JPS6157894A - Spent material housing basket for nuclear reactor - Google Patents

Abstract

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

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a nuclear reactor spent material storage basket for storing residues resulting from sampling spent nuclear reactor material in a fuel pool.

[Technical background of the invention and its problems]

Generally, when replacing piping in the reactor core at a nuclear reactor facility, the used piping is stored in a fuel pool and allowed to decay for about six months before being disposed of in the waste treatment system. being done. When measuring the dose of irradiated piping stored in a fuel pool, the piping is cut into multiple pieces corresponding to the measurement points, and these are stored in baskets and lead-protected casks. Transport it to the materials testing room using Most of this work is done inside the fuel pool to minimize radiation exposure.

By the way, when the used piping is a long pipe, samples are collected only from necessary locations, resulting in a large amount of residual material. For this reason, these residual materials are scattered within the fuel pool, which may cause problems in the management and operation of the fuel pool.

[Purpose of the invention]

The present invention was made based on these circumstances,
Its purpose is to prevent waste materials from being scattered randomly in the fuel pool when sampling irradiated materials, and to provide a safe and easy way to handle waste materials from nuclear reactors. It's about providing baskets.

[Summary of the invention]

The present invention is a basket for containing residue from sampling of used materials in a fuel pool, and is constructed as follows.

That is, the basket includes a bottomed cylindrical basket body that is installed in a fuel pool with a drain hole provided at the bottom and the opening facing upward; A lid body provided with a lower member, and a lid body placed in the opening of the basket body from above, are rotated about the axis of the basket body to close the basket body. The device is equipped with a locking mechanism for fixing the device to the device.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In Figure 1, reference numeral 1 indicates a fuel pool with a depth of about 10 m, for example, which is installed adjacent to the pressure vessel of a nuclear reactor facility, and used materials such as reactor piping are collected in water 2 filled with water inside the pool. Stored for a specified period of time. To move the spent material from the core to the fuel pool 1,
This is done by a gripping mechanism 3 that is movable in the space above the .

Inside the fuel pool 1, a plurality of used material storage baskets (hereinafter referred to as "remaining material baskets") 4 according to this embodiment are accommodated.

This leftover material basket 4 is specifically constructed as shown in FIGS. 2 to 4.

That is, this leftover material basket 4 has a basket main body which is formed into a cylinder shape with a bottom, a lid which closes the opening of the basket main body, and a lid which is fixed to the basket main body. The lid U- is comprised of a locking mechanism and a locking mechanism for fixing the lid U- to the main body.

The basket main body is constructed by fixing, for example, by welding, a guide member 18 for guiding the lid 12 to the opening of a bottomed cylindrical body 17 having a plurality of drainage holes 16 at the bottom. The bottomed cylindrical body 17 has an outer diameter of, for example, 500~
It is made of aluminum, stainless steel, etc. and is 600 mm long and 4.5 m high. The guide member 18 includes a collar-shaped portion 21 extending radially outward from the opening of the bottomed cylinder 17, a portion 22 rising upward in the figure from the collar-shaped portion 21, and this portion 22. It further comprises a collar-shaped portion 23 extending inward in the radial direction of the bottomed cylindrical body 17.

That is, these portions 21 to 23 are formed to have a U-shaped cross section, and a guide groove 24 is formed inside the portions. The brim-shaped portion 23 has four notches 25a, 25 equally distributed in the circumferential direction and extending from the inner circumferential side to the outer circumferential side.
b, 25c, 25d are formed. Groove 2
4, at the position between the notch 25b and the notch 25c,
A stopper 26 formed by bending a flat plate is attached. This stopper 26 has an end fixed to the side surface of the bottomed cylindrical body 17 with a bolt 27 . In addition, at opposing positions near the bottom on the side surface of the bottomed cylindrical body 17, hanging ears 28a are formed by bending rod-shaped members.

28b is fixed, and these hanging ears 28a, 2
For example, a loaf 29 is hooked to 8b.

On the upper surface of the brim-shaped portion 23, the notch 25a and the notch 2
5, a base end portion of a locking mechanism body 30, which will be described later, is fixed by a bolt 31.

The tip of the locking mechanism main body 3o protrudes toward the center of the bottomed cylindrical body 17. Since the distal end side of the locking mechanism main body 30 is an important part that controls the locking operation, its upper surface is covered with a cover 32. This cover 32 is disposed on both sides of the locking mechanism main body 30, and its base end is fixed to the upper surface of the cap-shaped portion 23 with bolts 33. There is.

The lid body includes a disc-shaped lid body 37 and this lid body 37.
Suspension members 38 fixed at opposing positions on the outer periphery of the upper surface of
a, 38b. The lid main body 37 is
At its outer periphery, there are cutout portions 25a to 25a of the basket main body.
25d, four equally spaced protrusions 39a, 39b extending radially outward, such that the protrusions 39a, 39b can be fitted with the protrusions 25d.

39c and 39d. In addition, the lid body 37
A notch 40 is provided between the protrusion 39a and the protrusion 39d and extends inward in the radial direction and is large enough to pass through the cover 32 of the locking mechanism 30 in the vertical direction in the figure. Note that a hanging rope 41 is hooked to the hanging members 38a and 38b.

A square piece 43 is fixed to the center of the lid main body 37 with a bolt 44. Square dust 43 has four corners with protrusions 39
The protrusion 39a is arranged toward a to 39d.

The corner toward 39c is thinned to form a flat surface.

A locking mechanism U is constituted by this square dust 43 and the locking mechanism main body 30. The lock mechanism main body 30 has a fourth
It is configured as shown in the figure. That is, numeral 46 in the figure is a rectangular cylindrical body whose tip end is narrowed. A coil spring 47 is housed inside this body 46 . The proximal end of the coil spring 47 is fixed by a push screw 48 attached to the body 46, and the distal end of the coil spring 47 supports a chuck 49. A V-groove 50 is formed at the tip of the chuck 49 so as to fit into a corner of the square dust 44.

Next, the operation of the leftover material basket 4 configured as described above will be explained.

That is, the used material removed from the core by the gripping mechanism 3 is temporarily stored in the fuel pool 1. When measuring the dose of the used material as needed, the material is cut at the required location and a sample is collected. At this time, since the leftover material basket 4 is placed in the fuel pool 1, the cutting operation is performed at the upper part of the opening of the leftover material basket 4 with the lid removed. Therefore, the residual material resulting from sample collection is
The leftover materials are sequentially stored inside this basket 4.

When all the remaining materials are stored, operate the gripping mechanism 3 to move the lid to the opening position of the basket body, and press each protrusion 39a to 39d of the lid and each notch of the basket body. 25a to 25d, and align the projections 3.
9a to 39 (I) are superimposed on the upper surface of the brim-like portion 21, the lid body is placed on the basket body.Next, when the lid body ratio is rotated clockwise by the gripping mechanism 3, the lid body is placed on the basket body. During operation, the protrusions 39a to 39d are guided by the guide groove 24 and rotate.

As a result, the tip of the chuck 49 of the locking mechanism V- gradually releases the coil spring 47 while slidingly contacting the square dust 43.
Move in the direction of energizing. When the lid U is rotated by 45 degrees, the corners of the square dust 43 fit into the V grooves 50 of the chuck 49. At this time, the tip of the protrusion 39b rides on the stopper 26 and presses the lid 12 in a direction that causes the coil spring 47 to further contract. As a result, the basket main body and the lid U- are in a locked state. Therefore, if the row 141 connected to the lid body is pulled up in this state, the remaining material basket 4
can be moved in the fuel pool 1 and can also be withdrawn from the fuel pool 1. In addition, when pulling up the remaining material baskets 1 to 4 from the fuel pool 1, the drain hole 16 provided at the bottom of the basket body and the notch 40 formed in the lid body are removed from the inside of the remaining material basket 4. Contributes to draining water. Also, the lobes 29 connected to the hanging ears 28a, 28b are used to tilt the scrap basket 4.

In this way, according to the present embodiment, the remaining materials can be stored in the fuel pool 1 in one predetermined category, which is convenient for managing the remaining materials. Furthermore, since the leftover material basket 4 is provided with the lid R, there is little risk of different leftover materials being mixed into the same basket.

In addition, since the lid body ratio and the basket body ratio are fixed by the lock mechanism U, the lid body ratio is fixed to the leftover material basket 4.
It can be used as a mechanism for moving. In this case, all the attachment and detachment of the lid can be easily performed from above the fuel pool 1, so that the amount of radiation exposure caused by this can be kept extremely small.

〔Effect of the invention〕

As described above, according to the present invention, the remaining materials generated by collecting samples of used materials from nuclear reactors can be stored together in predetermined categories without being scattered in the fuel pool. Many management benefits can be obtained, such as understanding the

Further, the lid can be attached and removed from above the fuel pool, and since a suspension member for the lid is provided, the basket can be easily moved by suspending the lid. Therefore, highly safe work with low radiation exposure can be performed.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a used material storage basket according to an embodiment of the present invention arranged in a fuel boule, FIGS. 2 to 4 are diagrams showing the same basket, and FIG. 2 shows the entire basket. FIG. 3 is a partially cutaway exploded perspective view, and FIG. 4 is a partially cutaway view of the locking mechanism of the basket 1 as seen in the direction of the arrow. 1...Fuel pool, 2...Water, 3...Gripping mechanism,
4... Used material storage basket, 11-... Basket body, 12... Lid body, U... Lock mechanism,
16... Drain hole, 17... Bottomed cylindrical body, 18...
・Guidance part O, 21.23...Brim shape 2.
Part, 24... Guide groove, 25a-25d... Notch, 26... Stopper, 28a, 28b... Hanging ear, 29. /11...Rope, 30...Lock mechanism body, 32...Cover, 34...Seat for installation, 37
... Lid body, 38a, 38b... Hanging member,
39a-39d...Protrusion, 40...Notch, 43.
...For square shapes, 46...Body, 47...Coil spring, 48...Push screw, 49...Jack, 50...
・V groove.

Claims (1)

[Claims] A cylindrical basket body with a bottom and installed in a fuel pool with a drain hole at the bottom and an opening facing upward, and a lid body that closes the opening of the basket body and is provided with a hanging member. , a locking mechanism for fixing the lid placed in the opening of the basket body from above the opening to the basket body by rotating the lid around the axis of the basket body. A spent material storage basket for a nuclear reactor.