JPH0634081B2 - Rotation mechanism of core components - Google Patents

Description

The present invention relates to an apparatus for handling core components of a nuclear reactor,
More specifically, a tooth profile and a protrusion are provided between the gripper that grips and separates the core component and the gripper guide that surrounds the gripper so that the suspended core component can be rotated by the vertical movement of the gripper. The present invention relates to a rotating mechanism of a core component.

[Prior Art] Fuel exchange in a nuclear reactor in a fast breeder reactor will be described with reference to FIG. The core 12 in the reactor vessel 10 is composed of a large number of core components (not shown) such as a fuel assembly. The core components are handled as a unit by the functions of the rotary plug 16 and the fuel exchanger 18 installed in the shield plug 14.

The refueling machine 18 mainly includes a refueling machine body 20 and a holddown arm 22. Refueling machine main body 20
Is for directly handling the core components and has a gripper 24 at the lower end for gripping and separating the core components,
The refueling machine main body 20 as a whole moves up and down. The hold-down arm 22 secures the rigidity of the entire fuel exchanger 18, and as shown in FIG. 5 showing the VV cross section, the hold-down arm 22 wraps around the fuel exchanger main body 20 having low rigidity (however, the fuel exchanger main body 20 And hold down arm 2
2 can move relatively in the vertical direction). A gripper guide 26 is provided around the gripper 24. When the fuel exchanger main body 20 inserts or pulls out core constituent elements, the gripper guide 26 slightly lowers as a whole of the hold-down arm 22 and restrains the surrounding core constituent elements from being lifted up. When the core components are pulled out, the gripper 24 and the drawn-out core components are prevented from swinging.

Grasp by the refueling machine body 20-release function and insertion-
A combination of the pulling-out function, the turning function of the hold-down arm 22 (the gripper 24 inside turns by turning the entire hold-down arm 22), and the turning function of the rotating plug 16 make it possible to use any address of the core. It is possible to pull out a certain core component or insert the core component into any address of the core.

In FIG. 4, reference numeral 28 is a hold-down drive device, 30 is a door valve, 32 is a drive device, 34 is a mount,
Reference numerals 36 respectively indicate the refueling machine main body lifting devices.

[Problems to be Solved by the Invention] In the replacement of the core components in the nuclear reactor performed as described above, there were the following drawbacks.

(1) Since the horizontal cross-section of the fast breeder reactor core components is hexagonal, the new core components can be smoothly inserted into the hexagonal holes from which the old core components have been extracted, with their angles being corrected by themselves. Thus, it was necessary to fabricate a self-orientation mechanism for each core component. In addition, even though it has a self-orientation mechanism, it may not be possible to insert it smoothly, so there has been a demand for forcibly rotating core components.

(2) There are design examples in which a mechanism for rotating core components is added to the fuel exchanger, but in that case, it is configured to rotate the gripper with the drive device on the rotating plug, and therefore the mechanical transmission path Is required, and if it is incorporated, there is a drawback that the fuel exchanger becomes large and complicated.

(3) When the core components are irradiated with neutrons in the core, there is a problem that the material near the center of the core undergoes a material change in particular and the life of the core component itself is determined by the local material change. Therefore, if the core components are appropriately rotated to receive uniform neutron irradiation as a whole, bending and extension on one side of the core components can be made uniform and the in-core life can be extended. No suitable device for rotating has yet been developed.

An object of the present invention is to solve the above-mentioned technical problems of the related art, and to rotate at least a part of the gripper only by machining a simple mechanism in the equipment of the conventional configuration, and thereby the core configuration gripped by the core configuration. It is an object of the present invention to provide a rotation mechanism for a core component that allows the elements to be easily rotated.

[Means for Solving the Problems] The present invention which can solve the above-mentioned technical problems includes a gripper that grips and separates core constituent elements of a nuclear reactor, and a gripper that surrounds the gripper and the gripper is relatively axial in the inside. In a core component handling machine equipped with a movable gripper guide, at least a part of the gripper is rotatable about an axis, and one of the outer peripheral surface of the gripper and the inner peripheral surface of the gripper guide is Two kinds of tooth profiles are formed in two steps, and a protrusion engaging with them is formed on the other side, and the two kinds of tooth profiles rotate in one direction of the circumference when the protrusions move relatively in the axial direction. It is a rotating mechanism of core components having a tilt and a phase difference that cause

Here, as the two types of tooth profiles, for example, there is a configuration in which a triangular wave tooth profile is provided in the upper stage and a large number of island-shaped tooth profiles having a trapezoid in a horizontal direction are arranged on the lower stage side. Here, the tooth profile may be formed on the gripper guide side and the protrusion may be formed on the gripper side, or conversely, the tooth profile may be formed on the gripper side and the protrusion may be formed on the gripper guide side.

[Operation] In the present invention, the protrusion slides along the tooth profile simply by moving the gripper up and down with respect to the gripper guide. Since the two types of tooth profiles are provided with an inclination and a phase difference that cause rotation in one direction of the circumference when the projection relatively moves in the axial direction, the vertical movement of the gripper causes the gripper to move at least partially. Rotates in one direction with respect to the gripper guide.
Therefore, the core component suspended by the gripper can be rotated.

Such a rotation mechanism can also be used as an alternative to the conventional self-orientation mechanism.

[Embodiment] The first embodiment of the rotating mechanism of the core component according to the present invention
Shown in the figure. The gripper 24 is capable of gripping and separating the core component 40 of the nuclear reactor, and at least a part of the gripper 24 is structured to be rotatable about an axis. The gripper guide 26 extends vertically so as to surround the gripper 24, and a notch 27 in the up-down direction is provided over the angular range B so as to face the holddown arm and allow the arm to pass. A first tooth profile 42 and a second tooth profile 44 are formed in upper and lower two steps on the inner peripheral surface of the upper portion of the gripper guide 26, while a protrusion 46 is provided on the outer peripheral surface of the casing of the gripper 24. A developed view is shown in FIG. 2 in order to clarify the shape and the positional relationship between the tooth shapes 42 and 44 and the projection 46.

The first tooth profile 42 provided on the gripper guide side has a triangular wave shape, and the upper side projects inward to restrict the movement of the protrusion 46. A large number of the second tooth profiles 44 are arranged so as to project inward in the form of lateral trapezoids and are separated into islands. On the other hand, the protrusions formed on the gripper 24 have a hexagonal shape and are provided in a large number in one step.
The lateral width of the protrusion 46 is slightly smaller than the distance between the adjacent island-shaped portions of the second tooth profile 44. First tooth profile 42 and second tooth profile 44
Are formed with phase differences δ ₁ and δ ₂ , and their respective inclined surfaces engage with and guide the projection 46. The tooth profiles 42 and 44 are provided so as to relatively function at the upper portion of the gripper guide 26 (the position surrounded by reference numeral A in FIG. 4), that is, the core component withdrawal position or a position slightly higher than that. Has been.

The operation of this rotating mechanism will be described with reference to FIG. First, it is assumed that the gripper 24 is located below the gripper guide 26. When the gripper 24 is raised with respect to the gripper guide 26 in this state as indicated by the arrow, the protrusion 46 abuts the lower inclined surface of the second tooth profile 44. When the protrusion 46 is further pulled up, the protrusion 46 slides up along the lower inclined surface as shown by the arrow. At this time, the gripper 24 rotates, and if the core component is gripped, it also rotates together. When it is further pulled up, the protrusion 46 passes between the second tooth profiles 44 and ascends to reach the first tooth profile 42 as shown by the arrow. When it is further pulled up, as shown by the arrow, the protrusion 46 rises along the slope of the first tooth profile 42, and the gripper 24 rotates at that time. When the protrusion 46 reaches the crest portion of the first tooth profile 42,
The gripper 24 can no longer be lifted. This time, the gripper 24 is lowered as shown by the arrow. Then, the protrusion 46 hits the upper slope of the second tooth profile 44 and descends while rotating along with it. (Indicated by an arrow). Eventually, it will enter between the adjacent islands of the second tooth profile 44 and descend therethrough as indicated by the arrow.

When the gripper 24 is pulled up again in this state, the gripper 24 moves as indicated by the arrow and the arrow and rotates by the next pitch. In other words, by moving the gripper 24 up and down,
The protrusion 46 advances from the arrow to the right as shown by the arrow. This means that the gripper 24, which is integrated with the projection 46 as described above, rotates in the right direction, and if the gripper 24 is gripping the core component 40 at this time, the gripper 24 will move to the core component 40. The target rotation can be given.

Rotation angle θ obtained by one vertical movement of the gripper 24
Can be arbitrarily determined by the arrangement pitch P of the tooth profiles 42 and 44 occupied on the circumference.

FIG. 3 shows a gripper 2 for gripping and releasing the core component 40.
4 shows an example of the structure of No. 4. In the figure, the left half of the center line shows the gripped state, and the right half shows the separated state. Grasp-release of the core component 40 is performed by opening / closing the claw 50. Since the claw 50 is swingably supported by the pin 52, the claw 50 is opened / closed by the vertical movement of a round bar-shaped claw opening / closing rod 54 (mechanically transmitted from a driving device (not shown) on a rotary plug). . The protrusion 46 is formed on the outer peripheral surface of the gripper casing 56.
A sliding rotation mechanism 58 is provided on the upper side. By doing so, the portion below the sliding rotation mechanism 58 can freely rotate while sliding around the pawl opening / closing rod 54 in the circumferential direction.

The preferred embodiment of the present invention has been described above in detail, but the present invention is not limited to such a configuration.
Contrary to the above embodiment, the tooth profile may be provided on the gripper side and the protrusion may be provided on the gripper guide side. In that case, for example, the top and bottom of FIG. 2 may be reversed.

[Effects of the Invention] According to the present invention, as described above, the gripper can rotate around the shaft, and two kinds of tooth shapes and protrusions are formed on the outer peripheral surface of the gripper and the inner peripheral surface of the gripper guide. The tooth profile has an inclination and phase difference that causes rotation in one direction of the circumference when the projection relatively moves in the axial direction, so it can be suspended from the gripper simply by moving the gripper up and down with respect to the gripper guide. Rotation can be imparted to the existing core components. Since this mechanism is extremely simple, it is not necessary to incorporate a mechanical transmission path, and the core component handling machine does not become large or complicated.

In the present invention, since the core components can be caused to rotate, it is not necessary to provide a self-orientation mechanism for each core component, and the structure of the core components can be simplified. Further, even when the core component has a self-orientation mechanism, there is a case where there is an insertion angle that is not self-orientated in the prior art, but the present invention can avoid such a defect.

Furthermore, in the present invention, since the core constituent elements can be easily rotated, it is possible to appropriately rotate the core constituent elements and receive uniform neutron irradiation as a whole to extend the life of the core.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing an embodiment of a rotating mechanism for core components according to the present invention, FIG. 2 is a development explanatory view of its tooth profile and protrusions, and FIG. 3 is a structural view showing an example of a gripper. Is. FIG. 4 is an explanatory diagram showing fuel exchange in the reactor,
FIG. 5 is a V-V arrow view thereof. 10 ... Reactor vessel, 12 ... Reactor core, 18 ... Refueling machine, 20 ... Refueling machine body, 24 ... Gripper, 26
...... Gripper guide, 40 ...... Core components, 42 ......
First tooth profile, 44 ... Second tooth profile, 46 ... Protrusion.

Claims (1)

[Claims] 1. A core component handling machine comprising a gripper for gripping and separating a core component of a nuclear reactor, and a gripper guide surrounding the gripper and having a gripper guide in which the gripper is movable relative to the inside in the axial direction. At least a part of which is rotatable about an axis. Two kinds of tooth profiles are formed in two steps on one of the outer peripheral surface of the gripper and the inner peripheral surface of the gripper guide, and the other is engaged with them. Of the core components, characterized in that they form mating protrusions and the two tooth profiles have an inclination and a phase difference that causes rotation in one direction of the circumference when the protrusions move relatively in the axial direction. Rotation mechanism.