JPH0511279B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a nuclear fuel handling device in a nuclear power plant, and particularly to a nuclear fuel handling device suitable for use as a refueling machine in a nuclear reactor.

[Conventional technology]

Transfer of conventional BWR fuel assemblies is described in Japanese Patent Application Laid-open No. 1983.
As shown in Japanese Patent No. 34392, this is done using a single fuel exchanger between the reactor core and the fuel storage pool.

On the other hand, in order to shorten the fuel exchange time,
As described in Japanese Patent No. 54-47988, a fuel exchanger has been proposed that has two hooks and grips two fuel assemblies at a time.

[Problem to be solved by the invention]

In the prior art described in Japanese Patent Application Laid-Open No. 58-34392,
The transfer of fuel assemblies is carried out by a single fuel exchange machine, so in order to shorten the transfer time, it is necessary to increase the driving speed of the fuel exchange machine, but this is a device that handles fuel assemblies. Above all, there is a limit to speed up.

In the conventional technology described in Japanese Patent Application Laid-Open No. 54-47988,
Depending on the arrangement of the fuel assemblies in the reactor core, a refueling machine having two hooks may not be able to grip two fuel assemblies at the same time, but may grip only one fuel assembly. In particular, it is difficult to take out two fuel assemblies arranged at the outermost periphery of the core. This is because a fuel exchanger with two hooks can easily grip two fuel assemblies arranged diagonally, but the remaining outermost fuel assemblies arranged in a straight line can be gripped two by two. It is difficult to take it out. As a result, only one of the two hooks grips one fuel assembly, making it impossible to maintain balance and causing problems in the running of the fuel exchange machine.

An object of the present invention is to provide a nuclear fuel handling device that can easily change the number of fuel assemblies that can be gripped at one time and that can transfer fuel smoothly and in a short time regardless of the number of fuel assemblies that can be gripped. Our goal is to provide the following.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a nuclear fuel handling system in a nuclear reactor power plant, including a traveling truck, and a vehicle placed on the traveling truck and arranged in a direction perpendicular to the traveling direction of the traveling truck. two independently drivable transverse bogies running on rails, and two independently drivable fuel gripping devices each having a telescoping pipe and a fuel gripping device, each of which is provided on each of the two transverse bogies. One of the two transverse bogies has a protruding portion parallel to the rail on one side when viewed from above, and the other transverse bogie is adjacent to the protruding portion of the one transverse bogie. It has a part that can enter into the space, and the fuel gripping device provided on one of the transverse carts is installed in the protruding part, and the fuel gripping device provided in the other transverse cart is installed in the part that can enter into the space. Provided is a nuclear fuel handling device characterized by the following.

[Effect]

By arranging two traversing carts that can be driven independently in the form of running carts, it is possible to handle two fuel assemblies at a time. Further, the fuel gripping device of one of the traversing trucks is installed on the protruding part of the traversing truck, and the fuel grabbing device of the traversing truck is arranged in a part of the other traversing truck that can enter the space adjacent to the projecting part. Therefore, when the two traversing carts are brought to the center, the two fuel gripping devices are arranged almost in line with the direction of movement of the traversing carts, allowing the nuclear fuel handling device to pass smoothly through the gates on the movement route. It becomes possible. These make it possible to transfer two fuel assemblies, for example, in one round trip from the reactor core to the spent fuel pool, thereby significantly shortening the fuel exchange work time.

By placing two traversing carts on the same rail, the conventional traveling cart can be used almost as is, and it can be applied to existing nuclear reactor equipment at low cost.

Furthermore, by placing two transverse carts on the same rail, the increase in the overall height of the nuclear fuel handling equipment can be suppressed, reducing the cost of the nuclear fuel handling equipment and improving the efficiency of in-core service work. Furthermore, since the fuel gripping device can be designed with the same specifications, high reliability can be ensured.

〔Example〕

Figure 4A shows a cross section of the core of a boiling water reactor. In this figure, 1 is a fuel assembly, 2 is a control rod, and 3 is an LPRM (local output detector). Also,
As shown in Figure 4B, 4 surrounding one control rod 2
The fuel assembly 1 of the body constitutes a cell. The handles 1A of these four fuel assemblies 1 face the control rods 2.

When a nuclear reactor is operated, the reactivity of the reactor core decreases, so spent fuel assemblies must be periodically replaced with new fuel assemblies. The operating engine of a nuclear reactor from the previous fuel exchange to the next fuel exchange is called a cycle, and the fuel assembly is replaced with a new fuel assembly at the end of each cycle. The number of fuel assemblies in the core is approximately 800 in a 1.1 million class power reactor, and 1/4 to 1/3 of the fuel assemblies 1 must be replaced at every inspection.

FIG. 5 shows the loading pattern of the fuel assemblies 1 in the core of a boiling water nuclear reactor, that is, the state of the arrangement of the fuel assemblies 1. In the figure, numbers 4 to 6 for each fuel assembly 1 indicate the number of core stay cycles, and fuel assemblies 1 with the same number should be replaced at the same time. In Figure 5, the number of cycles is 4,
The fuel assemblies 1 of 5 and 6 are designated by symbols 4, 5, and 6, respectively.
It is indicated in 6. Here, the fuel assemblies 1 to be replaced at the same time, for example, the fuel assemblies 1 with a cycle number of 6 marked with diagonal lines, are always arranged adjacent to each other in a row in the diagonal direction.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The use of a nuclear fuel handling device as a preferred embodiment of the present invention as a fuel exchanger will be explained with reference to FIGS. 1 to 3.

The nuclear fuel handling device 10 of this embodiment consists of one running trolley 16, two running in the same direction on a transverse rail 19 laid at the same level above the running trolley 16.
Traversing carts 17A and 17B, and Traversing cart 1
7A and 17B, respectively.

One of the two transverse carriages 17A, 17B, as seen from above, has a protruding portion 1 parallel to the rail 19 on one side thereof.
7a, and the other traversing truck 17B has a rectangular shape having a portion 17b that can enter into a space adjacent to the protruding portion 17a of the traversing truck 17A. 30A is installed on the protruding portion 17a, and a fuel gripping device 30B provided on the traversing truck 17B is installed on the accessible portion 17b.

The fuel gripping device 30A includes a telescopic tube 11A formed by combining a plurality of cylinders with different diameters in the axial direction, and a fuel gripping tool (for example, a hook) 12A attached to the lower end of the telescopic tube 11A. The fuel gripping device 30B includes a telescopic tube 11B and a telescopic tube 11B formed by combining a plurality of cylinders with different diameters in the axial direction.
The fuel gripper 12B is attached to the lower end of the fuel gripper 12B. A drive device (not shown) that expands and contracts the plurality of telescopic tubes 11A and 11B in the axial direction is attached to each of the traversing carts 17A and 17B.
The drives for the fuel grabbers 12A and 12B are also installed on the traversing trucks 17A and 17B. The transverse carts 17A and 17B to which the fuel gripping devices 30A and 30B are attached can each travel independently, and the fuel gripping devices 30A and 30B can each be driven independently. Since the traversing carts 17A and 17B move independently on the same rail 19 of the traveling cart 16, a proximity sensor (not shown) is provided to prevent collisions between the traversing carts so that the distance between each traversing cart is a predetermined distance. Each traversing truck is provided with a mechanism that stops the movement of the traversing truck when the distance is within the range. Also,
By monitoring the output signals of the position detection devices (not shown) of the traversing carts 17A and 17B, collisions between the traversing carts 17A and 17B can be prevented.

The fuel exchange operation in this embodiment will be explained below. The steps up to transferring the fuel assembly of the reactor core 8 in the reactor pressure vessel 31 of a boiling water reactor to the fuel rack 14 in the spent fuel storage pool 9 will be explained. At the time of fuel exchange, the upper lid of the reactor pressure vessel 31 is removed, and the cooling water 32 is filled up to the upper part of the reactor pressure vessel 31.

Rail 3 installed on the 5th floor of the reactor building
After positioning in the traveling direction is performed by the traveling carriage 16 that moves on 3, first the traversing carriage 17A is moved and positioning of the carriage in the traversing direction is performed.
Then, the telescopic tube 11A of the fuel gripping device 30A is extended downward to lower the fuel gripping tool 12A. Stop the lowering of the fuel grip 12A, operate the fuel grip 12, and release the handle 1 of the fuel assembly 1.
Grab A. In this state, the telescopic tube 11A is contracted to raise the fuel assembly 1 to a height at which the traversing truck 17A can be moved.

Continuing, the traversing cart 17B and the traversing cart 16
is moved to a position above the fuel assembly 1 to be removed. When the fuel gripper 12B comes above the predetermined fuel assembly 1, the telescopic tube 11B is extended and the fuel gripper 12B is lowered to a position where it can grip the predetermined fuel assembly 1. and fuel grip 1
2B is driven, and the fuel assembly 1 is gripped by the fuel gripper 12B. Fuel gripping tool 12 gripping fuel assembly 1 with telescopic tube 11B contracted
B rises. When the fuel assembly 1 has risen to a predetermined position, the lifting of the fuel gripper 12B is stopped. The transverse bogies 17A and 17B are the fuel assemblies 1
is moved to the center of the carriage 16 as shown in FIG. 2 so that it can pass through the gate 18. gate 18
connects the pool above the reactor core 8 and the spent fuel storage pool 9.

The two lifted fuel assemblies 1 are moved by the fuel gripping devices 30A and 30 by the movement of the traveling trolley 16.
B is transferred to the spent fuel pool 9 through the gate 18. Here, the transverse carts 17A and 1
7B has a roughly L-shape and a rectangular shape, respectively, as described above, the fuel gripping device 30A is disposed on the protruding portion 17a, and the fuel grasping device 30B is disposed on the portion 17b that can enter the space adjacent to the protruding portion 17a. has been done. Therefore, when the transverse carts 17A, 17B are brought to the center as described above, the fuel gripping devices 30A, 30B are moved to the rail 33.
It is positioned substantially in line with the moving direction of the traveling carriage 16 moving above, allowing smooth passage through the gate 18.

After the traveling truck 16 is moved and positioned on a predetermined fuel rack 14 in the spent fuel storage pool 9, the traversing truck 17A moves to the fuel rack 14 on which the fuel assembly 1 gripped by the fuel gripping device 30A is to be loaded. Move it up and position it. After the fuel assembly 1 is stored in the fuel rack 14 by extending the telescopic tube 11A, it is removed from the fuel gripper 12A. Then, the telescopic tube 11A is contracted to raise the fuel gripper 12A to a height at which the nuclear fuel handling device 10 can be moved. Next, the traversing trolley 17B
Then, the fuel assembly 1 held by the fuel gripping device 30B is moved onto the fuel rack 14 to be loaded. After the fuel assembly 1 is stored in a predetermined fuel rack 14 by extending the telescopic tube 11B, it is removed from the fuel gripper 12B. After that, the fuel gripper 12
The nuclear fuel handling equipment raises B to a height where it can be moved. The telescopic tubes 11A and 11B of the fuel gripping devices 30A and 30B move the transverse carts 17A and 17B to a position where they can pass through the gate 18. Here again, when the transverse carriages 17A, 17B are brought to the center, the fuel gripping devices 30A, 30B are positioned substantially aligned in the moving direction of the running carriage 16 moving on the rail 33. The nuclear fuel handling device 10 smoothly passes through the gate 18 and moves to the position of the fuel assembly 1 in the reactor core 8 to be replaced next, completing one step of fuel replacement.

According to this embodiment, two transverse carts 17A, 1
7B is arranged so that it can grip two fuel assemblies at once, and the fuel gripping devices 30A, 30B
Since the structure allows the fuel to pass through the gate smoothly, two fuel assemblies can be smoothly transferred in one round trip from the nuclear fuel handling equipment core to the spent fuel pool, significantly reducing fuel exchange work time. There is an effect that it can be done.

In addition, two transverse carts 17 are placed on the same rail 19.
Since the above-mentioned effect is achieved with the structure in which A and 17B are mounted, the conventional traveling trolley 16 can be used almost as is, and can be applied to existing nuclear reactor equipment at low cost.

Furthermore, according to this embodiment, two traversing carts 17
Since A and 17B are installed at the same level on the traveling truck 16, the increase in the height of the traveling truck 16 is suppressed compared to the case where two transverse trucks are installed one above the other, and therefore the height of the nuclear fuel handling equipment 10 is reduced. The overall height can be kept low and costs can be reduced.

In addition, a traveling trolley 16 carries out service work inside the reactor core 8.
When performing from above, the increase in the height of the traveling carriage 16 is suppressed, thereby avoiding an increase in the distance from the working floor on the traveling carriage 16 to the reactor core, and ensuring good in-core servicing workability.

Furthermore, since the two traversing trucks 17A and 17B are installed at the same level on the traveling truck 16, the telescopic tube 11A in the fuel gripping devices 30A and 30B
and 11B can be made the same. Therefore, the fuel gripping devices 30A and 30B can be designed to the same specifications, and high reliability can be ensured.

In addition, in the nuclear fuel handling device 10, the traveling cart 16, the traversing carts 17A and 17B, and the fuel grippers 12A and 12B are set according to the most rational fuel exchange plan by a computer that controls the nuclear fuel handling device 10. It shall have a function that allows self-determination to operate according to procedures.

In addition, a fuel gripping device 30A in the core 8
In FIG. 2, the fuel gripping device 30A is responsible for the right half, and the fuel gripping device 30B is responsible for the left half, with the line connecting the center of the core 8 and the center of the gate 18 as Sakai. As a result, there is little mutual interference between the traversing carts 17A and 17B, making it possible to take out and load fuel efficiently.

