JPH0762718B2 - Refueling machine control method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control method for a fuel exchanger for a nuclear power plant, and more particularly, in a fuel gripping device in which a fuel body and a gripping mechanism are not fixed, by transferring the fuel body. The present invention relates to a control method suitable for early damping of shake.

[Conventional technology]

The steady rest of the conventional fuel gripping device is Japanese Patent Publication Sho 61-222.
As described in No. 79, the shake was damped by the steady rest installed on the top of the fuel gripping device. However, in the case of this device, in the fuel gripping device in which the fuel body and the gripping mechanism part are not fixed, the vibration of the fuel gripping device is attenuated, and the vibration of the fuel body is not constrained, so there is no need to wait until it decays naturally. Nakatsuta. In addition, the current control method of the fuel exchanger is to move horizontally with the fuel body loading angle of ± 45 ° or ± 135 ° being maintained, so that the fuel body will not move when the fuel body handle and the fuel grip device grapple are combined. In the direction of swaying, it was necessary to wait a considerable time for the swaying of the fuel body to decay before loading the fuel body into the fuel storage rack or the core.

[Problems to be solved by the invention]

The time for one step (movement to the target fuel body → grasping of the fuel body → movement to the target position → insertion of the fuel body) of the fuel replacement work in the automatic control of the prior art is about 11 minutes on average. Of these, the run-out waiting time requires one minute, and shortening the run-out waiting time is very effective in shortening the refueling time.

The above-mentioned conventional technique attenuates only the shake of the fuel gripping device, and no consideration is given to the attenuation of the shake of the fuel body, and there is a problem in reducing the shake waiting time.

Further, when a plurality of fuel bodies are simultaneously transferred, if the fuel bodies are aligned on the same axis as the traveling direction, there is a risk of collision between the fuel bodies during an emergency stop or the like.

A first object of the present invention is to reduce the run-out waiting time between the fuel body and the fuel gripping device, and a second object of the present invention is to provide a fuel for simultaneously transferring a plurality of fuel bodies. It is to prevent a collision due to body shake.

[Means for solving problems]

The above object is achieved by controlling the orientation of the handle of the fuel body so that it is always parallel to the horizontal movement direction by the rotation of the fuel body gripping mechanism. Here, to make the direction of the handle parallel to the moving direction in the horizontal direction means to make the attaching direction of the handle to the fuel body parallel to the moving direction of the horizontal component.

Further, in an apparatus that handles a plurality of fuel bodies at the same time, when the plurality of fuel bodies are transferred along the same axis as the traveling direction, the orientations of the handles of the plurality of fuel bodies are controlled to be parallel to the traveling direction. For example, when passing through the gate between the core and the spent fuel pool, control is performed so as to be parallel to the axial direction connecting the core and the spent fuel pool.

[Action]

Before the refueling machine moves horizontally, calculate the moving direction,
The fuel body gripping mechanism is rotated so that the fuel body handle is parallel to it. When the moving direction is changed, the fuel body gripping mechanism is rotated so that the fuel body handle is always parallel to the moving direction. If the direction of the handle is set to be parallel to the moving direction, the vibration of the fuel body is restrained by the engagement state between the handle and the hook portion of the fuel body gripping mechanism portion. That is, as shown in FIG. 9 (B),
When the orientation of the handle 61 of the fuel body 36 intersects the moving direction, the fuel body 36 swings in the moving direction around the contact portion between the hook 60 and the handle 61. However, if the handle 61 is oriented parallel to the moving direction as shown in FIG. 9 (A), the contact length between the hook 60 and the handle 61 in the moving direction is longer than that in the case where the hook 60 and the handle 61 intersect. A shake in the moving direction around the contact portion between the hook 60 and the handle 61 can be suppressed. Further, the body 62 further restrains the shake. As a result, the fuel body and the fuel grip device
Since it swings like a single rod, it becomes possible to damp the shake early without changing the configuration of the fuel gripping device steady rest device that has already been devised.

When a plurality of fuel bodies are transferred simultaneously, for example, the fuel body handle is controlled to be parallel to the space between the core and the spent fuel pool before horizontal movement. This reduces the vibration between the plurality of fuel bodies and prevents the fuel bodies from colliding with each other.

Example of Invention

 An embodiment of the present invention will be shown below.

FIG. 7 (A) shows a cross-sectional view of the boiling water reactor core.
In this figure, 36 is a fuel assembly, 40 is a control rod, and 41 is LP.
Indicates RM (local output detector).

Further, as shown in FIG. 7B, 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 1.1 million KW class power generation reactors, and it is necessary to replace the fuel assemblies for 1/4 to 1/3 cores at every 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 exchanger will be described with reference to FIG. The refueling machine includes a traveling carriage 1, a traverse carriage 2, a clasp 4, a telescopic tube 3 and a hoist 5. The traveling vehicle 1 is moved by a drive motor 8 on a pair of knots 6 installed on both sides of a core pool 32 and a fuel storage pool 30, which will be 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 driving force of the grapple rotation driving device 55 in order to adjust the loading angle of the fuel. Further, this glass 4 is attached to the lower ends of several expansion tubes 3. Hereinafter, the moving direction of the traveling carriage 1 is referred to as X, the moving direction of the traverse carriage 2 is referred to as Y, the lifting and lowering of the graph 4 is referred to as Z, and the rotation is referred to as θ.

Next, the detailed configuration of the fuel gripping device will be described with reference to FIG.

The expandable tube 3 can be expanded and contracted in the vertical direction by the hoist 5 and the sheave 10 that changes the direction of the wire rope. Since the expansion tube 1 is mounted on a carriage (not shown) that moves in the horizontal direction, a universal mechanism 11 is provided to avoid stress concentration on the upper part of the expansion tube 3.

A steady rest 12 is provided to damp the shake of the expansion tube 3 caused by the movement of the carriage. A structure is provided in the lower part of the expansion tube for grasping the fuel body 36. The fuel body 36 hung on the grapple 4 can freely swing in the left-right direction with respect to the paper surface, but hardly swings in the direction perpendicular to the paper surface. It is said. Therefore, when the refueling machine moves in the horizontal direction with respect to the plane of the drawing, a secondary runout occurs between the expansion tube 3 and the fuel body 36 (see FIG. 5). FIG. 6 is a graph showing how the expandable tube 3 swings when the fuel body 4 is suspended. The vertical axis is the deflection displacement of the expansion tube, and the horizontal axis is time. As can be seen from the figure, the deflection of the expansion and contraction tube 3 does not form a clean sine wave like one pendulum, and it is understood that the fuel body 36 acts as a double pendulum. Further, even after the refueling machine is stopped, the shake of the expansion tube 3 is attenuated by the steady rest, but the fuel body 36 naturally waits for the attenuation.

Therefore, the conventional control method is to lift the fuel body 36 in the fuel storage pool or the reactor, and then use the same angle (± 45
(°, ± 135 °)
36 was prone to wobbling, and the fuel gripping device was rotated at the loading position according to the loading angle, and then waited until the wobbling of the fuel body was attenuated, and then the fuel was loaded into the fuel storage pool or the core.

That is, there was a problem that the fuel body 36 was horizontally moved at an angle at which it could easily swing.

Next, a method for controlling the fuel gripping device, which is a preferred embodiment of the present invention, will be described with reference to FIGS. The mechanical structure of the fuel exchanger is as shown in FIG. 8 above. Therefore, before the fuel exchanger horizontally moves, the fuel gripping device is rotated so that the horizontal movement direction and the handle of the fuel body 36 are parallel to each other. That is, the control is performed so that the vertical direction and the horizontal movement direction are parallel to the paper surface of FIG. This control is carried out by a command when the grapple rotation driving device 55 for changing the angle of the grapple 4 and the grapple rotation angle detector 54 for detecting the grapple rotating angle, the current grapple angle (direction) and the moving direction of the fuel body are deviated. The X and Y speed command signals 50 are taken in, and the grapple angle comparison calculator 51 and the grapple angle comparison calculator which perform comparison calculation so that the moving direction of the fuel body and the handle 61 of the fuel body are always parallel.
In response to the signal from the 51, the grapple rotation angle command device 52 issues a grapple rotation angle command signal 53 to the grapple drive device 55 so that the handle 61 is always parallel to the transfer direction. If the horizontal movement is performed in this state, the shake between the glass 4 and the fuel body 36 is unlikely to occur, and it can be considered that the glass 4 and the fuel body 36 are almost fixed. Therefore, expansion tube 3 and fuel body
36 can be thought of as one rod swinging, and with the fuel gripper steady rest 12 already invented,
By pressing the upper portion of the expansion tube 3 with a damper, the vibrations of the expansion tube 3 and the fuel body 36 can be attenuated at the same time. As a result, it is possible to shorten the time to wait for the natural decay of the fuel body 36 that is currently being performed, and to shorten the swing waiting time.

Next, an example of a fuel changer (see FIG. 4) capable of simultaneously handling a plurality of fuel bodies will be described with reference to FIG. Before the refueling machine moves horizontally, the fuel gripping device is rotated so that the X-axis direction is parallel to the fuel body handle. That is, control is performed so that the vertical direction and the X-axis direction are parallel to the paper surface of FIG. When the horizontal movement is performed in this state, the fuel body 4 suspended by the plurality of fuel gripping devices 14, 14 'easily shakes in the Y-axis direction, and hardly shakes in the X-axis direction. That is, the plurality of fuel bodies 36 swing so as to pass each other, and this control is one of the measures for preventing the fuel bodies 36 from colliding with each other.

An embodiment of the present invention will be described below with reference to FIG.

First, the case of handling the fuel bodies 36 one by one will be explained.
Grab the fuel body 36 and move up. Next, the fuel gripping device 14 is rotated so that the handle of the fuel body 36 is controlled to be parallel to the direction from. The fuel gripping device 14 is rotated so that the handle from the fuel assembly 36 is parallel to the direction from when the fuel gripping device 14 passes. The same control is applied when passing through. Although the shake waiting is performed at the position, the shake of the fuel body 36 is suppressed to a sufficiently small amount by the rotation control of the fuel gripping device 14 until now, and the shake waiting time can be shortened. In the next position, the fuel gripper 14 is rotated at a predetermined angle for core loading and the fuel body 36 is inserted into the position.

When the fuel is removed from the spent fuel rack and can be moved in the horizontal direction at the stage of rising from to, it is necessary to add the operation of → to the operation of → to transfer the fuel. This has the effect of shortening the transfer time.

Next, a case where a plurality of fuel bodies are simultaneously transferred will be described.

Fuel body 36 taken out in Up to. At this position, rotate the fuel grip device 14 so that the handle of the fuel assembly 36 is parallel to the X axis. Move horizontally to. Here, the fuel body 36 for the group 4
Since the deflection of the fuel is parallel to the Y axis, it is one of the means for preventing the fuel bodies 36 from colliding with each other. next Move horizontally to Move horizontally to. Wait for runout at this position, rotate the fuel gripping device to the specified angle for core loading, Insert the fuel assembly 36 at the position.

In addition, Up to and I did not move it in parallel with the running direction,
Similar to the above-described embodiment, it may be moved in parallel to the moving direction, in which case the shake waiting time can be shortened.

Next, the effect of handling the fuel bodies 36 one by one will be described.

Currently, 1,100MWe class plant is moving about 1,200 fuels per regular inspection, and running f is about 1,700 times. Currently 1
The run-out waiting time of the cycle is set to 60 seconds, which is set according to the longest run-out decay time in the state where the fuel is suspended, and the present invention is adopted to suspend the fuel. If it can be set to the decay time in the absence state, the shake waiting time can be set to about 15 seconds. This leads to a reduction of about one day in one regular inspection.

〔The invention's effect〕

According to the first aspect of the invention, since the vibration of the fuel body itself generated by the transfer can be attenuated in a short time, the effect of shortening the regular inspection work period accompanying the movement of the fuel body can be obtained. .

According to the third aspect of the invention, the vibration of the fuel body itself generated by the transfer can be attenuated in a short time, and a plurality of fuel bodies can be transferred at the same time while preventing the fuel bodies from colliding with each other. Therefore, it is possible to obtain the effect of further shortening the regular inspection work period involving the movement of the fuel body.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a fuel gripping device of a control portion of the present invention,
FIG. 2 is a control flow diagram of the present invention, FIG. 3 is a diagram illustrating a transfer procedure according to the present invention, FIG. 4 is a diagram illustrating a modified example of the present invention, and FIG. 5 is a supplementary explanatory diagram. , FIG. 6 shows the fifth
FIG. 7 (A) is a plan view of the core, FIG. 7 (B) is an enlarged view of part B of FIG. 7 (A), and FIG. 8 is a graph of the fuel converter. FIG. 9 (A) is an enlarged view of the engaging portion between the handle and the shoe when the handle of the fuel body is parallel to the moving direction, and FIG. 9 (B) is an enlarged view when the handle intersects. Is. 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 …… Truck carriage drive motor, 10 …… Sheeve, 11 …… Universal mechanism, 12 …… Stabilizer, 13 …… Grip mechanism section, 14…
… Fuel gripping device, 36 …… Fuel body, 40… Control rod, 41…
… LPRM.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noriaki Hattori 3-1-1 Sachimachi, Hitachi, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Tetsuro Wake 3-chome, Hitachi, Hitachi, Ibaraki 1-1 Hitachi Ltd., Hitachi Works, Hitachi Plant (72) Inventor Akira Koizumi 3-1-1, Saiwaicho, Hitachi City, Ibaraki Hitachi Ltd., Hitachi Works, Hitachi Plant (56) Reference JP 54-138989 (JP, A)

Claims (4)

[Claims] 1. A traveling carriage that travels on a core of a nuclear power plant and a fuel storage pool; a traverse carriage that traverses the traveling carriage; and a suspension carriage that is vertically movable and hung on a horizontal plane. A hook portion that engages with a handle portion on an upper portion of the fuel body to grab the fuel body, and a contact interval between the hook portion and the handle portion along the direction of the handle portion is in the engaged state. A fuel exchanger including a fuel body gripping device having a shape wider than a contact interval with the handle portion along another direction orthogonal to the direction is used, and the fuel body is disposed between the core and the fuel storage pool. A method of engaging and transporting a hook portion, the method comprising: a horizontal movement direction of the fuel body when the horizontal movement of the fuel body is performed by the traveling carriage or the transverse carriage. A method of controlling a fuel exchanger, wherein the direction of the handle portion of the fuel body is controlled so as to be parallel to each other by rotating the hook portion engaged with the handle portion to transfer the fuel body. . 2. The fuel cell assembly according to claim 1, wherein the fuel body is moved in the horizontal direction along with the movement in the vertical direction when the fuel body is moved up in the vertical direction and reaches a position where the fuel body can be moved in the horizontal direction. A method for controlling a refueling machine, which is characterized by performing. 3. A traveling carriage that travels on a core and a fuel storage pool of a nuclear power plant, a plurality of traversing carriages that traverse the traveling carriage, and a plurality of the traversing carriages that are vertically movable and rotatable in a horizontal plane. Is hung at
Hook portions for engaging with the handle portion on the upper portion of the fuel body to grasp the fuel body, and the contact distance between the hook portion and the handle portion along the direction of the handle portion in the engaged state. Using a fuel exchanger equipped with a plurality of fuel body gripping devices having a shape wider than the contact interval with the handle portion along another direction orthogonal to the direction, and using a plurality of the fuel exchangers between the core and the fuel storage pool. A method of transferring a fuel body by engaging with each of the hook portions, comprising: when the plurality of fuel gripping devices are made to travel on the same horizontal line by the traveling carriage or the plurality of traverse carriages, The directions of the handle portions of the plurality of fuel bodies are controlled by rotating the hook portions engaged with the handle portions so as to be substantially parallel to the same horizontal movement direction of the fuel body. The method of refueling machine, characterized in that transferring the fuel of a few. 4. The control of a fuel exchanger according to claim 3, wherein the traveling direction in which the plurality of fuel gripping devices are on the same line is a line connecting the core and the fuel storage pool. Method.