JPH0113557B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for handling nuclear fuel (assembly) of a nuclear reactor in a pressurized water nuclear power plant or the like.

The life of the nuclear fuel used in pressurized water nuclear power plants is usually three years, and the reactor is opened once a year to replace fuel for one-third of the core and refuel the remaining two-thirds. Periodic inspections of the fuel used will be carried out. Therefore, all the fuel is removed from the reactor and stored in a fuel storage pool (also called a spent fuel pool).
After the various fuel inserts are replaced and inspected within the pool, some of them are loaded into the reactor again.

The nuclear fuel handling device of the present invention is attached to a fuel storage pool in order to transfer fuel in the pool and replace its inserts.

An outline of the fuel storage pool and nuclear fuel handling equipment described above is shown in Figs. 1 and 2, in which a indicates a group of racks arranged in the pool, b indicates a gate between each pool room, and c indicates a nuclear fuel storage pool. In this conventional plant, a self-propelled crane e is installed on the traveling rails 1, 1 laid on both sides of the fuel storage pool, and a manual crane e is installed at the upper end of the crane e in the traveling direction and in the direction perpendicular to the traveling direction. Attach an electric hoist f that can be moved horizontally,
A special handling tool g is installed vertically on the electric hoist f via a wire rope, so that the suspended load can be moved in the three-dimensional directions of X-Y-Z, and the fuel c can be transferred and its inserted objects can be replaced. It's becoming like that.

However, in the above-mentioned nuclear fuel handling equipment, movement in the X-Y-Z directions is performed manually, and depending on the object to be handled (about 4 hours, including nuclear fuel and its interpolated materials). It is necessary to replace the dedicated handling tool g each time, and in recent years,
In the regular inspection work of nuclear power plants,
There is a strong desire to shorten the required time and reduce radiation exposure for workers, and it has become essential to automate nuclear fuel handling equipment and consolidate dedicated handling tools. However, the structure is difficult to automate due to the fact that it shakes when running and has problems with positioning accuracy when stopped.

The present invention has been developed in view of the above-mentioned circumstances regarding conventional nuclear fuel handling equipment, and is for handling nuclear fuel assemblies and inserts that are inserted and removed from above into the nuclear fuel assemblies. A telescopic mast is vertically mounted on a transverse bogie mounted on a longitudinal bogie, and a gripping portion for a nuclear fuel assembly is attached to a peripheral edge of a guide tube that is vertically movably mounted in the inner mast of the telescopic mast. The present invention is characterized in that an insert insertion/removal member is provided in the guide tube and is movably arranged in the guide tube to grasp the insert in the nuclear fuel assembly and move up and down to insert and remove the insert into the nuclear fuel assembly. The purpose of this is to have a gripping part for a nuclear fuel assembly and a member for inserting and removing the insert therein, so that they can be automatically controlled so that they can be operated stably with minimal shaking. The purpose of this invention is to provide nuclear fuel handling equipment that can handle nuclear fuel.

The present invention has the above-mentioned configuration, in which a telescope mast is vertically installed on a transverse carriage equipped with a longitudinal carriage, and a guide tube is mounted in the inner mast of the telescope mast so as to be movable up and down. A gripping portion for the nuclear fuel assembly is provided on the peripheral edge of the tip, and an insert insertion/removal member is provided in the guide tube that grips the insert inside the nuclear fuel assembly and moves up and down to insert and remove it into the nuclear fuel assembly. Since the nuclear fuel assembly is movably arranged, the gripping part of the nuclear fuel assembly supported from the transverse carriage via the telescopic mast and the guide tube attached thereto, and further disposed and supported in the guide tube. The handling parts of the insert can be operated stably with almost no shaking.
Nuclear fuel assemblies and inserts can be grasped and handled accurately and easily, and both operations can be done equally quickly.
Various mechanisms can be automatically controlled and can be controlled by a remote control mechanism. Further, since the gripping portion and the insert insertion/removal member can be moved up and down greatly by the telescope mast and the guide tube without shaking, there is an advantage that the device can be easily and quickly moved vertically and horizontally.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Figs. 1 and 2 show an overview of an example of use in an embodiment of the present invention, Figs. 3 and 4 show a mechanism of an embodiment of the present invention, and Fig. 5 shows how the embodiment is used. In Figures 1 and 2,
Within the fuel storage pool, a group of rectangular fuel racks a are arranged in orthogonal coordinates, each of which can accommodate one nuclear fuel assembly c (hereinafter simply referred to as fuel c).

As shown in the figure, the pool is divided by a gate b into a pool room A in which a group of fuel racks A are arranged, a canal part B, and an inspection pit part C;
During normal plant operation, only pool room A is filled with water and the other parts B and C are dry, but during the inspection, all gates B are removed and communicated, and the entire pool is filled with water. .

Vertical travel rails 1, 1 for nuclear fuel handling equipment are laid on both floors of the pool.