Further, the nuclear fuel handling device 10 can not only transfer two fuel assemblies 1 at the same time, but also transfer one fuel assembly 1. When transferring one fuel assembly 1, it is possible to stably transfer one fuel assembly 1 without losing balance due to the lifted one fuel assembly 1. Therefore, even when one fuel assembly 1 is being held, the nuclear fuel handling device 10 can be transferred quickly and smoothly.

A sixth embodiment of a nuclear fuel handling device according to another embodiment of the present invention
This will be explained using FIG. 7 and FIG.

In FIG. 6, the nuclear fuel handling device 36 is a facility for storing or handling spent fuel assemblies, and includes a traveling trolley 16 that runs on a spent fuel storage pool 9 and two vehicles that run across the traveling truck 16. traversing carts 17A and 17B, and fuel gripping devices 37A and 3 provided on the traversing carts 17A and 17B.
It starts from 7B.

As shown in FIG. 7, the two traversing carts 17A and 17B are roughly L-shaped and rectangular, respectively, similar to the traversing cart shown in FIG.
The fuel gripping device 37A provided in the projecting portion 1
7a, and the fuel gripping device 37B provided on the traversing truck 17B is connected to the accessible portion 17b.
It is installed in

The fuel gripping device 37A includes a telescopic tube 11A and a fuel gripping device 37A.
It has a BWR fuel grip 22. The fuel gripping device 37B has a telescopic pipe 11B and a PWR fuel gripping device 23. This nuclear fuel handling equipment 36 was transferred via canal 24.
The respective fuel assemblies 1 are grabbed from the BWR fuel basket 20 and the PWR fuel basket 21 with their respective fuel grippers, and are transferred to the respective fuel racks 14 through the gates for storage.

According to this embodiment, one unit can handle two types of fuel assemblies at the same time, and as in the first embodiment, it reduces the working time for fuel storage and handling, improves economic efficiency, improves workability, and The effect of improving reliability can be obtained.

〔Effect of the invention〕

According to the present invention, since two fuel assemblies can be replaced at once, the fuel replacement time is significantly shortened.
Moreover, one fuel assembly can be exchanged, and one fuel assembly can be transferred smoothly without losing its balance.

Further, even in the case of fuel handling work other than fuel exchange, the working time can be significantly shortened as well.

Furthermore, since two traversing carts are arranged on the same rail, conventional traveling carts can be used, and the system can be applied to existing nuclear power facilities at low cost.

Furthermore, since the increase in the overall height of the nuclear fuel handling equipment can be suppressed, the cost of the nuclear fuel handling equipment can be reduced, and the distance from the work floor on the traveling trolley to the reactor core can be avoided, making it possible to improve the overall height of the nuclear fuel handling equipment. In-core service workability can be ensured, and since the fuel gripping devices can be designed to the same specifications, high reliability can be ensured.

[Brief explanation of the drawing]

FIG. 1 is a structural diagram of a nuclear fuel handling device according to an embodiment of the present invention, FIG. 2 is a plan view of the nuclear fuel handling device of FIG. 1, and FIG. 3 is a fuel exchange by the nuclear fuel handling device. It is an explanatory diagram showing the operation of
Figure 4A is a plan view of the core of a boiling water reactor, Figure 4B is an enlarged view of part A in Figure 4A, and Figure 5 is the fuel loaded in the core of Figure 4A. FIG. 6 is a structural diagram of a nuclear fuel handling device according to another embodiment of the present invention, and FIG. 7 is a plan view of the nuclear fuel handling device of FIG. 6. . Explanation of symbols, 1... Fuel assembly, 8... Core,
9... Fuel storage pool, 10... Nuclear fuel handling equipment, 11A, 11B... Expansion pipe, 12A, 12B
...Fuel grip, 16...Traveling trolley, 17A,
17B...Transverse truck, 17a...Protruding part, 17
B... Part that can be accessed, 30A, 30B... Fuel gripping device.

Claims (1)

[Scope of Claims] 1. A nuclear fuel handling system in a nuclear reactor power plant, comprising: a traveling bogie; and a rail that is placed on the traveling bogie and is arranged in a direction perpendicular to the traveling direction of the traveling bogie. Two traversing carts that can be driven independently, and each of the two traversing carts are provided with:
two independently drivable fuel gripping devices each having a telescoping tube and a fuel gripping device;
The other transverse bogie has a protruding portion parallel to the rail on one side thereof, and the other transverse bogie has a portion that can enter a space adjacent to the protruding portion of the one transverse bogie,
A nuclear fuel handling device characterized in that a fuel gripping device provided on one of the traversing trucks is installed in the protruding portion, and a fuel gripping device provided in the other traversing truck is installed in the accessible portion.