JPS5932893A - Shoot type fuel charging device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel transfer device between an external fuel storage tank and a nuclear reactor in a loop-type or tank-type fast breeder reactor. significantly shorten the
This invention relates to a chute-type fuel inlet/output device designed to improve reliability.

Conventionally, the structure of this type of fuel inlet/output device, as shown in FIG. 1, consists of a reactor vessel 1, a reactor core 2, a fuel exchanger 3, an in-core chute 4, an out-of-core chute 5, an out-of-core fuel storage tank 6, etc. ing.

In the above reactor, new and spent fuel is transferred in and out as follows.

First, spent fuel is extracted from the core 2 by the fuel exchanger 3 and inserted into the bucket 7 provided at the lower end of the in-core chute 4 . The bucket 7 is fixed to the truck, and connected to the rigging of a drive mechanism 9 installed above the in-furnace chute 4 and above the transfer tube 8. 7 can be pulled up to the position of the transfer cylinder 8.

At this time, the truck to which the bucket 7 is fixed during driving is pulled up along the rail 10 provided in the in-furnace chute 4.

When the spent fuel is lifted up into the transfer tube 8, the transfer tube 8 and drive mechanism 9 are swung around the fulcrum 12 on the central axis of the external chute 5. In this figure, a so-called swing type operation is explained, but there is also an example in which this operation is performed by a rotation type.

When the transfer cylinder 8 has been swung onto the central axis of the outside chute 5, the drive mechanism 9 is driven to move the cart to which the bucket 7 is fixed along the rail 11 provided on the outside chute 5 to a position where it stands upright at its lower end. The fuel is unloaded and transferred to a storage rack 16 using a fuel transfer device 15 provided in the out-of-core fuel storage tank 6.

Next, new fuel is pulled out from the storage rack 16, transferred to the bucket 7, passed through the out-of-furnace chute 5, and pulled up to the transfer tube 8. The transfer tube 8 is swung onto the central axis of the in-furnace chute 4, and the new fuel is passed through the in-furnace chute 4. It is moved to a specified position in the reactor and transferred to the reactor core 2 using the fuel exchanger 3. 13 and 14 in the figure
is a gate valve that closes when not needed and forms the boundary between the reactor and containment vessel C.

However, in the conventional chute-type fuel inlet/output device described above, when one chute is in use, the other chute cannot be used, so exchanging multiple fuel can take a long time and is not efficient. In addition, the driving force when lowering the trolley with the bucket 7 fixed can only be obtained from its own weight, so if the lowering drag of the trolley increases due to Na (sodium) adhesion to the rail 11 or thermal distortion of the rail 11, etc. ,
There were drawbacks such as difficulty in stable driving.

The present invention was made in order to solve the above-mentioned conventional drawbacks, and in addition to making it easy to exchange multiple fuels in a short time, the present invention also enables forced drive even when descending, since it drives a truck with fixed buckets. The present invention provides a chute-type fuel inlet/output device which is configured so that no trouble occurs even if Na fixation occurs.

Hereinafter, embodiments according to the present invention will be described in detail based on FIGS. 2 to 6.

FIG. 2 is a sectional view of a main part of a chute-type fuel inlet/output device showing an embodiment of the present invention, and in the figure, parts corresponding to the conventional structure are given the same reference numerals and explanations are omitted.

20 is a drive equipment, 21a and 21b are relay tubes with an opening at the bottom, and each has a pot pulling device 22a at the top.
, 22b, and these pairs of relay tubes 21a, 21
b can be rotated by 180° around the rotation axis 23.

Both new fuel and spent fuel are put into a suitable pot during transfer, and the pot extraction devices 22a and 22b have a gripper and a hoisting device, grip the pot containing fuel with the gripper, and move it to the relay tube 21a or 21b using a hoisting device, and also has a function of suspending it from the bucket 7a or 7b located directly below the relay tubes 21a and 21b.

The inner chute 4 and the outer chute 5 have rails 10 and 11.
A conveyor chain 24 that engages with these rails 10 and 11 is laid down, and buckets 7a and 7b that accommodate fuel pots are attached to both ends of the conveyor chain 24.

The buckets 7a and 7b are mounted so that one is at the lower end and the other is at the upper end, and see-saws with the sprocket 25.

The rails 10, 11 have buckets 7a, 7b standing upright at the lower end and are aligned with the conventional fuel exchanger 3 and fuel transfer device 15, and buckets 7a, 7b at the upper end stand upright at the relay tubes 21a, 21.
Place it so that it is located on the axis of b.

Furthermore, the rail 11 outside the furnace is configured to be switched to a rail 28 installed in a conveyor chain storage container 27 by a switching device 26.

The conveyor chain 24 used in the above-mentioned device is a special backstop type chain shown in FIG.
Select materials that can withstand use in (a) (sodium).

That is, as shown in FIG. 5, the conveyor chain 24 is composed of links 29, floor rollers 30, pins 31, etc., and since the floor rollers 30 move while being restrained by the rails 10, 11 and 28, they are driven by the sprockets 25. Then you can force push and pull.

In addition, if the rail switching device 26 is aligned with the rail 11 side at the upper end position of the bucket 7b, fuel exchange work becomes possible.
When aligned on the rail 28 side, the bucket 7b and the conveyor chain 24 are accommodated in the conveyor chain storage container 27, and the gate valves 13 and 14 shown in FIG. 2 can be closed.

Next, the operation of the apparatus configured as described above will be explained with reference to FIG. 2.

Incidentally, fuel transfer between the core 2 and the bucket 7a and between the bucket 7b and the storage rack 16 in the figure is performed by the fuel exchanger 3 and the fuel transfer device 15 shown in FIG. 1, as in the conventional art.

First, before fuel exchange, the bucket 7b is located at the bottom of the conveyor chain storage container 27, the bucket 7a is located directly below the relay tube 21a, and the gate valves 13 and 14 are closed.
First, open the gate valves l3 and 14, operate the sprocket 25, and place the bucket 7a at the fuel delivery position in the furnace, and the bucket 7b.
is moved directly below the relay tube 21b, and the switching device 26 sets the rail to the 11 side.

The sprocket 25 is operated, the bucket 7b is moved to the fuel delivery position of the extra-core fuel storage tank 6, and new fuel is transferred to the bucket 7b.
b, actuate the sprocket 25 again, move the bucket 7b directly below the relay tube 21b, and remove the pot from the pot extraction device 22.
new fuel is pulled up to the relay cylinder 21b by b. At the same time, since the bucket 7b is located at the fuel delivery position within the reactor, it receives the spent fuel. Next, the sprocket 25 is rotated in the opposite direction to raise the bucket 7a directly below the relay tube 21a, the spent fuel is stored in the relay tube 21a, and the drive equipment 20 changes the positions of the relay tubes 21a and 21b to transfer new fuel into the bucket 7a. Move.

During this operation, fresh fuel from storage rack 16 is transferred to bucket 7b. While returning the relay tubes 21a, 21b to their original positions, pull up the bucket 7b, store new fuel in the relay tube 21b, replace the positions of the relay tubes 21a, 21b, and transfer the spent fuel stored in the relay tube 21b into the bucket. Move to 7b. The same operation is repeated, and when the fuel exchange is completed, both buckets 7a and 7b are empty as shown in FIG. When the bucket 7a is lowered to the lower end of the gate valve 13, the bucket 7a is located directly below the relay pipe 21a.
, 14 are closed, and the fuel exchange work is completed.

As described in detail above, since the chute-type fuel inlet/output device according to the present invention has a relay device installed outside the reactor vessel, multiple fuel exchange operations can be performed simultaneously, and the exchange time can be significantly shortened.

In addition, one trolley with fixed buckets was installed outside the furnace and one inside the furnace, and these were fixed to both ends of a backstop-type conveyor chain and were configured to be driven by a sprocket installed at the top of the chute. It is also possible to forcibly push in, making stable driving possible.

Furthermore, since a conveyor chain storage pit is provided, maintenance is easy and the drawbacks of conventional rice-clamping equipment are overcome.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing a conventional chute-type fuel inlet/output device.
Fig. 2 is a sectional view showing the chute type fuel inlet/output device according to the present invention, Fig. 3 is a detailed view around the conveyor chain according to the invention, Fig. 4 is a sectional view taken along line AA in Fig. 3, and Fig. 5 is a sectional view showing the area around the conveyor chain according to the invention. 3 is a view taken along arrow B in FIG. 3, and FIG. 6 is a sectional view taken along line C-C in FIG. 3. DESCRIPTION OF SYMBOLS 1... Reactor vessel, 2... Reactor core, 3... Fuel exchange machine, 4... In-reactor chute, 5... Out-of-core chute, 6
... Ex-core fuel storage tank, 7a, 7b... Bucket, 10
, 11... Rail, 12... Fulcrum, 13, 14...
- Gate valve, 15...Fuel transfer device, 16...Storage rack, 20...Drive equipment, 21a, 21b...Relay tube, 22a, 22b...Pot extraction device, 23...Rotating shaft , 24... Conveyor chain, 25... Sprocket, 26... Switching machine, 27... Conveyor chain storage container, 28... Rail, 29... Link, 30
...Floor roller, 31...pin.

Claims (1)

[Claims] In a chute-type fuel inlet/output device for a liquid metal cooled fast breeder reactor, a backstop type conveyor chain is provided with a relay device of a relay tube at the top of the chute and engages with a rail as a mechanism for a bucket that transfers fuel through the chute. A rail switching device was installed to enable closing of the inner and outer reactor chute during reactor operation, and the reactor outer bucket and conveyor chain were configured to be transferred to a container other than the chute at the same time as the fuel exchange was completed. A chute-type fuel inlet/output device featuring: