casings. Therefore, it is necessary to develop a spent fuel storage grid grid measurement device. Utility Model Content

[0005] The utility model aims to solve the problems of the prior art and provides a spent fuel storage grid spacing measuring device, which is not affected by the cone surface structure of the guide port at the uppermost end of the storage casing and provides a measuring tool capable of directly measuring the grid spacing size between adjacent storage casings of the spent fuel storage grid.

[0006] In order to solve the technical problem, the technical solution of the utility model is: a spent fuel storage grid spacing measuring device, comprising a fixed claw, a movable claw, a groove and an auxiliary positioning tool, the fixed claw and the movable claw each comprising a short side and a long side, and the short side and the long side are perpendicular to each other in a "7" shape, the short side of the fixed claw is fixedly connected in the groove, the groove and the short side of the fixed claw in the groove constitute a fixing piece, the short side of the movable claw is slidably connected in the fixing piece, the fixed claw and the movable claw constitute a Π-shaped clamp, and the outer bottom of the long side of the groove is fixedly connected to the auxiliary positioning tool;

[0007] The end of the fixing piece connected to the movable claw is provided with two mounting holes, and the end of the movable claw connected to the fixing piece is provided with an oblong hole. Locking pieces are provided in the two mounting holes. The locking pieces pass through the mounting holes and the oblong holes in sequence, and finally the movable claw is locked and fixed by the locking cap. The oblong hole of the movable claw slides left and right on the locking piece to achieve the extension or shortening of the movable claw; the minimum distance between the two openings of the Π-shaped clamp is ≥ the height of the storage sleeve.

[0008] Preferably, the auxiliary positioning tooling comprises three slats, which are welded into an "up" shape rotated 90° counterclockwise, and the "up" shaped slat structure rotated 90° counterclockwise is welded to the bottom outside the long side of the groove at the slat end point close to the groove, and the distance D between two slats perpendicular to the same slat in the "up" shape is equal to half of the size of the two relative surfaces of the inner wall of the storage sleeve.

[0009] Preferably, the mounting hole is a round hole, the locking piece is a stud, and the locking nut is a screw nut.

[0010] Preferably, the rear side of the short side of the fixing claw is welded to the inner side of the groove to form a fixing piece, and the right side of the groove is aligned with the right side of the short side of the fixing claw.

[0011] Preferably, the width of the groove matches the width of the short side of the fixed claw, the width of the groove matches the width of the short side of the movable claw, and the locking piece is adapted to the oblong hole.

[0012] Preferably, the locking piece is welded on the groove and passes through the mounting hole and the oblong hole.

[0013] Preferably, the fitting clearance between the width of the oblong hole and the locking piece is ≤0.1mm, the assembly clearance between the width of the groove and the short side width of the fixed claw is ≤0.1mm, and the assembly clearance between the width of the groove and the short side width of the movable claw is ≤0.1mm.

[0014] Compared with the prior art, the advantages of the utility model are:

[0015] The utility model provides a spent fuel storage grid spacing measuring device. The device has a simple and unique structural design, a scientific and rigorous measuring principle, high accuracy, is not affected by the cone surface structure of the guide port at the uppermost end of the storage casing, is simple and easy to make, has a reasonable and compact structure and is easy to use. The device can control and measure the grid spacing of adjacent cells of the spent fuel storage grid to meet the functional requirements, and has significant progress in technology and operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 , a schematic diagram of the use of a spent fuel storage grid spacing measuring device of the utility model;

[0017] Figure 2, a schematic structural diagram of a spent fuel storage grid spacing measuring device of the utility model;

[0018] Figure 3 , a left view of a spent fuel storage grid spacing measuring device of the utility model;

[0019] Figure 4 , a schematic diagram of the fixed claw structure of a spent fuel storage grid spacing measuring device of the utility model;

[0020] Figure 5 , a schematic diagram of the structure of movable claws of a spent fuel storage grid spacing measuring device of the utility model;

[0021] Figure 6 , a schematic diagram of the structure of a groove connector of a spent fuel storage grid spacing measuring device of the utility model;

[0022] Figure 7 , a left view of an auxiliary positioning tooling structure of a spent fuel storage grid spacing measuring device of the utility model.

[0023] Description of reference numerals:

[0024] 1. Fixed claw, 2. Movable claw, 3. Groove, 4. Auxiliary positioning tool, 5. Locking piece, 6. Π-shaped clamp, 7. Storage sleeve, 8. Mounting hole, 9. Fixing piece;

[0025] 201. Oblong hole. DETAILED DESCRIPTION

[0026] The following describes the specific implementation of the utility model in conjunction with embodiments:

[0027] It should be noted that the structures, proportions, sizes, etc. shown in this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them, and are not used to limit the conditions under which the present invention can be implemented. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0028] The spent fuel storage grid consists of a base plate, storage casing, coaming and adjustment legs. The storage casing is 4265mm high, each storage casing is a storage unit, and there are 1254 storage units in a unit.

[0029] During the manufacturing process, first, the size of each storage sleeve is completely consistent with the adjacent theoretical grid pitch according to the design requirements of the drawing; secondly, the measurement of the grid pitch converts the distance from the center line to the center line into the distance from one surface of the storage sleeve to one surface of the adjacent storage sleeve according to theory; finally, according to the size of the storage sleeve, the placement position of the tooling during measurement is determined, and it is required to avoid the tapered guide opening bevel and fit tightly with the straight edge section below the guide opening of the inner surface of the two adjacent storage sleeves. At this time, use a vernier caliper to directly measure the measuring claws of the tooling, and subtract the thickness of the tooling measuring claws from the reading to obtain the centerline spacing of adjacent cells required by the drawing.

[0030] like Figure 1 As shown in the figure, the two measuring claws of the measuring tool are fitted with the inner edges of two adjacent storage sleeves, and the vernier caliper is used to measure the Figure 1 The dimensions H and L shown are the width of a measuring claw. The grid spacing between two theoretically adjacent storage sleeves can be calculated using the following formula.

[0031] Pitch size d=HL

[0032] Example 1

[0033] like Figures 2 to 7 As shown, the utility model discloses a spent fuel storage grid spacing measuring device, comprising a fixed claw 1, a movable claw 2, a groove 3 and an auxiliary positioning tool 4, wherein the fixed claw 1 and the movable claw 2 each comprise a short side and a long side, and the short side and the long side are perpendicular to each other and form a "7" shape, the short side of the fixed claw 1 is fixedly connected in the groove 3, the groove 3 and the short side portion of the fixed claw 1 in the groove 3 constitute a fixing member 9, the short side of the movable claw 2 is slidably connected in the fixing member 9, the fixed claw 1 and the movable claw 2 constitute a Π-shaped clamp 6, and the outer bottom of the long side of the groove 3 is fixedly connected to the auxiliary positioning tool 4;

[0034] The end of the fixing member 9 connected to the movable claw 2 is provided with two mounting holes 8, and the end of the movable claw 2 connected to the fixing member 9 is provided with an oblong hole 201. The two mounting holes 8 are provided with locking members 5, and the locking member 5 passes through the mounting holes 8 and the oblong holes 201 in sequence, and finally the movable claw 2 is locked and fixed by the locking cap. The oblong hole 201 of the movable claw 2 slides left and right on the locking member 5 to achieve the extension or shortening of the movable claw 2; the minimum distance between the two openings of the Π-shaped clamp 6 is ≥ the height of the storage sleeve.

[0035] The two mounting holes are arranged in parallel in the length direction of the fixing member 9 .

[0036] The function of the fixed claw 1 is to keep the fixed claw 1 immobile after contacting the workpiece during measurement, and then adjust the position of the movable claw 2 to achieve the clamping function. The movable claw 2 is called a movable claw because it can move back and forth along the direction of the oblong hole 201. Its function is to adjust the position of the movable claw 2 back and forth after the fixed claw 1 remains immobile to achieve the clamping function. The function of the groove 3 is to use its groove and the two mounting holes above to achieve the combined connection of the fixed claw 1 and the movable claw 2.

[0037] The auxiliary positioning tool 4 is mainly used to fix the height positions of the two measuring claws, the fixed claw 1 and the movable claw 2, at the middle position of the fitting surface of the inner wall of the storage casing.

[0038] Example 2

[0039] Preferably, the auxiliary positioning tooling 4 comprises three slats, which are welded into an "up" shape rotated 90° counterclockwise, and the "up" shaped slat structure rotated 90° counterclockwise is welded to the bottom outside the long side of the groove 3 at the slat end point close to the groove 3, and the distance D between two slats perpendicular to the same slat in the "up" shape is equal to half of the size of the two relative surfaces of the inner wall of the storage sleeve.

[0040] The auxiliary positioning tool 4 is composed of three strips, and the welding method of the assembly is as follows Figure 7 As shown in the figure, dimension D is half of the relative dimensions of the two faces of the inner wall of the storage casing. Figure 7 The top end shown is assembled and welded with the groove 3 as shown.

[0041] Preferably, the mounting hole 8 is a round hole, the locking member 5 is a stud, and the locking nut is a screw nut.

[0042] Preferably, the rear side of the short side of the fixing claw 1 is welded to the inner side of the groove 3 to form a fixing piece 9 , and the right side of the groove 3 is aligned with the right side of the short side of the fixing claw 1 .

[0043] Preferably, the width of the groove 3 matches the width of the short side of the fixed claw 1 , the width of the groove 3 matches the width of the short side of the movable claw 2 , and the locking piece 5 is adapted to the oblong hole 201 .

[0044] Preferably, the locking member 5 is welded on the groove 3 and passes through the mounting hole 8 and the oblong hole 201 .

[0045] Preferably, the fitting clearance between the width of the oblong hole 201 and the locking piece 5 is ≤0.1mm, the assembly clearance between the width of the groove 3 and the short side width of the fixed claw 1 is ≤0.1mm, and the assembly clearance between the width of the groove 3 and the short side width of the movable claw 2 is ≤0.1mm.

[0046] The assembly method of the utility model is as follows:

[0047] 1. The short side of the fixing claw 1 is assembled into a fixing piece 9 through the groove of the groove 3, ensuring that the right side of the groove 3 is aligned with the right side of the short side of the fixing claw 1;

[0048] 2. Use a marker pen to mark the position on the fixing claw 1 through the two round holes on the groove 3;

[0049] 3. Fit the two studs to the two round holes on the groove 3;

[0050] 4. Weld the studs on the back of groove 3;

[0051] 5. Use an electric drill to drill holes at the positions of the round holes marked on the fixing claw 1. The hole diameter should be slightly larger than the stud diameter.

[0052] 6. Use the punched holes and studs to assemble the fixing claw 1 and the groove 3, and weld the inner side of the groove 3 on the back of the fixing claw 1 to ensure that the fixing claw 1 and the groove 3 will not be displaced relative to each other;

[0053] 7. Put the movable claw 2 through the short side with the oblong hole and use the stud to ensure that the movable claw 2 can move left and right along the direction of the oblong hole after assembly; finally, install the nut on the stud to fix it;

[0054] 8. Assemble and weld one end of the top of the auxiliary positioning tool 4 formed by welding three strips to the groove 3.

[0055] The working principle of the utility model is as follows:

[0056] During measurement, the auxiliary positioning tool 4 is placed on the inner wall of the storage sleeve that needs to be measured, and then moved as a whole to adjust the position, and the fixed claw 1 and the auxiliary positioning tool 4 are respectively attached to the two adjacent inner walls of the storage sleeve. The position of the movable claw 2 through the oblong hole is made to fit on the inner wall of the adjacent storage sleeve. Finally, the nut on the groove 3 is tightened to ensure that the movable claw 2 does not move, and then the ends of the two measuring claws are removed for measurement. The width of one measuring claw is subtracted from the measurement result, and the result is the center line spacing of the two adjacent storage chambers.

[0057] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in this field without departing from the purpose of the present invention.

[0058] Many other changes and modifications can be made without departing from the concept and scope of the utility model. It should be understood that the utility model is not limited to a specific embodiment, and the scope of the utility model is defined by the appended claims.

Claims

1. A spent fuel storage grid spacing measuring device, characterized in that: The invention comprises a fixed claw (1), a movable claw (2), a groove (3) and an auxiliary positioning tool (4), wherein the fixed claw (1) and the movable claw (2) each comprise a short side and a long side, and the short side and the long side are perpendicular to each other and form a "7" shape, the short side of the fixed claw (1) is fixedly connected in the groove (3), the groove (3) and the short side of the fixed claw (1) in the groove (3) form a fixing piece (9), the short side of the movable claw (2) is slidably connected in the fixing piece (9), the fixed claw (1) and the movable claw (2) form a Π-shaped clamp (6), and the outer bottom of the long side of the groove (3) is fixedly connected to the auxiliary positioning tool (4); One end of the fixing member (9) connected to the movable claw (2) is provided with two mounting holes (8), and one end of the movable claw (2) connected to the fixing member (9) is provided with an oblong hole (201). The two mounting holes (8) are provided with locking members (5). The locking member (5) passes through the mounting holes (8) and the oblong holes (201) in sequence, and finally the movable claw (2) is locked and fixed by a locking cap. The oblong hole (201) of the movable claw (2) slides left and right on the locking member (5) to extend or shorten the movable claw (2); the minimum distance between the two openings of the Π-shaped clamp (6) is ≥ the height of the storage sleeve.

2. A spent fuel storage grid spacing measuring device according to claim 1, characterized in that: The auxiliary positioning tool (4) comprises three slats, which are welded into an "up" shape rotated 90° counterclockwise, and the slat end points of the "up" shape slat structure close to the groove (3) are welded to the bottom of the outer side of the long side of the groove (3), and the distance D between two slats perpendicular to the same slat in the "up" shape is equal to half the size of the two relative surfaces of the inner wall of the storage sleeve.

3. A spent fuel storage grid spacing measuring device according to claim 1, characterized in that: The mounting hole (8) is a round hole, the locking piece (5) is a stud, and the locking nut is a screw nut.

4. A spent fuel storage grid spacing measuring device according to claim 1, characterized in that: The rear side of the short side of the fixing claw (1) is welded to the inner side of the groove (3) to form a fixing piece (9), and the right side of the groove (3) is aligned with the right side of the short side of the fixing claw (1).

5. A spent fuel storage grid spacing measuring device according to claim 1, characterized in that: The width of the groove (3) matches the width of the short side of the fixed claw (1), the width of the groove (3) matches the width of the short side of the movable claw (2), and the locking piece (5) matches the oblong hole (201).

6. A spent fuel storage grid spacing measuring device according to claim 1, characterized in that: The locking piece (5) is welded to the groove (3) and passes through the mounting hole (8) and the oblong hole (201).

7. A spent fuel storage grid spacing measuring device according to claim 1, characterized in that: The matching clearance between the width of the oblong hole (201) and the locking member (5) is ≤0.1 mm, the assembly clearance between the width of the groove (3) and the width of the short side of the fixed claw (1) is ≤0.1 mm, and the assembly clearance between the width of the groove (3) and the width of the short side of the movable claw (2) is ≤0.1 mm.

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