JPH02249998A - Refueling machine for fast breeder reactor - Google Patents

Abstract

PURPOSE:To directly execute the shuffling in a reactor core by transferring temporarily fuel to an in-pile storage pot and without changing it with other fuel by allowing a refueling machine itself to have a rotary function by a gripper outer cylinder rotation driving device. CONSTITUTION:On a rotary plug for covering the upper part of a nuclear reactor, a door valve 5 and a hold-down mechanism 6 are placed, on which a refueling machine supported by a rack base 4 is attached. In this state, the refueling machine is positioned in a position of a change reactor core by a rotation of the rotary plug, and thereafter, a gripper driving part 2 and a gripper outer cylinder 3 descends in the rack base 4, and also, by opening and closing a claw of the tip of the outer cylinder 3, fuel is gripped. In this state, the driving part 2 and the outer cylinder 3 are allowed to ascend and the fuel is drawn out of the reactor core. Subsequently, when a gripper outer cylinder rotation driving device consisting of the driving part 2, a motor 1, and a first and a second gears 8, 9 is driven in a state that the fuel remains gripped, a gripper driving part casing 12 and the outer cylinder 3 rotate, and the fuel also rotates. Thereafter, these are allowed to descend and held in the reactor core. In such a way, shuffling of fuel is executed.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a fuel exchanger for exchanging fuel in a fast breeder reactor that uses liquid metal as a coolant.

[Conventional technology]

This type of fuel exchanger positions the fuel exchanger at a predetermined position in the core by rotating a dual-rotation plug consisting of a large-rotation plug that covers the top of the reactor and a small-rotation plug that is installed eccentrically, and then uses a gripper that passes through the rotary plug. Fuel exchange machines that grab and exchange fuel are known. Inside a nuclear reactor, neutrons are emitted from the center of the core toward the outer radius, so the inner radius of the fuel toward the core receives more neutron radiation, and the outer radius receives less neutron radiation than the inner radius. Shuffling is the act of changing the position of fuel during use in order to make more effective use of the fuel in the reactor, such as rotating the fuel 180 degrees or shuffling it between the inner fuel rods and outer fuel rods in the radial direction of the reactor. Replace.

[Problem to be solved by the invention]

However, in the above-mentioned fuel exchange machine, the gripper does not rotate when performing shuffling, so it is necessary to temporarily transfer the fuel to the in-core storage pot, grab other fuel in the in-core storage pot, and transfer it to the reactor core again. Met. For this reason, there was a drawback that shuffling time was long. In order to shorten the shuffling time, the problem can be solved by stopping the work of replacing fuel into the in-furnace storage pot and by equipping the fuel exchanger itself with a rotating mechanism. An object of the present invention is to provide a fuel exchanger that can directly shuffle fuel in the reactor core without first transferring the fuel to an in-core storage pot and replacing it with other fuel.

[Means to solve the problem]

The above object includes a gripper drive unit casing attached to a gripper outer cylinder that holds a gripper, a first gear attached to the head of the gripper drive unit casing, and an outer cylinder that rotatably supports the drive unit casing. a gripper rotation drive device comprising: a gripper drive unit consisting of a gripper drive unit; an electric motor disposed on an upper part of a pedestal for raising and lowering the gripper drive unit; and a second gear connected to the electric motor and meshing with the first gear; This problem is solved by rotating the gripper and fuel by driving the gripper rotation drive device while gripping the fuel. Further, a gripper drive unit casing rotatably supports a gripper outer cylinder holding a gripper, a first gear attached to an upper part of the gripper outer cylinder, an electric motor disposed at a lower part of the gripper drive unit casing, and this electric motor. It is preferable to include a gripper rotation drive device including a second gear connected to the first gear and meshing with the first gear, so as to rotate the gripper and the fuel while gripping the fuel with the gripper. The gripper rotation drive device includes an electric motor installed in the gripper drive casing and a ball spline driven by the electric motor, and a claw operation shaft supported in the ball spline so as to be movable up and down and operates the gripper. an upper gripper outer cylinder that is attached to the gripper drive unit casing and allows the claw operation shaft to pass through the upper gripper outer cylinder; It is preferable that the gripper has a lower part of the outer cylinder connected by a key, and the gripper and the fuel are rotated while the gripper grips the fuel.

