JPH0225476B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a refueling machine for a fast breeder reactor, and more particularly to an arm position monitoring device that prevents the arm of the refueling machine from colliding with a reactor wall or reactor internals during refueling. [Technical Background of the Invention] In fast breeder reactors that generally use metallic sodium as a coolant, the upper shield of the reactor vessel must be opened during fuel exchange because metallic sodium reacts actively with air and water. Unable to change fuel. For this reason, a refueling machine was suspended from the upper shield into the reactor vessel, and the fuel was exchanged using this refueling machine. A fuel exchanger exchanges fuel by gripping the fuel assembly in the core with a gripper installed at the tip of a rotatable arm. By the way, the above-mentioned gripper is configured to move throughout the reactor vessel in order to replace all fuel assemblies, so there is a risk that the tip of the arm may collide with the inner wall of the reactor vessel or reactor internal structures. It was hot. Therefore, the following arm position monitoring device for a refueling machine has been used. Conventional arm position monitoring equipment installs a two-dimensional model of the reactor vessel and fuel exchanger on a control panel outside the reactor vessel, and uses a servo mechanism to ensure that the arm of the model follows the movement of the real arm. Then, a limit switch is attached to the tip of the model arm, and when the limit switch comes into contact with the inner wall of the model reactor vessel or reactor internal structure, an interlock signal is sent to the real fuel exchanger to control the movement of the real arm. It had been stopped. [Problems with the background art] In the conventional arm position monitoring device, a servo mechanism is interposed between the real arm and the model arm, so errors in the servo mechanism cause errors in the position of the model arm, causing the difference between the real arm and the model arm. There was a problem that caused an error in the stopping position of the arm. Another problem was that two-dimensional models of the reactor vessel and fuel exchanger had to be installed, making the entire system larger. [Object of the Invention] The object of the present invention is to provide a fast breeder reactor that can monitor the arm position of a fuel exchanger in a reactor vessel and stop the arm at an accurate position, and that can reduce the size of the entire device. An object of the present invention is to provide an arm position monitoring device for a refueling machine. [Summary of the Invention] The arm position monitoring device for a refueling machine according to the present invention is provided with a coordinate conversion circuit to convert the detected signal of the arm tip position in the fast breeder reactor into coordinates and output it as a digital signal. A comparator is provided that stores the safe operating range of the digital signal, and when the digital signal is within the safe operating range, an operation permission signal is output, and when it is outside the safe operating range, a stop signal is output. The movement of the arm is stopped when the distance is outside the safe range. [Embodiment of the Invention] An embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. 1 is a diagram showing a schematic configuration of a fast breeder reactor, and numeral 1 in the figure is a reactor vessel. A reactor core 2 is configured within this reactor vessel 1,
A fuel assembly (not shown) is housed within the reactor core 2 . The reactor vessel 1 is filled with metallic sodium 3 as a coolant.
The upper part is shielded by a shielding plug 4. and,
A cover gas such as nitrogen gas is sealed between the liquid level of the metallic sodium 3 and the shielding plug 4. The shielding plug 4 includes a fixed plug 4a and a rotating plug 5.
The rotary plug 5 is eccentrically provided to the fixed plug 4a so as to be freely rotatable, and is configured to be rotationally driven by a drive mechanism 5a. A core upper mechanism 6 is attached to the lower surface of the rotating plug 5. The rotary plug 5 is provided with a through hole 6 which is eccentric from the center of rotation and is normally closed. During fuel exchange, a fuel exchanger 7 is inserted into the reactor vessel 1 through the through hole 6 to refuel. configured to perform the exchange. A rotatable arm 7a is attached to the lower end of the fuel exchanger 7, and is configured to be rotationally driven by a drive mechanism 7b. A gripper 8 for gripping the fuel assembly is attached to the tip of the arm 7. The gripper 8 is configured to rotate the rotary plug 5 and the arm 7a of the fuel exchanger 7 and move throughout the inside of the reactor vessel 1. Rotation angle detectors 5b and 7c as position detection mechanisms are attached to the rotary plug 5 and the fuel exchanger 7. The detection signals from both detectors 5b and 7c are transmitted to a coordinate conversion circuit 10 as shown in FIG. 2, and the coordinate conversion circuit 10 converts both rotation angle signals into the tip position of the arm 7a in plane coordinates. It is configured as follows. Coordinate conversion circuit 10
The output signal 10a is transmitted to a comparator 12, and the comparator 12 is composed of a storage circuit 14 such as a ROM, and a comparison circuit 16. The memory circuit 14 divides the movement plane of the tip of the arm 7a, specifies addresses, and stores in advance the safe operation range within the movement plane. The comparison circuit 16 compares the output signal 10a of the coordinate conversion circuit 10 with the read signal from the storage circuit 14, and outputs a stop signal when the output signal 10a is outside the safe operation range, and outputs a stop signal when the output signal 10a is outside the safe operation range. The configuration is such that an operation permission signal is output when the operation is within the range. The output from the comparison circuit 16 is transmitted to the AND circuits 18, 18, and the AND circuits 18, 18 receive operation command signals 20, 2 from the outside.
0 is entered. The AND circuits 18, 18 do not output the operation command signals 20, 20 when the input signal from the comparison circuit 16 is a stop signal, but output the operation command signals 20, 20 when the input signal is an operation permission signal. It is configured. The outputs from the AND circuits 18 and 18 are transmitted to the drive mechanisms 5a and 7b of the rotary plug 5 and the fuel exchanger 7 via drive circuits 22 and 22, respectively. The operation of the structure described above will be explained. As shown in Figure 3, the moving plane of the tip of arm 7a is (X, Y)
Take the coordinates and set the rotation center coordinates of the rotating plug 5 as A ₀
(x ₀ , y ₀ ), center coordinates A ₁ (x ₁ , y ₁ ) of the fuel exchanger 7,
Tip coordinates of arm 7a A ₂ (x ₂ , y ₂ ), A ₀ (x ₀ , y ₀ )
The distance between and A ₁ (x ₁ , y ₁ ) is l ₁ , the length of the arm 7a is l ₂ , the detected value of the rotation angle detector 5b of the rotary plug 5 is θ ₁ , the rotation angle detector of the fuel exchanger 7 Letting the detected value of arm 7c be θ ₂ , the coordinate conversion circuit 10 performs the following calculation to convert the rotation angles θ ₁ and θ ₂ into tip coordinates A ₂ (x ₂ , y ₂ ) of arm 7a. First, the center coordinates A ₁ (x ₁ , y ₁ ) of the fuel exchanger 7 are x ₁ =x ₀ +l ₁ sin θ ₁ y ₁ =y ₀ +l ₁ cos θ ₁ . And the tip coordinates of arm 7a A ₂ (x ₂ ,
y ₂ ) becomes x ₂ = x ₁ + l ₂ sin (θ ₁ + θ ₂ ) y ₂ = y ₁ + l ₂ cos (θ ₁ + θ ₂ ). Furthermore, A ₂ (x ₂ , y ₂ ) becomes x ₂ = x ₀ + l ₁ sin θ ₁ + l ₂ sin (θ ₁ + θ ₂ ) y ₂ = y ₀ + l ₁ cos θ ₁ + l ₂ cos (θ ₁ + θ ₂ ), and A ₂ (x ₂ , y ₂ ) can be calculated as a function of θ ₁ and θ ₂ . The coordinate conversion circuit 10 further includes
The values of x ₂ and y ₂ are digitally converted and output as an output signal 10a. As shown in FIG. 4, the memory circuit 14 divides the (X, Y) coordinates of the moving plane of the tip of the arm 7a into 4-bit digital signals, and specifies the moving plane as an address, and stores the arm 7a as shown in the shaded area.
The address of the safe operating range is memorized. The comparison circuit 16 compares the read signal from the storage circuit 14 and the output signal 10a according to the program shown in the table, and when the output signal 10a is within the safe operation range, it outputs logic 1 as an operation permission signal and outputs the output signal. When 10a is outside the safe operating range, it outputs a logic 0 as a stop signal. In the table, inputs ²⁰ to ²³ are 4-bit digital signals for the X coordinate, and inputs ²⁴ to ²⁷ are 4-bit digital signals for the Y coordinate.

