JPH0469598A - Fuel storage device for nuclear reactor - Google Patents

Abstract

PURPOSE:To increase fuel storage capacity greatly by providing plural pool floors and a travel carriage which travels on a travel path provided on those pool floors. CONSTITUTION:An elevation device 16 is used to move the travel carriage 14 to a pool floor 11, 12, or 13 from which fuel is removed, and the travel carriage 14 is moved to a desired place along the travel rail 14. After operation, a fuel rack 17 on the travel carriage 14 is held and stored at a programmed specific position on the pool 11, 12, or 13. Thus, the pool floors 11, 12, and 13 are provided in a fuel storage pool 2, so the storage capacity can be increased greatly.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention mainly relates to a nuclear reactor fuel for temporarily storing spent fuel assemblies taken out from a nuclear reactor in a fuel storage pool. The present invention relates to storage devices, and particularly to improvements in storage methods thereof.

(Prior art) Generally, in nuclear power plants, after a period of operation, spent fuel is taken out of the reactor, cooled and stored in a fuel pool, and the decay heat of the fuel is removed. .

FIG. 4 shows a conventional fuel storage device for a nuclear reactor used in this case. In the figure, reference numeral 1 is a reactor pit, and a fuel storage pool 2 is adjacent to the reactor pit 1. A cask pit 3 is provided in one corner of the fuel storage pool 2 in which a cask for handling activated equipment is installed. The spent fuel is accommodated and stored in a fuel rack 4 installed in the fuel storage pool 2.

The rack 4, as shown in FIG. It is fixed to the pool floor 7 with mounting bolts 8.

(Problems to be Solved by the Invention) In the conventional fuel storage system for nuclear reactors, spent fuel is stored in each rectangular cylinder 5 of the fuel rack 4 fixed to the pool floor 7. As the number of years of plant operation has passed, the number of spent fuels stored within the plant has increased, and in conjunction with trends in fuel cycle facility planning, fuel storage pool 2 has recently received an increase in storage capacity. The need is increasing.

For this reason, various efforts have been made to increase the number of fuels stored in the fuel storage pool 2. A typical example is a dense rack in which the pitch between the fuel rack 40 rectangular cylinders 5 is made as small as possible. In recent years, plans have been made to improve this dense rack by using boron-added stainless steel to make it even more dense. Furthermore, some methods have also been proposed in which the fuel racks 4 are stacked one above the other, as shown in, for example, Japanese Unexamined Patent Publication No. Sho 60-13292.

However, the conventional method has a problem in that there is a limit to densification and it is difficult to meet the demand for further increase in storage capacity. Furthermore, since the fuel rack 4 is fixed on the pool floor 7 with mounting bolts 8, there is a problem in that it lacks elasticity in order to efficiently temporarily store core components other than fuel.

The present invention was made in consideration of the above-mentioned circumstances, and it is possible to significantly increase the temporary storage capacity of spent fuel, and also to efficiently store reactor core components other than fuel. The purpose of the present invention is to provide a fuel storage device for a reactor.

[Structure of the invention]

(Means for Solving the Problems) In order to solve the above problems, a nuclear reactor fuel storage device according to the present invention stores spent fuel assemblies taken out from a nuclear reactor in a fuel storage rack. In a nuclear reactor fuel storage device for storing fuel in a fuel storage pool, a plurality of pool floors are provided in a multi-story structure in the fuel storage pool, and a running cart that runs on a running path provided on each of these pool floors; a lifting device that moves the traveling cart between upper and lower pool floors; a moving device that moves the fuel storage rack within each pool floor; and a holding mechanism that prevents the fuel storage rack stored on each pool floor from falling over. , and a monitoring device that remotely monitors each pool floor.

(Function) In the fuel storage device for a nuclear reactor according to the present invention, spent fuel assemblies taken out from the reactor are stored in fuel storage racks and stored in a multi-story structure in a fuel storage pool. Each is stored on the pool floor. Therefore, compared to conventional methods, it is possible to significantly increase the storage capacity.

In addition, when loading and unloading fuel according to the fuel exchange plan, first the traveling vehicle is moved to a predetermined pool floor using the lifting device, and then the traveling vehicle is moved to the desired location along the travel path on the pool floor. Thereafter, the fuel storage rack is pulled out and held on the running road or on the running trolley by a moving device,
Carry out necessary fuel loading and unloading. After completion of the work, the fuel storage rack on the traveling trolley is held and stored in a predetermined position on the planned pool floor. These operations can be monitored remotely using a monitoring device, so they can be carried out safely and reliably.Furthermore, the fuel storage rack is not fixed to the pool floor, but is held by a holding mechanism, so it is easy to use. It is also possible to flexibly operate core components other than finished fuel, making it possible to flexibly respond to various changes in the number of stored fuels and the storage composition ratio.