FIG. 3A shows the structure of the nuclear fuel handling system of the present invention during normal operation and FIG. 3B shows the structure of the nuclear fuel handling system according to the embodiment of the present invention during mast lifting. ), it is possible to move vertically on the pool, and the transverse carriage 3 mounted on the longitudinal carriage 2 can move transversely in a direction perpendicular to the running direction of the longitudinal carriage 2 (both are driven by electric motors). Also,
A fixed mast 4 is mounted on the traversing truck 3, and a telescopic mast formed by a combination of an outer mast 5 and an inner mast 6, which will be described later, is vertically installed on the fixed mast 4.

FIG. 4 shows the structure of the embodiment of the present invention,
The outer mast 5 and the inner mast 6 have a cylindrical telescope shape as shown in the figure, and the inner mast 6 can only freely expand and contract in the vertical direction relative to the outer mast 5. It is attached to a fixed mast 4 on 3 so that it can only rotate freely in a horizontal plane. Its rotation is for fine adjustment and is normally locked mechanically with a stopper, etc. not shown.
A stopper 7 restricts the lowering of the inner mast 6 due to its own weight. In addition, the inner mast 6
A plurality of guide rollers 8 are fixed to the inner mast 6, and these support a cylindrical guide tube 9 so that it can expand and contract in the vertical direction while being rotationally restrained relative to the inner mast 6.

At the lower end of the guide tube 9, a fuel gripping portion and a fuel insert guide member having a structure described later are attached.

The fuel gripping portion includes a plurality of guide pins 10 for positioning the fuel c, a plurality of gripping claws 11, and the same claws 1.
The gripping claw 11 is housed in the frame 13, and the gripping claw 11 is housed in the frame 13. When fluid pressure is applied to the side, the gripping pawl 11 comes out under the frame 13 by the action of a cam as shown in FIG. 5B, which will be described later, and can grasp the fuel c.

The frame body 13 is provided with an insert guide portion consisting of a comb-shaped insert guide plate 14 and a cylinder 15 for actuating the guide plate 14, and the reciprocating movement of the cylinder 15 guides the insert. The plate 14 can be rotated inward by about 90 degrees. (FIG. 5C, which will be described later, shows a state in which the insert is being rotated and guided.) In addition, the guide tube 9 includes a tube for grasping the insert d attached to the fuel c. A gripping tube 16 is built in so that it can move up and down, and a guide tube 9
Guide rails 17 and guide rollers 18 are installed so as to be able to expand and contract in the vertical direction while rotationally restrained. The guide rail 17 is inside the guide tube 9, and the guide roller 18 is inside the grip tube 1.
6 are each fixed on the outside.

Therefore, the guide tube 9 is
The gripping tubes 16 each have a structure that allows them to expand and contract in the vertical direction while being restrained in their rotational direction.

Furthermore, a rod 19 with a tapered lower end is built into the gripping tube 16, and serves as an insert insertion/removal member that allows the rod 19 to be moved up and down with respect to the gripping tube 16 by means of a cylinder 20 installed at the top. ing.

Next, regarding the suspension means for the guide tube 9 and the gripping tube 16, the gripping tube 16 is
It can be hoisted up and down by a hoisting machine 21 (see FIG. 3A) via two wire ropes 23 and a sheave 22. On the other hand, the guide tube 9 has two stages of stoppers 24 or 2 attached to the gripping tube 16.
The stopper cylinder 26, which is suspended by the wire rope 23 through the guide tube 9, moves the stopper 24 position (state shown in FIG. 4) and the stopper 25 position (state shown in FIG. 5 C) by the action of the stopper cylinder 26 attached to the guide tube 9. It can be suspended in two stages.

The illustrated embodiment has the above-mentioned structure, and the operation will be explained next.The nuclear fuel handling device of this embodiment has the structure shown in FIGS. Rearrangement of fuel c between groups and replacement of various inserts d inserted into fuel c, such as control clusters, single plugs (those that block unused control rod guide tubes), etc. This will be explained with reference to FIGS. 5A to 5C.

(i) Concerning the transfer of fuel, the initial state of the telescopic mast when taking out fuel c and transferring it to another rack is the state shown in Figure 4, in which it is moved transversely with the longitudinal truck 2 onto the predetermined fuel rack a. After positioning with the trolley 3, when the guide tube 9 is lowered by hoisting the hoist 21, the guide pin 10 is inserted into a hole (not shown) provided in the fuel top, and the fuel c and the guide tube 9 are lowered. be positioned. With the guide tube 9 seated on the fuel, the hoisting machine 21 is stopped to create the state shown in FIG. 5A.

Next, fluid pressure is applied to the porthole side of the pawl actuating cylinder 12 to grasp the fuel c with the grip pawl 11, and then the hoist 21 pulls the fuel rack a from the upper end of the fuel rack a as shown in FIG. 5B. Whirl up the fuel a little to the top.

After positioning it on another fuel rack into which fuel is inserted by moving by the vertical truck 2 and the transverse truck 3, lower the rack until the fuel is seated on the bottom of the rack in the same way as above, and apply fluid pressure from the portoy side of the cylinder 12 for actuating the claw. flows in, and the gripping claw 11 is separated from the fuel c and moved slightly upward.

(ii) Regarding the replacement of the insert, this is done mainly by the insert insertion/removal member consisting of the grip tube 16, rod 19, etc., and only the insert d inserted into the fuel c is replaced. The pattern is to remove the fuel and insert it into another fuel, and the process is the same as in (i) above until the guide tube 9 is lowered and is seated on the fuel (FIG. 5A), and then the hoisting machine 21 is lowered. Only the gripping tube 16 is lowered, and its lower end is fitted into the hole at the top of the insert d. In this state, the hoisting machine 21 is stopped, and the rod 19 is pushed down by the cylinder 20 so that the lower end of the gripping tube 16 grasps the insert d.

Next, the stopper is removed using the stopper cylinder 26, the hoisting machine 21 is hoisted, and the insert d is removed from the fuel c.
At the same time, the insert guide plate 14 is rotated inward by approximately 90 degrees by the operation of the guide plate actuating cylinder 15 to guide the rod portion of the insert. Note that the insert is lifted up while being guided by the guide plate 14. Before the stopper 25 passes through the cylinder 26 installed at the upper end of the guide tube 9, when the stopper 25 is engaged and stopped by the cylinder, the gripping tube 1 is stopped.
6. The guide tube 9 begins to rise via the stopper 25.

After the guide tube 9 is pulled up slightly above the upper end of the fuel rack a, as shown in FIG. 5C, it is moved horizontally to another level of fuel.

Thereafter, the pattern for inserting the insert d into another fuel can be generally performed by the reverse procedure of the above-mentioned extraction (details are omitted).

(iii) Regarding lifting of the telescopic mast, the fuel storage pool should be filled with water to shield radioactivity when fuel is stored, and the canal section shown in Figure 1 should be inspected during plant operation. Since water has been drained from pit portion C, gate b is closed.

However, since the mast is in the telescope shape as in the embodiment, when the gate is closed, it is easy to raise and retract the inner mast 6 to allow passage through the gate b section, as shown in FIG. 3B. As shown, the inner mast 6 can be housed in the outer mast 5 and the guide tube 9 can be housed in the inner mast 6, making it extremely easy to move vertically and horizontally by the longitudinal carriage 2 and the transverse carriage 3. Moreover, it can be done quickly and maintainability can be improved.

The mast is pulled up using the hoisting machine 21 via the guide tube 9 to the position shown in FIG. 3B.

Note that the positioning of both carts and the order of operation of each mechanism can be performed by an appropriate control device having a memory circuit (not shown), and the system can be configured as a remote automatic driving mechanism.

At nuclear power plants, periodic inspections are shortened,
There is an urgent need to reduce the radiation exposure of workers, and the effects of accelerating the operation of nuclear fuel handling equipment accurately and remotely as well as automating it remotely will be extremely effective.

However, conventional equipment requires manual operation, requires long hours of work by many workers, and requires the replacement of several types of special tools depending on the object being handled. However, according to the above-mentioned embodiment, the robot is supported from the traversing truck via a telescopic mast and a guide tube attached to it. The fuel gripping part, the insert insertion/removal member disposed and supported in the guide tube, etc. all operate accurately with almost no shaking and stable vertical movements.
The fuel and inserts can be grasped and handled accurately, easily, and quickly, and various mechanisms can be automatically controlled and remotely controlled, increasing work efficiency and reducing the number of workers and therefore the amount of radiation exposure. can.

In the above embodiment, the inner and outer masts are used to enable vertical expansion and contraction, but it is also possible to substitute the outer mast with the mechanism itself on the device side.
In addition, although the mast hoisting machine is shared with the hoisting machine for the fuel handling mechanism, it is also possible to operate only the inner mast with a separate hoisting machine, which would improve load monitoring, etc. It is advantageous.

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that various design modifications can be made without departing from the spirit of the present invention. .

[Brief explanation of drawings]

Figure 1 is a plan view of a conventional general fuel storage pool.
FIG. 2 is a schematic diagram showing the relationship between the vertical section of the pool shown in FIG. 1 and the nuclear fuel handling equipment attached thereto; FIG. B is a view of one usage mode of FIG. 3A, FIG. 4 is an enlarged sectional view of FIG. 3A, and FIGS. 5A, B, and C are explanatory diagrams of each usage mode of FIG. 4. 1: Running rail, 2: Vertical bogie, 3: Traverse bogie, 4: Fixed mast, 5: Outer mast, 6: Inner mast, 9: Guide tube, 10, 11, 12, 1
3: fuel gripping part, 14: insert guide plate, 16,
19: Insert insertion/removal member.

Claims (1)

[Claims] 1. In those that handle nuclear fuel assemblies and inserts that are inserted into and removed from the nuclear fuel assemblies from above, a telescopic mast is installed vertically on a transverse bogie mounted on a longitudinal bogie, and the telescopic mast A gripping portion for the nuclear fuel assembly is provided at the tip peripheral edge of a guide tube that is installed in the mast so as to be able to move up and down. A nuclear fuel handling device characterized in that an insert insertion/removal member that is inserted into and removed from an assembly is arranged to be movable up and down.