JPH05264778A - Device for gripping nuclear fuel - Google Patents

Abstract

PURPOSE:To provide a device for gripping nuclear fuel which can handle two kinds of PWR fuel assemblies being different in width by one gripper. CONSTITUTION:When a fuel assembly is gripped, the main body of a device is lowered by an air cylinder, a lower guide pin 16 is inserted into a guide pin hole 26 of the fuel assembly 20 and positioning is conducted. At the same time, a cam part 7 formed in the lower end part of the air cylinder lowers along tapered parts 8 of hook pawls 3 and thereby one pair of the hook pawls 3 out of two pairs of them are rotated selectively according to the kind of the fuel assembly to be handled. By raising the main body of the device, subsequently, the fore ends of the paired hook pawls are made to engage with a grip opening 30 of the fuel assembly 20 and an indented part 13 formed in the upper end part of each hook pawl 3 engages with a wedge 14. As the result, pulling-up of the fuel assembly 20 is enabled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel handling operation in a nuclear power plant and a reprocessing plant, and more particularly to a nuclear fuel gripping apparatus suitable for a fuel handling operation in the case of a PWR fuel assembly.

[0002]

2. Description of the Related Art In a fuel handling operation for a PWR fuel assembly at a nuclear power plant, there are generally two types of PWR fuel assemblies having different widths according to each nuclear power plant. Correspondingly, two types of grips for the nuclear fuel gripping device were prepared, and one of them was used by each nuclear power plant.

Examples of the gripping tools related to this type include, for example, Japanese Utility Model Laid-Open No. 59-90897.

By the way, in a reprocessing plant, both BWR fuel assemblies and PWR fuel assemblies are handled, and
In order to handle the fuel by mixing the two types of PWR fuel assemblies having different widths described above, the two types of grips described above are used, and the grips are replaced according to the type of the fuel assembly. There was a problem that the fuel handling work was delayed because the replacement time was generated.

Since the fuel handling work in the reprocessing plant is a critical path work and greatly affects the treatment process and the operation of the reprocessing plant, the fuel handling work cannot be delayed.

[0006]

In the above-mentioned conventional nuclear fuel gripping apparatus, when two types of PWR fuel assemblies having different widths are mixed, two types of fuel assemblies are handled when the fuel assemblies are handled. Of different widths using the grips of
Since the grips are exchanged according to the WR fuel assembly, there is a problem that the grips replacement time is generated and the fuel handling work is delayed.

The present invention has been made in view of the above circumstances, and it is possible to provide two types of PWR fuel assemblies having different widths.
An object of the present invention is to provide a nuclear fuel gripping device that can be handled with one gripping tool.

[0008]

The nuclear fuel gripping device of the present invention has a gripping device for handling two types of fuel assemblies for pressurized water nuclear power plants (hereinafter simply referred to as fuel assemblies) having different widths. In a vertical direction, the fixing member fixed to the main body of the apparatus is rotatably supported by the fixing member so as to be vertically symmetric with respect to the width of the two types of fuel assemblies, and the upper end portion of the fixing member is uneven. Two pairs of hook claws each having a tapered portion and a lower part, and a guide means that is provided to the fixing member so as to be extendable and contractible, and that positions the fuel assembly during the lifting operation of the fuel assembly, and the guide means. Fixed connecting means, and a plurality of wedges fixed to the connecting member so as to face the concave and convex portions formed on the upper end portions of the hook claws,
When gripping the fuel assembly, the apparatus main body is lowered to insert the guide means into the guide groove formed on the upper end surface of the fuel assembly for positioning, and the cam portion formed at the front end portion thereof. Is lowered along the tapered portion of the hook claw to selectively rotate any one pair of the hook claws of the two pairs of hook claws according to the type of the fuel assembly to be handled, Next, the device main body is lifted to engage with the opening formed at the upper end of the fuel assembly, and drive means for engaging the uneven portion formed at the upper end of each hook claw with the wedge. It is characterized by having.

[0009]

In the nuclear fuel gripping device having the above structure, when gripping the fuel assembly, the body of the nuclear fuel gripping device is lowered by the air cylinder as the driving means, and the guide means is formed on the upper end surface of the fuel assembly. It is inserted into the guide groove and positioned.

At the same time, the cam portion formed at the lower end of the air cylinder descends along the taper portion of the hook claw, so that one of the two pairs of hook claws is selected depending on the type of the fuel assembly to be handled. Any one of the pair of hook claws is selectively rotated, and then the nuclear fuel gripping device main body is raised to engage the tip of the pair of hook claws with the opening formed in the upper end of the fuel assembly. In addition, the concavo-convex portion formed on the upper end of each hook claw engages with the wedge.
As a result, the fuel assembly can be pulled up. Therefore, according to the present invention, it is possible to handle two types of PWR fuel assemblies having different widths with one grip.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show the configuration of the essential parts of the nuclear fuel gripping apparatus according to the present invention. FIG. 1 is a schematic configuration diagram of a main part of a nuclear fuel gripping device, and FIG. 2 is a vertical side view taken along the line I-O-I in FIG.

In these figures, 1 is a cover of the main body of the apparatus.
A fixed member fixed to the fixed member 2, a fixed member fixed to the fixed member 1 and a vertical fixed pin 3 rotatably with respect to the fixed member 2 at a distance corresponding to the widths of the two kinds of fuel assemblies. Two pairs of hook claws 4 which are pivotally supported and have a concavo-convex portion 13 at the upper end thereof and a tapered portion 8 whose lower portion is formed in a tapered shape, 4 are pins fixed to the fixing member 2. , 5 are bushes interposed between the pins 4 and the pin holes of the hook claws 3, and two pairs of hook claws 3 are pivotally mounted at the lower end of the fixing member 1 so as to face each other vertically symmetrically.

Numeral 6 is an air cylinder as a driving means, and a cam portion 7 is formed at the lower end of the air cylinder 6. When the air cylinder 6 is operated in the extension / contraction direction (vertical direction), the cam portion 7 is formed. The hook claw 3 moves up and down along the taper portion 8 of the hook claw 3 so that the hook claw 3 rotates counterclockwise about the pin 4.

Further, 9 is an upper guide pin, 10 is an orientation pin, 11 is a coil spring, 12 is a connecting member,
Reference numeral 14 denotes four wedges fixed to the connecting member 12 through fastening bolts 15 so as to oppose the uneven portion 13 formed at the upper end of the hook claw, and 16 denotes the two pins 4 described above.
A lower guide pin fitted into the side sleeve 17 via the bush 5, and a positioning stopper 18 fixed to the lower end of the spacer 17 interposed between the upper and lower bushes 1,
9 is a spacer, 20 is a PWR fuel assembly, 21 is a PWR
The upper end plate 21 of the fuel assembly 20 has a guide pin hole 26 into which the guide pin 22 is inserted and a grip opening 30. 22 is a guide pin extending below the stopper 18, 23 is a bush, 24 is a claw portion provided at the lower end of the hook claw 3, and 25 is a fastening bolt for fixing the fixing member 2 to the fixing member 1. . A guide means is constituted by the upper guide pin 9, the coil spring 11, the lower guide pin 16, the sleeve 17, the positioning stopper 18, the spacer 19, the guide pin 22, the bush 23 and the spring 28.

Next, the operation of the nuclear fuel gripping apparatus according to the present invention will be described in detail with reference to FIGS. 3 to 6. FIG. 3 is a hook claw 3 as a grip of a nuclear fuel gripping device according to the present invention.
Is above the PWR fuel assembly 20 and FIG. 4 shows that the lower guide pin 16 has the PWR fuel assembly 2
0 is inserted into the guide pin hole 26 of the upper end plate 21, the positional conditions are adjusted, and the whole nuclear fuel gripping device descends and slides.
The hook 17 is seated on the upper surface of the upper end plate 21, and the sleeve 17, the connecting member 12, and the wedge 14 are pushed up, so that the hook claw 3 is rotatable.

FIG. 5 shows the piston 2 of the air cylinder 6.
As the cam 7 descends, the cam 7 descends along the taper portion 8 of the hook claw 3, the hook claw 3 is rotated counterclockwise, and the upper end plate 21 of the PWR fuel assembly 20 can be gripped. FIG. 6 shows the state in which the entire nuclear fuel gripping device according to the present invention is lifted by the external drive source, and the sleeve 1
7 shows a state in which the wedge 14 is engaged with the uneven portion 13 on the upper portion of the hook claw 3 by the coil spring 28 in 7 and the grip of the PWR fuel assembly 20 is completed.

In these figures, the entire nuclear fuel gripping apparatus according to the present invention is lowered from the state shown in FIG. 3 by an external drive source so that the lower guide pin 16 is moved to the PWR fuel assembly 20.
The guide pin hole 26 formed in the upper end plate 21 of the above is approached. At this time, the lower guide pin 16 is pushed down by the extension force of the coil spring 28 in the sleeve 17, and the hook claw 3 cannot engage with the grip opening 30 of the upper end plate 21.

The lowering of the entire nuclear fuel gripping apparatus described above causes the upper end plate 21 of the PWR fuel assembly 20 to relatively rise, and the lower guide pin 16 is inserted into the guide pin 22 of the upper end plate 21 to be positioned. The conditions are met. Since the descent of the entire nuclear fuel gripping device continues from then on, the positioning stopper 18 is next seated on the upper surface of the upper end plate 21, and the wedge 14 fixed to the connecting member 12 via the sleeve 17 is further removed. It is pushed up, and the hook claw 3 becomes rotatable (see FIG. 4).

Next, when the air cylinder 6 operates in the longitudinal direction and the piston 27 of the air cylinder 6 descends,
The cam 7 descends along the taper portion 8 of each hook claw 3, and each hook claw 3 is rotated about its center pin 4 so that the upper end of the PWR fuel assembly 20 is rotated as shown in FIG. It is inserted inside the grip opening 30 formed in the plate 21.

When this state is reached, the hoist on the nuclear fuel gripping device is activated and the wire rope is wound up. Then, the coil spring 11 in the sleeve 17 causes the sleeve 1 to move.
7, the wedge 14 is engaged with the uneven portion 13 of each hook claw 3. When the hoist is further driven, the claws 24 at the tips of the hook claws 3 are moved to the PWR fuel assembly 20.
The PWR fuel assembly 20 can be gripped by contacting the inside of the gripping opening 30 formed in the upper end plate 21 of the PWR fuel assembly 20. While each hook claw 3 is lifting the PWR fuel assembly 20,
Since the wedges 14 engage with the concave and convex portions 13 of the hook claws 3 and are fixed to each other, the hook claws 3 do not rotate even if the cam 7 is operated due to a malfunction of the air cylinder 6. That is,
While the PWR fuel assembly 20 is being lifted, the PWR fuel assembly 20 is prevented from falling even if the air cylinder 6 malfunctions.

In the conventional apparatus, for example, when handling two kinds of PWR fuel assemblies 20 having different widths as shown in FIG.
Since two hook claws 3 of one gripping tool were used when handling one PWR fuel assembly 20, two types of PW
When handling the R fuel assembly at the same time, it was necessary to prepare two types of grips and replace the grips according to the fuel assembly. Therefore, there is a problem that the gripping tool replacement time is required and the fuel handling work is delayed.

On the other hand, according to the present embodiment, when handling the above-mentioned two types of PWR fuel assemblies having different widths, as shown in FIG. 8, the PWR fuel assemblies are provided at different axially symmetrical intervals according to the size of the fuel width. By handling two types of PWR fuel assemblies 20 with two pairs of hook claws 3, one gripping tool can be used, so the gripping tool replacement time is reduced, which affects the treatment process and the operation of the reprocessing plant. Is avoided.

[0023]

According to the present invention, conventionally, four hook claws of one gripping tool are used when handling one PWR fuel, but the hook claws of one gripping tool are axially symmetrical depending on the size of the fuel width. Since two grippers can be handled each time, the gripper replacement time is eliminated, and it is possible to avoid affecting the treatment process and the operation of the reprocessing plant.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a main part of an embodiment of a nuclear fuel gripping device according to the present invention.

FIG. 2 is a vertical cross-sectional side view of each fuel gripping device taken along the line I-O-I in FIG.

FIG. 3 is an explanatory diagram showing an operating state of each fuel gripping device shown in FIGS. 1 and 2.

FIG. 4 is an explanatory diagram showing an operating state of each fuel gripping device shown in FIGS. 1 and 2.

5 is an explanatory diagram showing an operating state of each fuel gripping device shown in FIGS. 1 and 2. FIG.

6 is an explanatory diagram showing an operating state of each fuel gripping device shown in FIGS. 1 and 2. FIG.

FIG. 7 is a plan view of an upper end plate of a PWR fuel assembly,
FIG. 7 (a) shows a wide PWR fuel assembly, and FIG.
(B) is a figure which respectively shows about a narrow PWR fuel assembly.

FIG. 8 is a side view of the upper end plate of the PWR fuel assembly,
FIG. 8 (a) shows a wide PWR fuel assembly, and FIG.
(B) is a figure which respectively shows about a narrow PWR fuel assembly.

9 is a PWR grip portion of the nuclear fuel grip device shown in FIG.
9 is a plan view showing a state in which the fuel assembly is gripped, and FIG.
FIG. 9 (a) shows a wide PWR fuel assembly.
(B) is a figure which respectively shows about a narrow PWR fuel assembly.

10 is a PW grip of the nuclear fuel gripping device shown in FIG.
9 is a front view showing a state in which the R fuel assembly is gripped, and FIG.
FIG. 9 (a) shows a wide PWR fuel assembly.
(B) is a figure which respectively shows about a narrow PWR fuel assembly.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixing member 2 Fixing member 3 Hook claw 4 Pin 5 Bushing 6 Air cylinder 7 Cam part 8 Taper part 9 Upper guide pin 10 Orientation pin, 11 Coil spring 12 Connecting member 13 Uneven part 14 Wedge 15 Fastening bolt 16 Lower part Guide pin 17 Sleeve 18 Positioning stopper 19 Spacer 20 PWR fuel assembly 21 Upper end plate 22 Guide pin 23 Bushing 24 Claw 25 Fastening bolt 26 Guide pin hole 27 Piston 30 Grip opening

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuaki Yoshikawa 3-1-1, Saiwaicho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Tetsuro Wake 3 Saiwaicho, Hitachi-shi, Ibaraki 1-1-1, Hitachi Ltd., Hitachi Plant (72) Inventor, Kunihiko Iwama 3-1-1, Saiwaicho, Hitachi City, Ibaraki Hitachi Ltd., Hitachi Plant

Claims (1)

[Claims] 1. A nuclear fuel gripping device having a grip for handling two types of fuel assemblies for pressurized water nuclear power plants (hereinafter, simply referred to as fuel assemblies) having different widths, and a fixing member fixed to a device body. The two types of fuel assemblies are axially symmetrically rotatably supported by a fixed member at intervals according to the widths of the two types of fuel assemblies, and have an uneven portion at the upper end and a tapered lower portion. 2
A pair of hook claws, a guide means which is provided to the fixing member so as to be capable of expanding and contracting, and which positions the fuel assembly when the fuel assembly is moved up and down, a connecting means fixed to the guide means, and an upper end of each hook claw. A plurality of wedges fixed to the connecting member so as to face the concave and convex portions formed on the portion, and when the fuel assembly is gripped, the main body of the apparatus is lowered to move the guide means above the fuel assembly. Depending on the type of fuel assembly to be handled, by inserting and positioning in a guide groove formed in the end surface and lowering the cam portion formed in the front end portion thereof along the taper portion of the hook claw. Any one of the two pairs of hook claws is selectively rotated, and then the apparatus main body is raised to engage with the opening formed in the upper end of the fuel assembly, and At the top of each hook claw Nuclear gripping apparatus characterized by having a drive means engaging a and made the concavo-convex portion and the wedge.