JPH0677065B2 - Refueling machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a refueling machine for a nuclear power plant, and more particularly,
The present invention relates to a fuel exchanger suitable for simultaneously transferring a plurality of fuel assemblies by a plurality of fuel gripping devices.

[Conventional technology]

The transfer of nuclear fuel in a conventional nuclear power plant or the like has been performed by one fuel exchanger between the fuel storage pools of the core. Therefore, in order to shorten the transfer time, it was necessary to increase the driving speed of the fuel exchanger, but on the other hand, the high degree of safety was required, and the speedup was limited.

Therefore, in order to shorten the transfer time, a nuclear fuel gripping device that grips a plurality of fuel assemblies at the same time and transfers them between the core (hereinafter referred to as the core) and the fuel storage pool (hereinafter referred to as the pool) (Japanese Patent Laid-Open No. 60-166895). No.) was proposed.

[Problems to be solved by the invention]

The nuclear fuel gripping device described above has an advantage that it can transfer a plurality of fuel assemblies at the same time, halves the time required for refueling work, and significantly shortens the periodic inspection period of the nuclear power plant. Is designed for a fuel assembly with a conventional burnup, and the degree of freedom is not necessarily large.In particular, in recent high conversion reactors, the loading of fuel storage racks in the fuel storage pool is difficult due to the criticality problem. The pitch etc. may change, and it is predicted that it will not be able to cope with this sufficiently.

On the other hand, Japanese Patent Application Laid-Open No. 61-65192 discloses that, in an exchange that takes out two fuel assemblies at a time, if one fuel assembly is hung only on one of the two hooks, it will not be balanced, so For the purpose of avoiding the drawback of causing obstacles, a traveling carriage, a plurality of lateral traveling carriages traveling on the traveling carriage in a direction orthogonal to the traveling direction of the traveling carriage, and a fuel gripping device attached to each of the horizontal traveling carriages. And a refueling machine consisting of

In this fuel exchange machine, as is apparent from the embodiment, the fuel exchange machine is operated one at a time in response to the above-mentioned purpose of emphasizing balance.
Only grasping and moving up and down the body fuel assembly, and grasping and moving up and down two fuel assemblies at the same time are not considered.

Further, although the pitch between the fuel catching devices in the direction orthogonal to the traveling direction of the traveling carriage can be changed, the pitch between the fuel catching devices in the traveling direction of the traveling carriage cannot be changed.

Therefore, even if the fuel exchanger of JP-A-61-65192 is improved so that two fuel assemblies can be grasped and moved up and down at the same time, only a fuel exchanger having a small degree of freedom can be realized in relation to the fuel mounting pitch. There was a problem.
Since the fuel mounting pitch of the core and the fuel mounting pitch of the racks in the fuel storage pool are generally different, the pitch between the fuel gripping devices in the traveling vehicle traveling direction is determined as either the core or the rack in the fuel storage pool. It is necessary to fix at that pitch. That is, in the fuel exchanger of JP-A-61-65192,
There was a problem that two fuel assemblies could not be handled at the same time in the core and the racks in the fuel storage pool, and work efficiency could not be improved.

It is an object of the present invention to provide a refueling machine that can accommodate a wide range of core and pool fuel loading pitches.

[Means for solving problems]

In order to achieve the above object, the present invention provides a traveling vehicle that travels on a core and a fuel storage pool in a fuel exchanger that transfers a fuel assembly by a fuel gripping device between the core of a nuclear power plant and the fuel storage pool. And at least two lateral carriages each having one fuel gripping device and traveling on the traveling carriage in a direction orthogonal to the traveling direction of the traveling carriage, and mounted on the at least one lateral carriage. The present invention proposes a refueling machine provided with a traveling direction moving mechanism for adjusting a pitch between traveling fuel vehicles between traveling fuel gripping devices.

In order to achieve the above object, the present invention also runs on a core and a fuel storage pool in a fuel exchanger that transfers a fuel assembly by a fuel gripping device between the core of a nuclear power plant and the fuel storage pool. A traveling carriage, at least two lateral traveling carriages each having a fuel gripping device and traveling on the traveling carriage in a direction orthogonal to the traveling direction of the traveling carriage, and mounted on the at least one horizontal traveling carriage; A traveling direction moving mechanism that adjusts a pitch in the traveling direction of the traveling carriage between the fuel gripping devices is provided, and at least one of the lateral traveling carriages includes a plurality of fuel gripping devices, and a lateral traveling carriage including a plurality of fuel gripping devices. Each of them proposes a fuel exchange machine including a traveling direction moving mechanism for adjusting the pitch in the traveling direction of the traveling carriage between the plurality of fuel gripping devices on the transverse traveling carriage. Is shall.

[Action]

According to the first aspect of the present invention, since the traveling direction moving mechanism for adjusting the pitch in the traveling direction of the traveling vehicle between the fuel gripping devices mounted on at least one lateral traveling vehicle is provided, You can change the pitch significantly,
The movable width in which the adjustment range in the traveling direction of the traveling vehicle and the adjustment range in the direction orthogonal thereto is extremely wide, and at least two fuel assemblies arranged at various pitches can be handled at the same time.

In the second invention of the present invention, in addition to the configuration of the first invention, at least one of the lateral traveling carriages includes a plurality of fuel gripping devices, and each of the lateral traveling carriages including a plurality of fuel gripping devices is Since a traveling direction moving mechanism for adjusting the pitch in the traveling direction of the traveling carriage between the plurality of fuel gripping devices on the lateral traveling carriage is included, even on a lateral traveling carriage equipped with a plurality of fuel gripping devices by one unit, It is possible to change the pitch in the traveling direction of the traveling carriage between the plurality of fuel gripping devices provided there, and the movable range is extremely wide, which matches the adjustment range in the traveling direction of the traveling carriage and the direction orthogonal thereto, and it is arranged at various pitches. It is possible to handle at least two fuel assemblies simultaneously.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings, but before that, a loading state of a fuel assembly of a boiling water reactor will be described with reference to FIGS. 5 and 6.

FIG. 5 (A) shows a cross section of the core of a boiling water reactor.
In the figure, 1 is a fuel assembly, 2 is a control rod, and 3 is an LPRM.
(Local output detector). FIG. 5B shows a cell composed of four fuel assemblies 1 surrounding one control rod 2. The handles 1A of these four fuel assemblies 1 face each other so as to sandwich the control rod 2.

When a nuclear reactor is operated, the reactivity of the core is lowered, so that the spent fuel assembly must be periodically replaced with a new fuel assembly. The operation period of the nuclear reactor from the last refueling to the next refueling is called a cycle, and a new fuel assembly is exchanged at the end of each cycle. 1.1 million kW
The number of fuel assemblies in the core is approximately 800
It is a body, and it is necessary to replace 1/4 to 1/3 of the fuel assembly at every regular inspection.

FIG. 6 shows a loading pattern of the fuel assemblies 1 in the core of the boiling water reactor, that is, a state of arrangement of the fuel assemblies 1. The numbers 4 to 6 attached to each fuel assembly 1 are
Indicates the number of core stay cycles and shows the same number of fuel assemblies 1
Should be replaced at the same time.

A preferred embodiment of the fuel exchanger according to the present invention will be described with reference to FIGS.

The refueling machine 10 of the present embodiment includes one traveling carriage 16 and two lateral traveling carriages 17A and 17B traveling on a lateral traveling rail 19 laid on the traveling carriage 16 and lateral traveling carriages 17A and 17B.
Fuel grabs 30A and 30B attached to the
Further, the lateral traveling carriage 17B is provided with a movable carriage 41 movable in the traveling direction of the traveling carriage.

The fuel gripping device 30A has an expansion tube 11A in which a plurality of cylinders having different diameters are combined in the axial direction, and a fuel gripping tool (for example, a hook) 12A attached to the lower end of the expansion tube 11A. The fuel gripping device 30B includes an expansion tube 11B and an expansion tube 11B in which a plurality of cylinders having different diameters are axially combined.
Has a fuel gripping tool 12B attached to the lower end of the. Further, the fuel gripping device 30B is suspended by the moving carriage 41 installed on the upper portion of the lateral traveling carriage 17B, and moves following the movement of the moving carriage 41. As shown in FIG. 3, the moving carriage 41 includes wheels 42 at the lower portion thereof, and the moving carriage drive device 43 is provided.
The traveling carriage moves in the traveling direction by the fuel gripping device 30A.
You can adjust the fuel extraction pitch of the traveling carriage with the 30B and 30B.

Although not shown here, a plurality of telescopic tubes 11A and 11B are provided.
The drive unit that expands and contracts in the axial direction is
Attached to A and 17B. Drive devices for the fuel grippers 12A and 12B are also installed on the lateral traveling carriages 17A and 17B. The lateral traveling carriages 17A and 17B to which the fuel gripping devices 30A and 30B are attached can independently travel in the direction orthogonal to the traveling direction of the traveling carriage, and the fuel gripping devices 30A and 30B can be driven independently. it can. In this way, the lateral traveling carriage 17 is on the same rail 19 on the traveling carriage 16.
Since A and 17B move independently, a proximity sensor (not shown) is provided to prevent collision of the horizontal traveling carriages, and when the distance between the horizontal traveling carriages is within a specified value, stop their movement. A mechanism is provided on each lateral traveling carriage.

Further, since the fuel assemblies 1 are closest to each other when passing through the gate 18 to transfer the fuel assembly 1 from the core to the storage pool and vice versa, the gripping devices or the fuel assemblies may be shaken from each other. It is desirable to prevent the interference by providing a device for preventing the interference.

The refueling work using this embodiment will be described below. Here, the fuel assembly of the core 8 in the reactor pressure vessel 31 of the boiling water reactor is replaced by the fuel rack in the spent fuel storage pool 9.
The steps until transfer into 14 will be explained. At the time of refueling, the lid on the upper part of the reactor pressure vessel 31 is removed, and the cooling water 32 is filled up above the reactor pressure vessel 31 (FIG. 4).

By the traveling carriage 16 moving on the rail 33 installed on the 5th floor of the reactor building, after positioning the traveling carriage in the traveling direction based on the grip 12A of the gripping device 30A of the lateral carriage 17A, the lateral carriage 17A is positioned. Is moved to determine the position in the direction orthogonal to the traveling direction of the traveling carriage. At the same time, the horizontal carriage 17B is also moved, and the horizontal carriage 17B is further moved.
The upper traveling carriage 41 is moved in the traveling carriage traveling direction, and the fuel gripping device 30B of the lateral traveling carriage 17B is positioned in the traveling carriage traveling direction and the direction orthogonal to the traveling carriage traveling direction. Then, the expansion tube 11A of the fuel gripping devices 30A and 30B,
11B is extended downward, and fuel grippers 12A and 12B are simultaneously lowered. The descent of the fuel gripping tools 12A, 12B is stopped, and these are operated to simultaneously grip the handles of the two fuel assemblies 1. In that state, the expansion tubes 11A and 11B are contracted, and the horizontal traveling carriage 17
The fuel assembly 1 is lifted to a movable height of A and 17B.

Then, the horizontal traveling carriages 17A and 17B are connected to the fuel assembly 1 at the gate 1
As shown in FIG. 2, the traveling carriage 1 can pass through 8
Move to the center of 6. The gate 18 connects the pool above the core 8 and the spent fuel storage pool 9.

The two lifted fuel assemblies 1 are transferred to the spent fuel storage pool 9 through the gate 18 together with the fuel gripping devices 30A and 30B by the movement of the traveling carriage 16. After the traveling carriage 16 is moved and positioned on the basis of the lateral traveling carriage 17A on the predetermined fuel rack 14 in the spent fuel storage pool 9, the lateral traveling carriage 17A holds the fuel assembly 1 held by the fuel gripping device 30A. Is moved to the fuel rack 14 to be loaded and positioned. At the same time, the horizontal traveling carriage 17B
As the vehicle moves, the moving carriage 41 on the horizontal traveling carriage 17B moves in the traveling direction of the traveling carriage, and on the fuel storage rack 14 to mount the fuel assembly held by the fuel gripping device 30B of the horizontal traveling carriage 17B. Then, positioning is performed in the traveling direction of the traveling vehicle and the direction orthogonal to the traveling direction of the traveling vehicle. Here, the expansion tubes 11A and 11B are extended to accommodate the two fuel assemblies in the fuel storage rack 14 at the same time and remove them from the fuel grips 12A and 12B. After that, the fuel gripper 12A, 12B
To a height where the refueling machine can move. In addition, the expansion tubes 11A and 11B of the fuel gripping devices 30A and 30B are connected to the gate 18
The lateral traveling carriages 17A and 17B are moved to a position where the vehicle can pass through. The refueling machine 10 passes through the gate 18 and moves to the position of the fuel assembly in the core 8 to be replaced next, and one step of refueling is completed. In the refueling machine 10, the traveling carriage 16, the restraining traveling carriages 17A and 17B, the fuel grip 12
The A, 12B and the mobile carriage 41 have a self-determining function so as to operate in the most rational procedure according to the refueling plan by a computer that controls the entire refueling machine 10.

In this embodiment, the case where the number of the lateral traveling carriages is two has been described.
Of course, three or more units may be used.

In addition, at least one of the plurality of traveling carriages has two
If two fuel gripping devices 30 are attached and one of them is provided with a mechanism that can be finely adjusted in the traveling direction of the traveling carriage with respect to the other, in addition to the advantages of the above embodiment, a fuel exchanger capable of simultaneously transferring a large number of fuel assemblies. Is obtained.

〔The invention's effect〕

According to the present invention, in a fuel exchanger capable of simultaneously transferring a plurality of fuel assemblies, the traveling direction between the fuel gripping devices and the pitch in the direction orthogonal to the traveling direction of the traveling car can be freely changed. In comparison with the above, various fuel assemblies can be handled, and in particular, a refueling machine suitable for refueling work of a high conversion reactor which is being recently developed can be obtained.

As a result, the refueling work time can be further shortened, the periodic inspection period can be shortened, and the operating rate of the nuclear power plant or the like can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a fuel exchanger according to the present invention,
FIG. 2 is a plan view of the fuel exchanger of FIG. 1, FIG. 3 is a view showing the details of the structure of the lateral traveling vehicle of the embodiment of FIG. 1, and FIG.
Figure Explanatory view of refueling work by refueling machine, Figure 5 (A) is a plan view of the core of a boiling water reactor, Figure 5 (B)
FIG. 5 is an enlarged view of part A of FIG. 5 (A), and FIG. 6 is a view showing a loading pattern of the fuel assemblies loaded in the core of FIG. 5 (A). 1 ... Fuel assembly, 2 ... Control rod, 3 ... LPRM (local power detector), 4-6 ... Fuel assembly stay cycle number in the reactor, 7 ... Cell, 8 ... Core, 9 ... … Fuel storage pool,
10 …… Refuel exchange machine, 11A, 11B …… Fuel gripping device expansion tube, 12A, 12B …… Fuel gripping tool, 14 …… Fuel storage rack, 16 …… Truck truck, 17A, 17B …… Traverse truck, 18… …
Gate, 19 ... Horizontal traveling rail, 30A, 30B ... Fuel gripping device, 40 ... Fixed carriage, 41 ... Moving carriage, 42 ... Wheels,
43 …… Mobile cart drive, 44 …… Wire rope, 45 ……
Wire winding device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Koizumi 3-1-1 Sachimachi, Hitachi City, Ibaraki Pref., Hitachi Works, Hitachi Works (56) References JP-A-61-65192 (JP, A)

Claims (2)

[Claims] 1. A fuel exchanging machine for transferring a fuel assembly by a fuel gripping device between a core of a nuclear power plant and a fuel storage pool, wherein a traveling carriage that travels on the core and the fuel storage pool, At least two lateral traveling carriages each having a gripping device and traveling on the traveling carriage in a direction orthogonal to the traveling direction of the traveling carriage; and at least one lateral traveling carriage mounted on the lateral traveling carriage. And a traveling direction moving mechanism that adjusts a pitch between the gripping devices in the traveling direction of the traveling carriage. 2. A fuel exchanger for transferring a fuel assembly by a fuel gripping device between a core of a nuclear power plant and a fuel storage pool, wherein a traveling carriage that travels on the core and the fuel storage pool, each of which comprises the fuel. Between at least two lateral traveling carriages having a gripping device and traveling on the traveling carriage in a direction orthogonal to the traveling direction of the traveling carriage, and between the fuel gripping device mounted on at least one of the lateral traveling carriages. And a traveling direction moving mechanism for adjusting a pitch in the traveling direction of the traveling carriage, wherein at least one of the lateral traveling carriages has a plurality of fuel gripping devices, and each of the lateral traveling carriages having a plurality of fuel gripping devices. Includes a traveling direction moving mechanism for adjusting a pitch in the traveling direction of the traveling carriage between the plurality of fuel gripping devices on the lateral traveling carriage. Refueling machine which is characterized.