【table】

〔Effect of the invention〕

According to the present invention, it is possible to monitor the arm position of a fast breeder reactor fuel exchanger and accurately stop the arm at a position where the tip of the arm should not enter.
Moreover, the effects are great, such as being able to provide an arm position monitoring device that allows the entire device to be made smaller.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view showing a schematic configuration of a fast breeder reactor, Fig. 2 is a configuration diagram showing an embodiment of the present invention, and Fig. 3 is a coordinate showing the arm tip position A ₂ (x ₂ , y ₂ ). FIG. 4 is a plan view showing address designation of the memory circuit 14. 5b...first rotation angle detector, 7c...second rotation angle detector, 10...coordinate conversion circuit, 12...
Comparison section, 14... Memory circuit, 16... Comparison circuit,
18...AND circuit, 5a, 7b...Drive mechanism.

Claims (1)

[Claims] 1 A first rotation angle detector that detects the rotation angle of a rotating plug of a fast breeder reactor, a second rotation angle detector that detects a rotation angle of an arm of a refueling machine mounted on the rotating plug, and both of these. a coordinate conversion circuit that detects the arm tip position of the fuel exchanger based on the detection signal from the detector and converts the arm tip position into a coordinate signal and outputs the coordinate signal; and a comparator that compares whether or not the arm tip position is within a pre-stored safe operation range and sends a signal to permit a fuel exchange operation only when the arm tip position is within the safe operation range. An arm position monitoring device for a fuel exchanger, characterized in that: