JPH06324187A - Refueling machine gripper for fast breeder reactor - Google Patents

Abstract

PURPOSE:To enable application even if a rotary plug is not used by providing a direction determining function to a refueling machine itself of a fast breeder reactor, and shortening refueling time. CONSTITUTION:A gripper body 1 is composed of a gripper body upper part 1a supported with a support member and a gripper body lower part 1b which is supported rotatably freely with this gripper body upper part 1a and has a gripper claw 2. A pin 4 installed in an actuator 3 and a holder 5 which is fixed in the gripper body lower part 1b and through which the actuator 3 passes penetratingly and in which a spiral groove 5a is formed to guide the pin 4, are provided, and when the actuator 3 is moved, the gripper claw 2 is rotated according to rotation of the holder 5, and a direction of fuel can be determined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gripper having a bearing function for a fuel exchanger of a fast breeder reactor.

[0002]

2. Description of the Related Art A fast breeder reactor has a faster rate of producing new fissionable substances by absorbing neutrons into a nuclear source material than it consumes nuclear fuel required for a chain reaction by using fast neutrons. Since it is a furnace and heat is taken out from a small core, sodium, which has a good heat transport capacity, is used as a coolant. Since sodium must not come into contact with air, it is sealed in the reactor vessel and the liquid surface is covered with an inert gas. The furnace top lid strictly protects the airtightness and also serves as a shield. However, since it is necessary to replace the fuel without opening the lid, various measures are required.

FIG. 3 is a sectional view of a fuel exchanger of a fast breeder reactor, (A) is a vertical sectional view, and (B) is a sectional view taken along line BB of (A). A large rotation plug 10 and a small rotation plug 11 eccentrically attached to the large rotation plug 10 are arranged above the core, and the small rotation plug 11 has an expandable arm type fuel exchanger 1.
Equipped with 2. At the time of fuel exchange, a telescopic arm type fuel exchanger is mounted on the small rotation plug 11, the fuel exchanger is moved to the vicinity of the fuel to be exchanged, and the fuel is inserted from the upper part of the core for exchange. The telescopic arm refueling machine 12 raises and lowers an internal barrel built into the main barrel by rotating a lifting ball screw shaft, and raises and lowers a stem (not shown) connected to the internal barrel. By raising and lowering this stem,
It is possible to extend and contract the entire arm in the horizontal direction while keeping the gripper body 1 vertical. The fuel of the fast breeder reactor has a substantially hexagonal columnar shape, and the fuel is inserted so that the sides of the surrounding fuel match. Therefore, the surface of the fuel itself has an orientation determining function by unevenness along the longitudinal direction, and this function allows the fuel to be smoothly inserted. As described above, the conventional refueling machine has only the gripping / releasing function for gripping the fuel and the gripper elevating / lowering function for inserting / withdrawing the fuel, and does not have the fuel orientation function.

However, the orientation of the fuel itself may be difficult to insert depending on the combination of the angle of the inserted fuel and the surrounding fuel, which may lead to inability to insert the fuel. Therefore, when the orientation of the fuel itself does not work, as shown in FIG. 3, the rotation of the large rotation plug 10 having the rotation center at the center of the core and the rotation of the small rotation plug 11 having the rotation center at a position eccentric from the center of the core. By combining the rotation, the rotation of the fuel exchanger 12 mounted on the small rotation plug 11 and the extension / contraction of the arm, the orientation is determined when the fuel is inserted.

[0005]

In the conventional refueling machine, when the orientation function of the fuel itself does not work,
Since the large rotation plug, the small rotation plug, and the refueling machine have to be rotated respectively, there is a problem that it takes time to calculate and rotate the angle, and as a result, it takes time to refuel. In the future, the rotary plug will be eliminated and the upper core mechanism will be lifted or removed from the core during refueling to secure a space for refueling, and a single refueling machine will be used to refuel the entire reactor. Is expected to do.

[0006] It is an object of the present invention to provide a fuel exchange gripper of a fast breeder reactor which has an orientation determining function to shorten the fuel exchange time and can be applied even when a rotary plug is not used. .

[0007]

A fast breeder reactor provided with a support member coupled to a ball screw shaft, a gripper main body supported by the support member, and an actuator penetrating the gripper main body and opening and closing a gripper claw. In the refueling machine gripper, the gripper body is composed of an upper part of the gripper body supported by the support member and a lower part of the gripper body rotatably supported by the upper part of the gripper body and provided with the gripper claws, and is attached to the actuator and horizontally. A pin projecting in the direction, a spiral groove that is fixed in the lower part of the gripper body and guides the pin is engraved on the inner surface, and a holder that allows the actuator to penetrate. When moving in the closing direction, open the gripper as the holder rotates. By rotating said gripper while, to achieve the above object.

When the actuator is moved from the position where the gripper is open to the direction where the gripper claw is closed, if the gripper claw is rotated by a predetermined angle while the gripper claw is open, the direction of the fuel can be determined. It is suitable.

[0009]

In the present invention, while the gripper main body is lowered to a predetermined position while gripping the fuel with the gripper claws,
Move the actuator in the direction that the gripper claw closes. At this time, in the operation of the actuator, the claw remains open in a predetermined range. The pin attached to the actuator moves along the spiral groove of the holder attached to the gripper body, and when the holder rotates, the lower part of the gripper body supporting the holder rotates with the gripper open, and the gripper grips the gripper. The fuel being rotated rotates to orient the fuel. The gripper pawls rotate by a defined angle, so when new fuel is oriented and inserted between adjacent fuels and stuck, the gripper pawls rotate by rubbing the fuel's gripping surfaces and the fuel does not rotate. .

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of a fuel exchanger gripper according to an embodiment of the present invention. The gripper body 1 includes a gripper body upper portion 1a supported by a support member coupled with a support member coupled with a screw shaft (not shown), and a gripper body upper portion 1
and a lower portion 1b of the gripper main body which is rotatably supported by a and includes a gripper claw 2. The actuator 3 penetrating the gripper body 1 is moved up and down by a gripper opening / closing mechanism (not shown) to close or open the gripper claw 2. Further, the pin 4 attached to the actuator 3 and protruding in the horizontal direction, and the gripper body lower portion 1b
A holder 5 fixed inside is provided with a spiral groove 5a for guiding the pin 4 on the inner surface, and the actuator 5 is penetrated.

FIG. 2 is a block diagram showing the operating principle of the fuel exchanger gripper shown in FIG. In FIG. 2, the ball screw shaft 7
Is rotated, and the support member 6 connected to this shaft is moved up and down. By moving the support member 6 up and down, the gripper body 1 supported by the support member 6 is moved up and down. The support member 6 includes a spline shaft 8 and a ball screw nut 9 connected to the spline shaft 8 via a gear. The actuator 3 has a ball screw engraved on the top and is connected to the ball screw nut 9. By rotating the spline shaft 8 from the outside, the ball screw nut 9 rotates and the actuator 3 moves up and down, and the tip of the actuator 3 opens and closes the gripper claw 2. When inserting new fuel into place, work in the following order. (1) The gripper body 1 holding the fuel is lowered to a predetermined position in the furnace, and the actuator 3 is moved in the closing direction of the gripper claw 2. At this time, the movement range of the actuator 3 in the gripper claw open state is the range of δ in FIG. 1, and in this range, the gripper claw 2 is in the open state, that is, holding the fuel. (2) The pin 4 of the actuator is the spiral groove 5 of the holder 5.
Although the pin 5 moves in a, the holder 5 engaging with the pin 4 rotates along the spiral groove 5a due to the vertical linear motion of the pin 4, and the lower portion 1b of the gripper body supporting the holder 5 rotates. To do. The rotation angle of the holder is determined by the shape of the spiral groove 5a, and the holder rotates up to 30 °, for example. (3) As a result, the gripper claw 2 supported by the gripper main body lower portion 1b rotates, and the fuel rotates together with the gripper claw 2 to determine the orientation of the fuel. (4) Further, the actuator 3 is moved to close the gripper claw 2 to separate the fuel from the gripper claw 2 and insert the fuel into the furnace.

[0012]

According to the present invention, when the orientation function of the fuel itself does not work effectively during refueling of the fast breeder reactor, the refueling machine gripper holding the fuel is rotated,
Fuel can be smoothly inserted into the furnace. According to the present invention, the orientation of the fuel can be determined by the rotation of the gripper itself without rotating the rotary plug, so that the refueling time can be shortened. The fuel exchanger gripper according to the present invention can be applied even when the rotary plug is not used.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a fuel exchanger gripper according to an embodiment of the present invention.

2 is a configuration diagram showing an operating principle of the fuel exchanger gripper of FIG. 1. FIG.

FIG. 3 is a cross-sectional view of a fuel exchanger of a fast breeder reactor, (A) is a vertical cross-sectional view, and (B) is a cross-sectional view taken along line BB of (A).

[Explanation of symbols]

 1 gripper body 1a gripper body upper part 1b gripper body lower part 2 gripper claw 3 actuator 4 pin 5 holder 5a spiral groove 12 fuel exchanger

Claims (2)

[Claims] 1. A refueling machine gripper for a fast breeder reactor, comprising: a support member coupled to a ball screw shaft; a gripper main body supported by the support member; and an actuator penetrating the gripper main body and opening and closing a gripper claw. , The gripper body is composed of an upper part of the gripper body supported by the support member and a lower part of the gripper body rotatably supported on the upper part of the gripper body and provided with the gripper claws, and is attached to the actuator and extends in the horizontal direction. A pin and a holder fixed in the lower part of the gripper main body and having a spiral groove for guiding the pin on the inner surface and a holder penetrating the actuator are provided, and the actuator is moved from the gripper claw opening position to the gripper claw closing direction. When moving, the gripper remains open as the holder rotates. Refueling machine gripper fast breeder reactor, characterized in that rotating the path pawl. 2. The fuel breeder gripper for a fast breeder reactor according to claim 1, wherein when the actuator is moved from the position where the gripper is opened to the direction where the gripper claw is closed, the gripper claw is kept open and the gripper claw is opened at a predetermined angle. A refueling machine gripper for a fast breeder reactor, which is characterized by rotating the.