[For use]

According to this invention, the gripper drive unit casing or the gripper outer cylinder is rotatable, and a gripper outer cylinder rotation drive device that rotates the gripper outer cylinder holding the gripper is provided, or the gripper outer cylinder is divided into two and the lower gripper outer cylinder is rotated. Since the cylinder is rotatable and a gripper rotation drive device is provided to rotate the lower gripper outer cylinder, the gripper and the fuel can be rotated while the gripper is gripping the fuel, and the fuel can be shuffled in the core.

【Example】

The present invention will be described in detail below based on the drawings. FIG. 1 is an assembly diagram of a fuel exchanger according to an embodiment of the present invention. The upper part of the reactor is covered with a rotating plug, and a door valve 5 and a hold-down mechanism 6 are placed on top of this rotating plug, and supported by a pedestal 4. Install the refueling machine. The rotary plug rotates to position the refueling machine at the core to be replaced. The gripper drive unit 2 and the gripper outer cylinder 3 descend within the frame 4, and the claw 15 attached to the tip of the gripper outer cylinder 3 is opened and closed by a claw opening/closing mechanism to grasp the fuel. In this state, the gripper drive unit 2 and the gripper outer cylinder 3 are raised to pull out the fuel from the core.
It is a sectional view of B. The gripper drive unit 2 includes a gripper drive unit casing 12 attached to a gripper outer cylinder 3 that holds a gripper, and a first gripper drive unit casing 12 attached to the head of the gripper drive unit casing 12.
It consists of a gear 8, an outer cylinder 13 and a bearing 14 that rotatably support the gripper drive unit casing 12, and wheels 11 attached to the outer cylinder 13. The gripper outer cylinder rotation drive device includes the gripper drive unit 2, an electric motor 1 disposed on the upper part of a pedestal 4 for raising and lowering the gripper drive unit 2, and a second gear connected to the electric motor 1 and meshing with the first gear 8. It consists of. In FIG. 3, the gripper drive unit casing 12 is rotatably held by the outer cylinder 13 via a bearing 14.
The gripper drive unit 2, which is in contact with the rail 10 of the pedestal 4 through wheels 11, is suspended from the head of the pedestal 4 by a rope and is raised and lowered along the rail 10. The electric motor 1 is fixed to a frame 4 and connected to a second gear 9 via a speed reducer 7. FIG. 3 shows a state in which the first gear 8 of the gripper drive unit 2 and the second gear 9 of the electric motor 1 are meshed. When the gripper drive unit 2 is raised and the electric motor 1 is driven with the first gear 8 of the gripper drive unit meshing with the second gear 9 connected to the electric motor 1, the gripper drive unit casing 12 and the gripper outer cylinder 3 are driven. As the gripper rotates, the fuel gripped by the gripper also rotates. Thereafter, the gripper drive unit 2 and the gripper outer cylinder 3 are lowered to store the fuel in the reactor core. mosquito(
Perform fuel shuffling as follows. FIG. 4 is an assembled view of a fuel exchanger according to another embodiment of the present invention, and FIG. 5 is a detailed view of the lifting/lowering portion of the fuel exchanger of FIG. 4. In FIGS. 4 and 5, the same parts as in FIGS. 1, 2, and 3 are designated by the same numbers. The upper part of the nuclear reactor is covered with a rotating plug, a door valve 5 and a hold-down mechanism 6 are mounted on the rotating plug, and a fuel exchanger supported by a frame 4 is attached thereon. The rotary plug rotates to position the refueling machine at the core to be replaced. The gripper drive unit casing 12 and the gripper outer cylinder 3 descend inside the pedestal 4, and then the gripper outer cylinder 3
The claw 15 attached to the tip is operated by a claw operation shaft 16 to open and close the claw 15 to grasp the fuel. In this state, the gripper drive unit casing 12 and the gripper outer cylinder 3 are raised to extract fuel from the core. The gripper outer cylinder rotation drive device includes a gripper drive unit casing 12 that rotatably supports a gripper outer cylinder 3 holding a gripper via a bearing, a first gear 8 attached to the upper part of the gripper outer cylinder 3, and a gripper outer cylinder 3. Drive part casing 12
It consists of a second gear 9 connected to an electric motor 1 disposed at the lower part of the motor and meshing with a first gear 8. The gripper drive unit casing 12 is suspended from the head of the pedestal 4 with a rope and is moved up and down along a rail (not shown). FIG. 5 shows the state in which the gripper claws 15 are suspended in the reactor core, and the claw operating shaft 16 is lowered by an electric motor (not shown) installed inside the gripper drive unit casing 12, and the claws 15 are opened. The fuel is gripped, and the gripper drive unit casing 12 and the gripper outer cylinder 3 are placed on the frame 4. The fuel is lifted from the head of the reactor using a rope and pulled out of the reactor core. When the electric motor 1 of the gripper outer cylinder rotation drive device is driven with fuel being extracted from the core, the second gear 9 connected to the electric motor 1 and the second gear 9 and the gripper outer cylinder 3 are driven.
The first gear 8 attached to the upper part of the gripper meshes with the first gear 8 to rotate the gripper outer cylinder 3. When the gripper outer cylinder 3 rotates, the fuel gripped and suspended by the gripper rotates. After rotating the fuel, shuffling the fuel can be performed by putting the fuel back into the core. FIG. 6 is an assembly diagram of a fuel exchanger according to another embodiment of the present invention, FIG. 7 is a detailed diagram of the gripper drive section of FIG. 6, and FIG.
The figure is a detailed view of the gripper barrel of FIG. 6. In Figures 6 to 8, the upper part of the reactor is covered with a rotating plug;
Above this rotating plug is the door valve 5. A hold-down mechanism 6 is mounted, and a fuel exchanger supported by a pedestal 4 is attached thereon. The rotating plug rotates to position the refueling machine at the core p position to be replaced. The gripper drive unit 2 and the gripper outer cylinder 3 descend within the pedestal 4. When the gripper descends within the frame 4 and reaches the fuel top of the core, the vertical drive device 20 is driven to move the claw operation shaft 16 up and down to open the claws 15 and grasp the fuel. The gripper rotation drive device includes a gripper drive unit casing 1
It consists of an electric motor 1 installed in a motor 2, and a ball spline 17 driven by the electric motor via a reduction gear. In the embodiment of FIG. 6, the gripper sleeve 3 is divided into an upper gripper sleeve 3a and a lower gripper sleeve 3b. In FIGS. 7 and 8, the gripper drive unit 2 includes a claw operating shaft 16 that is vertically movably supported in a ball spline 17 and that operates the gripper, and a gripper drive unit casing 12 through which the claw operating shaft 16 passes. An upper gripper outer cylinder 3a attached to the upper gripper outer cylinder 3a and a lower gripper outer cylinder 3b rotatably disposed below the upper gripper outer cylinder 3a and connected by a claw operation shaft 16 and a key 19 are connected. Since the claw operation shaft 16 is moved up and down by the ball screw 18,
At this time, the ball spline 17 is a mechanism that can slide up and down. When the electric motor 1 is rotated, the pawl operating shaft 16 rotates via the ball spline 17, and the rotation of the pawl operating shaft 16 is further transmitted to the key 19. The lower gripper outer cylinder 3b is rotated by the rotational force transmitted to the key 19, the claws 15 pinned to the lower gripper outer cylinder 3b are also rotated at the same time, and the fuel hanging from the claws 15 in the furnace is also rotated. After rotating the fuel, the gripper is lowered and the fuel is placed into the furnace again, thereby shuffling the fuel.

【Effect of the invention】

According to claims 1, 2 and 3 of the present invention, the gripper drive unit casing or the gripper outer cylinder is rotatable, the gripper outer cylinder is rotated by a gripper outer cylinder rotation drive device, and the fuel exchanger itself is Since it has a rotation function, it is possible to shuffle the fuel in the core by rotating the gripper and the fuel while gripping the fuel with the gripper. According to claim 4 of the present invention, the lower gripper outer cylinder is rotatable, the lower gripper outer cylinder is rotated by a gripper rotation drive device, and the gripper and the fuel are rotated while the gripper grips the fuel. , fuel shuffling can be performed in the reactor core. As described above, according to the present invention, it is not necessary to temporarily transfer the fuel to the in-furnace storage pot as in the conventional method, and the shirting time can be significantly shortened.

[Brief explanation of drawings]

FIG. 1 is an assembly diagram of a fuel exchanger according to an embodiment of the present invention;
Figure 2 is a sectional view taken along line A-A in Figure 1, and Figure 3 is a cross-sectional view taken along line B-- in Figure 2.
B sectional view, FIG. 4 is an assembly diagram of a fuel exchanger according to another embodiment of the present invention, FIG. 5 is a detailed view of the lifting and lowering portion of the fuel exchanger of FIG. 4, and FIG. 6 is another embodiment of the present invention. FIG. 7 is a detailed view of the gripper drive unit shown in FIG. 6, and FIG. 8 is a detailed view of the gripper outer cylinder shown in FIG. 6. 1: Electric motor, 2 Nigeripper drive unit, 3 Nigeripper outer cylinder,
3a: Upper gripper outer cylinder, 3b: Lower gripper outer cylinder,
4: Frame, 8: First gear, 9: Second gear, 12; Gripper drive unit casing, 13: Outer cylinder, 15: Claw, 16
: Claw operation shaft, 17: Ball spline, 9: Key, 20: Vertical drive device. fig fig fig fig fig fig fig fig fig fig fig fig fig fig fig fig fig fig fig fig fig fig fig fig fig.

Claims (1)

[Claims] 1) In a fuel exchange machine for exchanging fuel of a fast breeder reactor,
A gripper outer cylinder rotation drive device that rotates a gripper outer cylinder holding a gripper is provided, and the gripper rotation drive device is driven while the gripper is gripping the fuel to rotate the gripper and the fuel, and shuffling of the fuel is performed. A fast breeder reactor refueling machine that is characterized by: 2) In the fuel exchanger according to claim 1, the gripper outer cylinder rotation drive device includes a gripper drive part casing attached to a gripper outer cylinder holding a gripper, and a first gripper drive part casing attached to the head of the gripper drive part casing. a gripper drive unit comprising a gear, an outer cylinder rotatably supporting the gripper drive unit casing, an electric motor disposed on an upper part of a pedestal for raising and lowering the gripper drive unit, and the first gear connected to the electric motor. A refueling machine for a fast breeder reactor, comprising: a second gear meshing with the first gear; 3) In the fuel exchanger according to claim 1, the gripper outer cylinder rotation drive device includes a gripper drive unit casing that rotatably supports a gripper outer cylinder that holds a gripper;
The gripper is characterized by comprising a first gear attached to the upper part of the gripper outer cylinder, an electric motor disposed at the lower part of the drive part casing, and a second gear connected to the electric motor and meshing with the first gear. Fast breeder reactor refueling machine. 4) In a fuel exchange machine that exchanges fuel in a fast breeder reactor,
A gripper rotation drive device consisting of an electric motor installed in a gripper drive casing and a ball spline driven by the electric motor, and a claw operation shaft supported vertically movably in the ball spline and operating the gripper. an upper gripper outer cylinder that is attached to the gripper drive unit casing and allows the claw operation shaft to pass through the upper gripper outer cylinder; and a lower gripper outer cylinder connected by a key, and the gripper rotation drive device is driven while the gripper grips the fuel to rotate the gripper and the fuel, thereby shuffling the fuel. Fast breeder reactor refueling machine.