(Example) An example of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 is a plan view showing an example of a nuclear reactor fuel storage device according to the present invention, and in the figure, reference numeral 1 indicates a reactor pit. A fuel storage pool 2 is provided adjacent to this reactor pit l, and in one corner of this fuel storage pool 2,
A cask pit 3 is provided for a cask that handles activated equipment.

As shown in FIG. 2, the fuel storage pool 2 includes, for example, a pool floor 11 having a three-story structure. 12. 13 are provided respectively, and the bedding is determined by taking into consideration the required fuel storage capacity of the power plant.

In the center of each of these pool floors 11, 12, 13, a first
As shown in FIG. 2, each pool floor 11, 12.
Traveling rails 15 on which a common traveling trolley 14 runs are installed at the end portions of the traveling rails 13 and 13, respectively, and as shown in FIG. A lifting device 16 is installed at 12.13 for lifting and lowering.

As partially shown in FIGS. 1 and 2, fuel racks 17, which will be described later, are installed on both sides of each of the pool floors 11, 12, 13 via the running rails 15.
A slider 18 is installed to move the fuel rack 17 in a direction perpendicular to the running direction, and each fuel rack 17 is fitted into a groove of the slider 18 to be moved, held, and stored.

That is, as shown in FIG. 3, the inside of the fuel rack 17 is partitioned into a lattice shape by rectangular square tubes (not shown) so that a plurality of fuels can be stored therein. A constricted portion is provided in the portion, and a flange-shaped base 19 is integrally provided at the lower end of this constricted portion.

On the other hand, as shown in FIG. 3, the slider 18 includes a pair of rail members 18a having a generally U-shaped cross section with openings facing each other;
18a, each of these rail members 18a,
18a connects each pool floor 11,
It is fixed on 12.13. Each rail member 18a,
Roller bearings 21 are installed at the bottom of each of the roller bearings 18a. The base 19 of the fuel rack 17 is moved, held and stored along the slider 18 with both ends thereof fitted into rail members 18a, 18a on both sides, and when stored,
The fuel rack 17 has a structure in which upper end portions on both sides are held by holders 22 to prevent it from falling over.

As shown in FIG. 2, within the fuel storage pool 2, there is also a monitoring device 23 suspended from the running rail 6 portion of each pool floor 11, 12.13. The status of various equipment on the floor pools 11, 12, and 13 can be monitored remotely.

Next, the operation of this embodiment will be explained.

When handling fuel, first use the lifting device 16 to move the carriage 14 to the pool floor 11.12 or 13 from which the fuel has been removed;
The traveling carriage 14 is moved along the traveling rails 15 to a desired location.

After moving the traveling cart 14 to a desired location, move the adjacent fuel rack 17 along the slider 18 to the traveling rail 1.
5 or on the traveling trolley 14 and hold it there.

In this state, the necessary fuel is put in and taken out according to the fuel exchange plan, and after the work is completed, the fuel rack 17 on the traveling trolley 14 (in various forms depending on the fuel plan, such as one filled with fuel or empty) ) Planned pool floor 11.
12 or 13 is held and stored in a predetermined position.

Since a plurality of pool floors 11, 12, 13 are provided in the fuel storage pool 2 in a multi-story structure, the storage capacity can be significantly increased compared to the conventional method.

In addition, the fuel rack 17 is not fixed to the pool floor 11, 12゜13 and can be moved freely, so the number of stored fuel racks and the storage composition ratio can be changed, including core components other than spent fuel. It can flexibly deal with various fluctuations and make storage capacity more flexible.

〔Effect of the invention〕

As explained above, according to the present invention, a plurality of pool floors are provided in the fuel storage pool in a multi-story structure, so that
Fuel storage capacity can be significantly increased.

In addition, since the fuel storage rack is not fixed on the pool floor, it can efficiently store not only used fuel but also other core components, and can flexibly respond to changes in the number of fuels stored and the storage composition ratio. 3°, and the holding mechanism allows
Fuel storage racks can be stored stably.

Additionally, each pool floor can be monitored remotely using a monitoring device, ensuring work safety.

1 floor, 14... running trolley, 15... running rail,
16... Lifting device, 17... Fuel rack, 18...
- Slider, 22... Holder, 23... Monitoring device.

Claims (1)

[Claims] In a nuclear reactor fuel storage device for storing spent fuel assemblies taken out from a nuclear reactor in a fuel storage pool while being housed in a fuel storage rack, the fuel storage device is provided in a multi-story structure in the fuel storage pool. A plurality of pool floors, a traveling truck that travels on a traveling path provided on each pool floor, and a lifting device that moves the traveling truck between the upper and lower pool floors;
A moving device for moving the fuel storage rack within each pool floor, a holding mechanism for preventing the fuel storage rack stored on each pool floor from falling over, and a monitoring device for remotely monitoring each pool floor. A nuclear reactor fuel storage device characterized by: