JP2544387B2 - Fast fuel change method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fuel exchanger for a nuclear power plant, and is particularly suitable for high-speed transfer of fuel assemblies by four-dimensional simultaneous control of XYZO. Refueling method.

[Conventional technology]

The conventional control method of a fuel exchanger is a system that is manually operated from an operation box on a trolley, and its traveling and traverse are operated independently in driving.

After that, AEG in West Germany developed an automated system, which was partially automated by the operation from the operator console on the trolley, and the simultaneous control method for traverse has been adopted. Nakatsuta. Therefore, as described in JP-B-58-19238, in a system for simultaneously controlling traveling and traverse, a control route from the current position to a target position is automatically calculated in a traverse limit loop having a complicated shape, There is an application for a control method for calculating speed command signals for traveling and traversing, but it is limited to two-dimensional simultaneous control of traveling and traversing. Regarding multi-dimensional simultaneous control considering speedup and time reduction of fuel transfer time, , I was not considered.

[Problems to be solved by the invention]

The above-mentioned prior arts are all considered only to shorten the fuel transfer time by horizontal two-dimensional simultaneous control in the pool and the core, and do not consider the simultaneous control of the lifting and rotating operations of the fuel gripping device. The effect of shortening the transfer time by the simultaneous control of X-Y-Z-O cannot be obtained.

An object of the present invention is to solve the above problems by enabling multidimensional simultaneous control for the above problems.

[Means for solving problems]

Means for achieving the above-mentioned object are a movable carriage configured to be movable between a core pool and a fuel storage pool of a nuclear power plant on an X-Y axis plane, and attached to the movable carriage and perpendicular to the plane. A fuel gripping device that is moved in the Z-axis direction, a rotating device that is attached to the moving carriage to rotate the fuel gripping device in the O direction around the Z-axis, and the moving carriage, the fuel gripping device, and the rotating device. In an automatic refueling machine which has a drive means for moving in the axial direction and which automatically carries out fuel transfer across a core and a fuel storage pool by setting a target position, the lower end of the fuel gripping device is on a flat surface. Is in the region of the core position of the core pool, and the first steady rest position when the fuel gripping device is unloaded is lower than the second steady rest position when loaded. On the condition that the lower end is above the first steady-state position when there is no load and above the second steady-state position when there is a load on a vertical plane perpendicular to the plane. , X in the drive means
A high-speed fuel exchange method is characterized in that the respective axes of Y-axis, Z-axis, and O-axis are simultaneously applied to the rotating device so that the lower end of the fuel gripping device approaches a target position in the shortest distance.

[Action]

When the fuel gripping device does not hold a load such as fuel and there is no load, the lower end of the fuel gripping device is located when the lower end is in the region of the core position of the core pool and above the first steady position. , Refueling machine is X
The fuel gripping device that receives the control of each axis, Y-axis, Z-axis, and O-axis at the same time, and the trajectory projected on the vertical plane to the first steady position moves diagonally and moves the shortest distance to approach the target position. When a load such as fuel is being loaded, the lower end of the fuel gripping device has a lower end when the lower end is in the region of the core pool above the reactor and above the second steady rest position. Receives the control of X-axis, Y-axis, Z-axis, and O-axis at the same time, and the trajectory projected on the vertical plane to the first steady-state position becomes oblique and moves at the shortest distance to approach the target position. Make up.

〔Example〕

 An embodiment of the present invention will be shown below.

FIG. 5 (A) shows a cross-sectional view of the boiling K-type reactor core. In this figure, 36 is a fuel assembly, 40 is a control rod, 41
Indicates LPRM (local output detector).

Further, as shown in FIG. 5B, the four fuel assemblies 36 surrounding one control rod 41 constitute a cell. The handle 36A of the four fuel assemblies 36 faces the control rod.

The operation of the reactor reduces the reactivity of the core, so old fuel assemblies must be replaced with new fuel assemblies on a regular basis. This operation period is called a cycle, and the new fuel is exchanged at the end of each cycle. The number of fuel assemblies in the core is about 800 in a 1.1 million KW class power generation reactor, and it is necessary to replace the fuel assemblies for 1/4 to 1/3 cores at each regular inspection. This kind of refueling work is a critical path during a reactor outage, and shortening the refueling time leads to a reduction in the number of days required for a nuclear power plant to be inspected. It leads to an improvement in the rate.

Next, the control method of the conventional fuel exchanger will be described below.

First, an example of the fuel changer will be described with reference to FIG. The refueling machine is composed of a traveling carriage 1, a traverse carriage 2, a graph 4, a telescopic tube 3 and a hoist 5. The traveling vehicle 1 is moved by a drive motor 8 on a pair of rails 6 installed on both sides of a core pool 32 and a fuel storage pool 30 described later. The traverse vehicle 2 has a group 4, a telescopic tube 3 and a hoist 5, and is moved by a drive motor 9 on a pair of rails 7 installed on the traveling vehicle 1. The grapple 4 is moved up and down by the hoist 5 and is rotated by the drive motor 11 for adjusting the fuel loading angle. Further, this glass 4 is attached to the lower ends of several expansion tubes 3. Hereinafter, the moving direction on the traveling carriage 1 is referred to as X, the moving direction of the traverse carriage 2 is referred to as Y, the up and down movement of the glass 4 is referred to as Z, and the rotation is referred to as O.

The trolley, traverse trolley and hoist of the refueling machine are driven by a DC motor.

FIG. 7 shows a block diagram of the traverse portion of the device to which the control method in the prior art is applied. In FIG. 7, 8 is a traveling carriage drive motor, 9 is a traverse carriage drive motor, 51 is a speed control device, and 50 is an arithmetic processing device (control computer or equivalent control device).

The operator inputs the target fuel position ID number to the arithmetic processing unit 50 as the request number 53. The arithmetic processing unit 50 takes in position signals corresponding to the traveling carriage current position X ₁ and the transverse carriage current position Y ₁ , and calculates a speed command signal 55 for the traveling carriage and the transverse carriage from the relationship between the current position and the target position. The speed command signal 55 is input to the speed control device 51. The speed controller 51 compares the speed command signal 55 with the speed feedback signal 56,
In order to reduce this difference, the circuit voltage of the DC motor to be controlled is controlled so that the speed of the truck follows the command signal for positioning.

The above-mentioned conventional control method aims at shortening the time required from the current position to the target position, and is an XY simultaneous control method.Time reduction by simultaneous control of Z and O is considered. Nakatsuta.

Next, a preferred embodiment of the present invention will be described. A high-speed fuel exchange method will be described with reference to FIGS. The mechanical system of the refueling machine is as described above in FIG. Therefore, a position signal indicating the amount of movement of X, Y, Z, O is detected by a synchro oscillator (not shown) attached to each drive shaft and input to the process input / output device 13. The process input / output device 13 converts this signal into a digital signal and outputs it to the computer, that is, the central processing unit 14. Central processing unit 14
Is based on an operator's command from the operator console 16, compares the position to be moved with the current position, calculates the drive amount, and outputs the operation signal to the process input / output device.
Drive motors 8, 9 and 1 via 13 and control panel 12
Give to 0,11.

The computer system includes a central processing unit 14, a process input / output unit 13, an operator console 16, and peripheral devices such as a storage unit 15, an I / O typewriter 18, a floppy disk, and a reading unit 19. ing.

In addition, the position state of the fuel changer shown in FIG.
Traveling vehicle above the furnace (position sandwiched by two two-dot chain lines parallel to the Y axis in Fig. 2), traverse vehicle gate passing position (parallel to the X axis in Fig. 2 and fuel storage pool 30, gate 31) And the position of the alternate long and two short dashes line passing through the core pool 32), the upper limit position of the grapple, the intermediate position, the seating position, the fuel storage pool side, the core side The position detection means detects the horizontal traveling movement permission position with no load in the fuel storage pool, the horizontal traveling movement permission position with no load in the core, and the lateral movement movement permission position with core in-load. , To the central processing unit 14 via the process input / output unit 13. The computer uses these signals for positioning control and monitoring (the Z direction indicates the bottom end position of the glass).

The contents of the automatic operation of the refueling work in the present invention will be specifically described with reference to FIGS. 2 and 3 (A) and FIG. 3 (B).

The refueling machine is installed across the fuel storage pool 30 and the core pool 32. When the fuel is exchanged, the gate 31 is opened, and water is filled between the fuel storage pool 30 and the core pool 32. A fuel rack 33 is installed in the fuel storage pool 30.

Normally, refueling work is performed between the fuel rack 33 and the core 34. Therefore, the computer stores in advance the X, Y, Z, O control routes corresponding to the X, Y ID numbers of the fuel rack 33 and the core 34, and the fuel loading status at each position.

Hereinafter, the case where the fuel is transferred from the position P having the fuel rack 33 to the position Q having the core 34 will be described as an example.

The coordinates at the current position P of the refueling machine are X _P , Y _P , Z _P , O _P
The coordinates of _Q , which is the purpose of transfer, are X _Q , Y _Q , Z _Q , and Q _Q.

The operator first sets the XY ID number of the target position Q using the operator console 16. Next, the computer is requested to determine whether or not automatic activation is possible. When the automatic start is permitted, the start push button is pressed to request the start of the automatic operation. When the start-up is started, the Z-rise control is first performed, and the Z-stop is temporarily stopped at the upper limit position.

Next, XY simultaneous control is performed. In XY control, reference points b and c are set in advance, and the computer uses P → b → c →
A straight route passing through Q is calculated, and the driving amounts of X and Y are output so as to ride on this route. That is, sequentially b, c, Q
The deviations ΔX and ΔY from the current position are calculated with the target position as the target position, the larger deviation is the constant speed, and the other is the speed calculated by the deviation ratio. Therefore, in the condition, the ON signal of the limit switch becomes a condition, and the O control and the Z (down) control are simultaneously started. In this case, X and Y control is also performed at the same time. Even in O control, the deviation ΔO between O _P and O _Q is calculated and the drive amount is output. In the Z (lowering) control, the limit switch (the position for lateral traveling movement during core load) is
It continues until it turns off. Next, when the positioning is completed at the target position Q, the shake waiting control is performed at, and the Z (lowering) control is performed at the end of the shake waiting control, the fuel assembly 36 is inserted into the core 34, and the seating position is set. Stop at

As described above, in the automatic operation, the control of to is one cycle and is continuously performed.

Further, as a control pattern, there is a pattern in which the fuel is taken from the fuel storage pool 30 to the core 34, but as shown in the control flow of FIG.

As a safety measure, the X, Y, Z movement restriction logic is considered as shown in FIG.

Therefore, by adopting this replacement method, X, Y, Z,
Simultaneous control of O is possible, which has a great effect on shortening the refueling time.

Further, as a modified example of the above-described embodiment, the same control system can be adopted for a fuel changer provided with a plurality of gripping devices, and a great effect can be obtained in reducing the refueling time.

〔The invention's effect〕

According to the present invention, the movement of the fuel assembly in the pool and the core, and the operation of grabbing the fuel assembly, X, Y,
Since four-dimensional simultaneous control of Z and O becomes possible, by adopting the present invention, the fuel exchange work time is about 10 minutes as compared with the conventional time, which is one step in the related art.
It can be shortened to 1 minute 10 seconds, and the effect of 1 regular inspection is 1.1 million K
It is possible to reduce the number of replacement days of W class results of 12 days by 1 day, which is a great effect in shortening the regular inspection period.

[Brief description of drawings]

FIG. 1 is an embodiment of the present invention, and is an overall configuration diagram of a mechanical system and a control system of a refueling machine. FIG. 2 is a plan view of a reactor building top floor and a sectional view of the reactor building. FIG. 3 (A) is a flow chart showing the control method of the present invention, in which the fuel in the pool is moved to the core.
FIG. 3 (B) is a flow chart for taking the fuel assemblies from the pool to the core, FIG. 4 is a XYZ movement restriction logic diagram, and FIG. 5 (A) is a plan view of the core. FIG. 5 (B) is an enlarged view of part B of FIG. 5 (A), FIG. 6 is an explanatory view of a conventional fuel changer, and FIG. 7 is a configuration and function of a conventional control method. It is a figure explaining. 1 ... Traffic trolley, 2 ... Transverse trolley, 3 ... Expansion tube, 4 ...
… Grapples, 5 …… Hoists, 6 …… Traveling rails, 7
…… Traverse rail, 8 …… Truck carriage drive motor, 9 …… Traffic carriage drive motor, 10 …… Grapples drive motor (elevation), 11 …… Grapples drive motor (rotation), 12 …… Control panel, 13 …… Process input / output device, 14 ... Central processing unit, 15 ... Storage device, 16 ... Operator console, 17
...... I / O typewriter, 18 …… Logging typewriter, 1
9 …… Paper tape reader, 20 …… Relay board, 30 …… Fuel storage pool, 31 …… Gate, 32 …… Core pool, 33 ……
Fuel rack, 34 ... core, 35 ... pressure vessel, 36 ... fuel assembly, 40 ... control rod, 41 ... LPRM (local output detector), 50 ... arithmetic unit, 51 ... speed control unit , 52 ... speed detector, 53 ... target cell request signal, 54 ... position signal,
55 …… Speed command signal, 56 …… Speed signal.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuro Wake 3-1-1, Saiwaicho, Hitachi City Inside the Hitachi factory, Hitachi, Ltd. (72) Inventor Akira Koizumi 3-1-1, Saiwaimachi, Hitachi City Hitachi, Ltd., Hitachi, Ltd. (72) Inventor, Mitsuhiro Kumazawa 3-2-1, Saiwaicho, Hitachi, Ltd., within Hitachi Engineering Co., Ltd. (56) References JP-A-52-137589 (JP, A) JP-A-SHO 61-149897 (JP, A)

Claims (1)

(57) [Claims] 1. A moving carriage configured to be movable between a core pool and a fuel storage pool of a nuclear power plant on an X-Y axis plane, and a Z-direction perpendicular to the plane mounted on the moving carriage. A moving fuel gripping device, a rotating device attached to the moving carriage for rotating the fuel gripping device in the O direction around the Z axis, and moving the moving carriage, the fuel gripping device, and the rotating device in the respective axial directions. In an automatic refueling machine having a driving means and automatically carrying out fuel transfer across a core and a fuel storage pool by setting a target position, when the lower end of the fuel gripping device is on a plane, Being in the region of the on-furnace position, and setting the first steady rest position when the fuel gripping device is unloaded lower than the second steady rest position when loaded The X-axis of the drive means is provided on the condition that the lower end of the perpendicular plane is above the first steady rest position when there is no load, and above the second steady rest position when there is a load. , A Y-axis, a Z-axis, and O-axis control to the rotating device at the same time, and the lower end of the fuel gripping device is brought close to a target position at the shortest distance.