JPS6150098A - Overhaul and re-assembly device for nuclear fuel aggregate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a nuclear fuel assembly disassembly/reassembly apparatus for disassembling and reassembling nuclear fuel assemblies.

(Prior art) As shown in Fig. 15, a nuclear fuel assembly a of a pressurized water reactor is
υ includes a large number of nuclear fuel rods (2), a plurality of support grids (4) each having a large number of openings for individually receiving each of the nuclear fuel rods (2), and a plurality of hollow guide tubes for control rods (3). ), a bottom nozzle (5) with a large number of flow holes, and an upper nozzle (1) with a large number of flow holes, each support grid (4) having a bottom nozzle (5) with a large number of flow holes formed therein, and a top nozzle (1) with a large number of flow holes formed therein, and each of the support grids (4) has a bottom nozzle (5) with a large number of flow holes formed therein, and an upper nozzle (1) with a large number of flow holes formed therein. 3) are arranged at intervals in the longitudinal direction, and each of the hollow guide tubes (3) is inserted and fixed through each of the support grids (4) so that the hollow guide tubes (3) are arranged at intervals in the longitudinal direction.
3) are supported in parallel to each other, each of the nuclear fuel rods (21) is inserted into each opening of each of the support grids (2) and supported elastically and parallel to each other, and each of the hollow guide tubes (310 with both ends thereof The bottom nozzle plate (5) and the top nozzle plate (
It is inserted and welded into the communicating hole of 1).

The nuclear fuel rod (2) is composed of a fuel cladding tube (8), a presser foot (9), and a pellet (101).

Also, (6) is the measurement tube, (7) is the nozzle spring, αυ
is the bottom plate of the upper nozzle (1), and ■ is the top plate of the lower nozzle (5). When the nuclear fuel rod (2) is broken or damaged, it is necessary to remove it from the nuclear fuel assembly αυ, repair it, and then reassemble it. In that case, a threaded sleeve (not shown) inserted and welded to the upper or lower end of the control rod hollow guide tube (3) is attached to the bottom plate Q, ! of the upper nozzle (1). 9 or the lower nozzle (5) into the communication hole provided in the bottom plate a9, and screw the fixing screws into the respective threaded sleeves to connect the upper nozzle (1) or the lower nozzle (5) to the hollow guide tube ( 3), remove the fixing screws and remove the upper nozzle (1) or the lower nozzle (5) from the end of the hollow guide tube (31). By removing the nuclear fuel rod (2), the nuclear fuel assembly (
If), it can be removed and reassembled by performing the reverse operation.

(Problems to be Solved by the Invention) After the nuclear fuel assembly αB is used in a nuclear reactor, the screw threads of the fixing screws are likely to be deformed, seized, galled, etc. When removing the upper nozzle (1) or the lower nozzle (5) from the end of the hollow guide tube (3) and removing it from the nuclear fuel rod (21f!: nuclear fuel assembly I) and when reassembling it, Furthermore, when mounting with fixing screws, there is a problem in that uneven tightening force causes cracks and looseness.

(Means for Solving the Problems) The present invention addresses the above-mentioned problems by providing a plurality of support grids each having a large number of nuclear fuel rods and a large number of openings for individually receiving each of the nuclear fuel rods. , having a plurality of hollow guide tubes for control rods, a bottom nozzle plate having a plurality of flow holes perforated therein, and an upper nozzle plate having a plurality of flow holes perforated therein; The hollow guide tubes are arranged at intervals in the longitudinal direction, and the hollow guide tubes are inserted and fixed into the support grids so that the hollow guide tubes are supported in parallel to each other, and the nuclear fuel rods are supported in parallel to each other in the support grids. A nuclear fuel assembly is disassembled and reassembled, in which the hollow guide tubes are fully inserted into the respective openings and supported elastically and parallel to each other, and both ends of the hollow guide tubes are inserted and fixed into the communicating holes of the bottom nozzle plate and the top nozzle plate. In a disassembly/reassembly device for a nuclear fuel assembly to be assembled, a cylindrical housing for receiving the nuclear fuel assembly;
An upper fixing device for the fuel assembly, which is movably provided on the side of the cylindrical housing near the opening of the housing, and a welded part cutter, which is movably provided at the opening of the cylindrical housing. a fuel rod insertion/extraction device movably provided in the opening of the cylindrical housing; a holding device for an upper nozzle plate provided in the opening of the cylindrical housing; and an opening in the front housing. A disassembly/reassembly device for a nuclear fuel assembly is characterized in that it is configured with a hollow guide tube expansion coupling device movably provided in the upper nozzle or the lower nozzle. The object of the present invention is to provide a disassembly/reassembly device for a nuclear fuel assembly that can prevent deformation, seizure, galling, or rattling of threads, etc., which occurs when a fixing screw is used to attach a nuclear fuel assembly to the end of a hollow guide tube. .

(Embodiment) Next, the nuclear fuel assembly disassembly/reassembly apparatus of the present invention will be explained based on an embodiment 1c shown in FIGS. 1 to 14.
In the figure, (1) is the upper nozzle, (2) is a large number of nuclear fuel rods, (
3) is a plurality of guide tubes for control rods, (4) is a plurality of support grids, (5) is a bottom nozzle, and (11) is each of the above parts (1) to (
(101) is a cylindrical housing that receives the nuclear fuel assembly (IB), (129) is the uppermost end of the cylindrical housing (101), and (102) is the uppermost end of the same (129). ) The nuclear fuel assembly guide part (105) in Figure 1.2 is provided continuously with the guide part (10
2) A support grid (4) attached to the side of the cylindrical housing (101) below and a support stand for the fixing device of the upper nozzle (1), (104) are attached to the front and back on the support stand (105). A total of 4 drive units installed on the left and right positions (106
) is a rod that is moved forward and backward by each drive device (104), and (103) is a support grid and an upper nozzle support piece attached to the tip of each rod (1).
When 104) is driven in one direction, each lot)F (106
) and each support piece (103) move forward, and each support piece (103
) contacts and fixes the upper nozzle (1), the uppermost support grid (4), and the support grid (4) immediately below it, and drives each drive device (IQ4) in the other direction. Then, each rod (106) and support piece Qo3) retreat, and each support piece (103) separates from the upper nozzle (1), the uppermost support grid (4), and the support grid (4) directly below it. , and it's time to release these. Fig. 3 shows the position measuring device of the upper nozzle (1), and the position measuring device of the upper nozzle (1) is connected to the dial gauge mounting base (1).
Electric dial gauge (151) and dial gauge rod (154) attached to the same mounting base (150) as in No. 5
and the uppermost end (129) of the cylindrical casing (101).
The mounting base (150) and the electric dial gauge (151) are fitted into the positioning pin holes (153) provided in the
f, and a positioning pin (152) to hold it in a predetermined high position (see (A)). In addition, (107) in Fig. 4 is a cutter for cutting off the welded part (124) between the bottom plate (lυ) of the upper nozzle (1) and the hollow guide tube (3) for the control rod (see Fig. 5). The cutter (107) is rotated and moved up and down by a drive device (not shown) of the weld section cutting device, and the drive device is moved by a moving device (not shown) to the cylindrical housing (107). 101)
It is movably supported at the uppermost end (opening') (129) of. In addition, (10B) in FIGS. 6 and 7 is a drive device for the fuel rod insertion/extraction device, (109) is a support member integrated with the drive device (10B), and the drive device (108)
The supporting member (109) is also movably supported at the uppermost end (129) of the cylindrical casing (101) by a moving device (not shown). Also, (ul) is the drive device (
The pawl (110) connected to the drive shaft of the same drive (1
When the drive device (108) is driven in one direction with a sleeve surrounding the sleeve (11) and fixed to the support member (109), the pawl (111) rises and contracts radially inward. to grasp the nuclear fuel rod (2) and the drive device (1).
08) f: When driven in the other direction, the pawl (111) descends and expands radially outward to release the nuclear fuel rod (2). FIG. 7 also shows another embodiment of the nuclear fuel rod insertion/extraction device (125) shown in FIGS. 5 and 6. In this embodiment, the nuclear fuel rod insertion/extraction device (126)
is composed of a sleeve (112), a pressing rod (113), and a holding rubber material (114). Also, Section 9.1
Figure 0.11 shows a nuclear fuel rod insertion/extraction device in which dummy nuclear fuel rods (123) are inserted into a nuclear fuel assembly (111) to prevent them from buckling each other.
3) shows the fuel rod insertion guide device that guides the
The fuel rod insertion guide device is composed of a drive device (115), a drive shaft (116), and a two-part guide member (117) that moves in the direction of the arrow via the drive shaft (116). The J device (115) also has a cylindrical casing (101
) is movably supported at the uppermost end (129) of.

Further, FIGS. 12 and 13 show the cylindrical housing (101).
) shows a holding device for the upper nozzle (1) provided at the uppermost end (opening) (129) of the upper nozzle (1).
) is attached to the upper nozzle (1) holding housing (
160), the bottom plate 08 holder (165) of the upper nozzle (1) provided at the bottom of the housing (160), the 7 flange (166) provided at the upper end of the housing (160), and the cylindrical housing (101). ) and a housing with a positioning pin (161X163) that is inserted into a positioning pin hole (153) provided at the top end (129) of the housing to hold the housing (160) at a predetermined height position (see (h)). (1
60) to positioning pins C (161) (163) with nuts (i62) (163). Figure 14 also shows the hollow guide tube (3) for control rods.
The upper end swelling device (128) is shown, and the same swelling device (128) is shown.
128) is the drive device (118) and the same drive device (11B
) and the spacer (119) integrated with the same drive device (118)
The pressing rod (120) and the pressing rod (12) connected to the drive shaft of
The tube expansion rubber material (121) is interposed between the swollen lower end portion of 0) and the holder (119). ), the tube expansion rubber material (121) is compressed, and the upper end of the control rod hollow guide tube (3) bites into the tube expansion groove (122) in the bottom plate of the upper nozzle (1). The upper end of the hollow guide tube (3) is fixed to the bottom plate (IQ) of the upper nozzle (1).
8) also moves the cylindrical casing (1) by a moving device (not shown).
It is movably supported at the top end (129) of 01).

(Function) Next, the function of the nuclear fuel assembly disassembly/reassembly device will be explained. After inserting the nuclear fuel assembly αυ into the cylindrical casing (101) as shown in FIG. Grate and upper nozzle support piece (
103) is advanced, and each support grid support piece (103) is brought into contact with the upper nozzle (1) of the nuclear fuel assembly αυ and each support grid (41 (4)) at the top and immediately below it, and the nuclear fuel assembly ( til'ft support and each of the above support grids (4
The upper nozzle (13) is positioned directly above the ++41. At this time, the bottom of the nuclear fuel assembly aυ is positioned at the bottom of the cylindrical casing (101) by means of a pin (not shown). As shown in FIG. 3, the height position of the upper nozzle (1) is measured by the position measuring device of the upper nozzle (11), and information about the installation status of the upper nozzle (11) is collected. As shown in the figure, insert the positioning pin (152) into the pin hole (153) provided at the top end (129) of the cylindrical casing (101).The height of the positioning pin (152) at this time is ( /=1
Therefore, it can be seen that the height from the reference point provided on the cylindrical housing (101) to the top of the upper nozzle (1) is (cL). In this case, the height of the upper nozzle (1) is G
S).

Next, as shown in FIG. 4, the welded portion (124) between the control rod hollow guide tube (3) and the bottom plate (1B) of the upper nozzle (1) is
Use a cutter (107) to cut it as shown in Figure 5, and after cutting out all the welds (124), remove the upper nozzle (1). Next, the fuel rod insertion/extraction device shown in FIG. 6 or FIG. 8 is moved to the position of the damaged nuclear fuel rod by a moving device (not shown), and the driving device (108)
Nuclear fuel rod (2) that was driven and damaged by a claw (110)
Grasp the upper end and then move the cylindrical housing (101) downward or move the insertion/extraction device (125) or (126) upward to remove the damaged nuclear fuel rod (2). . Next, the dummy fuel rod (123) is inserted into the fuel rod insertion/extraction device (125)' or (12
6), attach the guide member (117) shown in Fig. 9.10 to an appropriate position, and then insert the cylindrical casing (101) or the fuel rod insertion/extraction device (1
25) or (126) to install the dummy fuel rod (
123). As shown in FIG. 11, if the tip of the dummy fuel rod (123) is formed into a conical shape, it can be easily inserted into the support grid (4).

Next, using the upper nozzle holding device shown in FIG. 13, the upper nozzle (1) is returned to the upper position of the fuel assembly αυ. Locating pins (161) (163) shown in Figure 13
The height from the top of the cylindrical housing (101) to the top surface of the upper nozzle is α□) (α2)
) is the height of the pin (A), which is the measurement result measured by the nozzle position measuring device shown in Fig. 3, and the height from the reference point of the cylindrical housing (Lot) to the top of the upper nozzle (1). body) Nyo9 has been adjusted. In this case, the height of the upper nozzle (1) is (S). When the upper nozzle (1) is placed on the nozzle holder (165) and the nozzle holder is moved downward, it first comes into contact with the support piece (i03) and the nozzle guide, and the proper position is corrected. It is done.

As a result, the control rod hollow guide tube (3) is connected to the upper nozzle (1).
) into the mounting hole along the taper of the bottom plate QE9. In this state, positioning pin (161X163)'t pin hole (1
53) and remove the upper nozzle (1). With the above steps, the upper nozzle +IJ returns to its optimum state. The lengths of the positioning pins (161) (163) are not necessarily equal. Alternatively, the same result can be obtained by first attaching and adjusting the nozzle holder R and then inserting the upper nozzle (1). According to the above, the upper nozzle (1) returns to the upper position of the nuclear fuel assembly αυ, but in this state, the hollow guide tube expansion coupling device (t28) is moved to the position of the control rod hollow guide tube (3). move it. A tube expansion groove (122) is cut in the bottom plate QfC of the upper nozzle (1), and when the tip of the expansion coupling device (128) is inserted into the control rod hollow guide tube (3), the spacer (119) K The tube expansion rubber (121) corresponds to the tube expansion groove (122). The tube expansion is performed by pulling up the pressing frame (120) using the drive device (US). The state after expansion is as shown in FIG. The upper nozzle (IJ) is attached to the fuel assembly aυ by pipe expansion. Meanwhile, the damaged nuclear fuel rod (2) is replaced with a dummy fuel rod (123), and the repair is completed. After that,
Remove the support piece (103) and the nozzle guide and take out the fuel assembly αυ. Further, the nozzle holding device can be separated into two parts and removed.

(Effects of the Invention) As described above, the present invention includes a plurality of nuclear fuel rods, a plurality of support grids each having a plurality of openings for individually receiving each nuclear fuel rod, and a plurality of hollow guide tubes for control rods. It has a bottom nozzle plate having a plurality of flow holes formed therein, and an upper nozzle plate having a plurality of flow holes formed therein, and each of the support grids is arranged at intervals in the longitudinal direction of each of the hollow guide tubes. At the same time, the hollow guide tubes are inserted and fixed into the support grids so that the hollow guide tubes are supported parallel to each other, and the nuclear fuel rods are inserted into the openings of the support grids so that they are elastically and mutually supported. A nuclear fuel assembly disassembly and reassembly device for disassembling and reassembling a nuclear fuel assembly that is supported in parallel and in which both ends of each of the hollow guide tubes are inserted and fixed into communication holes of the bottom nozzle plate and the upper nozzle plate. , a cylindrical housing for receiving the nuclear fuel assembly; an upper fixing device for the fuel assembly provided on a side of the front housing near the opening of the cylindrical housing so as to be movable in and out; A weld part cutting device is movably provided in the opening of the front-shaped housing, and a fuel rod insertion/cutting device is movably provided in the opening of the front-shaped housing.
It consists of a pull-out device, an upper nozzle plate holding device provided at the opening of the cylindrical housing, and a hollow guide tube expansion coupling device movably provided at the opening of the cylindrical housing. Since the above-mentioned action is performed, there is no possibility of deformation, seizure, galling, or tightening of the threads, etc., that occur when attaching the upper nozzle (or lower nozzle) to the end of the hollow guide tube using a fixing screw. This has the effect of preventing backlash due to uneven application of force.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional side view showing an embodiment of the nuclear fuel assembly disassembly/reassembly apparatus according to the present invention, and FIG.
A cross-sectional plan view of the support grid fixing device taken along line -■, FIG. 3 is a vertical side view showing the position measuring device of the upper nozzle, FIG. 4 is a vertical side view of the weld section cutting device, and FIG. 5 is a vertical side view of the weld section. FIG. 6 is a vertical side view showing an example of the fuel rod insertion/extraction device; FIG. 7 is a view taken in the direction of the arrow in FIG.
■A cross-sectional plan view along the gland; Figure 8 is a longitudinal side view showing another example of the fuel rod insertion/extraction device; Figure 9 shows a fuel rod insertion guide device that is part of the fuel rod insertion/extraction device. Side view,
FIG. 10 is a plan view thereof, FIG. 11 is a side view showing the relationship between the dummy fuel rod and the support grid, FIG. 12 is a plan view showing the holding device of the upper nozzle plate, and FIG. 13 is a longitudinal side view thereof. FIG. 14 is a longitudinal side view showing the hollow guide tube expansion coupling device, and FIG. 15 is a perspective view showing the nuclear fuel assembly. (1) Upper nozzle, (2) Nuclear fuel rod, (end) Hollow guide tube for control rod, (4) Support grid, (5
)...Lower nozzle, αυ...Nuclear fuel assembly, α?
・Bottom plate of upper nozzle (1), (1st group...lower nozzle (
5) Top plate, (tol)... cylindrical casing, (
129)...opening of the cylindrical casing (tol), (
103) (104) (106) Fuel assembly upper fixing device, (125) or (126) Fuel rod insertion/extraction device, (12B) Hollow guide tube expansion coupling expansion device . Sub-Agent Patent Attorney Shige Okamoto 3 people outside the kiln Figure 1 Horse 2 Figure 4 Figure 12 Figure 15

Claims (1)

[Claims] A plurality of nuclear fuel rods, a plurality of support grids each having a plurality of openings for receiving each of the nuclear fuel rods individually, a plurality of hollow guide tubes for control rods, a bottom nozzle plate having a plurality of flow holes; , an upper nozzle plate having a plurality of flow holes bored therein, and each of the support grids is arranged at intervals in the longitudinal direction of each of the hollow guide tubes, and each of the hollow guide tubes has an upper nozzle plate with a plurality of flow holes formed therein. The hollow guide tubes are supported parallel to each other by being inserted into and fixed thereto, the nuclear fuel rods are inserted through the openings of the support grids and supported elastically and parallel to each other, and both ends of the hollow guide tubes are A nuclear fuel assembly disassembly/reassembly apparatus for disassembling and reassembling a nuclear fuel assembly, the nuclear fuel assembly having a part inserted through and fixed into a communicating hole of the bottom nozzle plate and the top nozzle plate, comprising: a cylindrical housing for receiving the nuclear fuel assembly; , an upper fixing device for a fuel assembly that is movably provided on the side of the cylindrical housing in proximity to the opening of the cylindrical housing; a weld part cutting device, a fuel rod insertion/extraction device movably provided in the opening of the cylindrical housing, a holding device for an upper nozzle plate provided in the opening of the cylindrical housing, 1. A disassembly/reassembly device for a nuclear fuel assembly, comprising a hollow guide tube expansion coupling device movably provided in an opening of a housing.