JPH0249599Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a structure that allows the spent fuel inserts to be easily taken out from the storage basket.

Currently, most of the non-flammable radioactive solid waste generated from nuclear facilities is temporarily stored in untreated storage or underwater in pits.
These wastes continue to accumulate, and the storage capacity of storage bins or pits is becoming a problem.
Therefore, in order to improve this storage efficiency, waste volume reduction treatment is being implemented. Volume reduction methods include disassembly, compression, fragmentation, and melting. Disassembly methods include separating the waste by cutting or removing fasteners, and tightly bundling the separated parts or tightly placing them in storage containers. It is designed to reduce the volume by storing it.

Fuel inserts, such as burnable poison aggregates used in pressurized water reactors, have traditionally been stored in pits as they are after use, which significantly reduces pit storage efficiency. Ta. The above poison aggregate has a diameter of approximately 10 mm and a length of 4
10 to 20 rods of 1.5 m in diameter are attached to the holder at a pitch of about 40 mm, so if this is disassembled and stored in a basket, the volume can be reduced to about 1/10.

The waste stored in the basket has been reduced in volume and is efficiently stored in storage or in water in a pit, but this is only interim storage and not permanent disposal. That is, the waste stored in the basket needs to be taken out again for further processing (for example, solidification), and therefore the basket needs to have a structure that allows the stored items to be taken out. However, in the past, the materials were simply stored tightly in a basket, making it very time-consuming to take them out.

This invention was devised in order to overcome these conventional drawbacks, and it is possible to tightly store waste in a basket and also to allow the waste to be easily taken out. In other words, this device is a basket whose interior is divided into small compartments to store slender waste in close proximity to each other, the top of which is open, and each slender waste is inserted one by one into each compartment. The basket is provided with means at the bottom of the basket that are arranged vertically and project upwardly by different amounts.

Hereinafter, embodiments of this invention will be described with reference to the drawings. In FIG. 1, a basket 1 is formed into a box shape with an open top surface by side walls 2 and a bottom wall (not shown), and inside the basket 1 is formed into a large number of compartments by vertical and horizontal partition plates 3. Each compartment has a A poison rod 4 is inserted in the vertical direction. Fig. 2 shows another example of the basket, in which guide tubes 5 are tightly packed in place of the partition plate 3 in the basket 1 so that they do not move relative to each other, and the insides of these guide tubes 5 are filled with holes for poison rods 4. It is divided into sections. By forming a large number of compartments in the basket 1 in this manner, it is possible to insert the long and thin poison rods 4 cut from the poison aggregate one by one and store them in a dense manner. If partitions are not formed, each poison rod 4 will bend when inserted one by one.
Otherwise, it is difficult to insert multiple poison rods due to falling.

In the stored state, the upper ends of each poison rod 4 are located at the same height and close to each other, so it is very difficult to take out the poison rods 4 one by one during reprocessing. Therefore, as shown in FIG. 3, means is provided at the bottom of the basket 1 to vary the amount of protrusion of the upper end of the poison rod 4.
That is, a hole 7 having a diameter smaller than the diameter of the poison rod 4 is formed in each section in the bottom plate 6 of the basket 1, and a protruding means 8 is provided separately from the basket 1. This protruding means 8 is formed by protruding rods 81 having different lengths from each other on a substrate 80.
1 has a smaller diameter than the hole 7 and is arranged to correspond to the hole 7. When the basket 1 is moved and lowered onto the protruding means 8 as shown by the arrow, each rod 81 is inserted into the hole 7 and pushes up the poison rod 4, so that the poison rod 4 is The upper end portion protrudes according to the amount of protrusion of the rod 81, so that the poison rod 4 can be extracted from the upper part of the basket 1 using appropriate clamping means.

FIG. 4 shows another example of means for varying the amount of protrusion of the poison rod, in which the bottom plate 60 is formed so that the height of the bottom differs for each section. In this case, when the poison rod 4 is stored, the amount of protrusion of its upper end differs depending on the height of its bottom, so it can be easily removed for reprocessing. .

As explained above, this invention allows elongated radioactive waste to be efficiently stored in a basket, and also provides a means for adjusting the amount of protrusion at the bottom of the basket so that it can be easily extracted for reprocessing. This is what I did.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway perspective view of a basket showing an embodiment of this invention, Fig. 2 is a partial plan view of the basket showing another embodiment, Fig. 3 is a vertical sectional view of the lower part of the basket, and Fig. 4 is a FIG. 7 is a vertical cross-sectional view of the lower part of the basket showing another embodiment. 1... Basket, 3... Partition plate, 4... Poison stick, 5... Guide tube, 7... Hole, 8...
…Protruding means.

Claims (1)

[Scope of utility model registration request] It is a basket whose interior is divided into small compartments so as to store slender waste in close proximity to each other.The top of the basket is open, and each slender waste is inserted into each compartment one by one, and the basket is placed vertically. 1. A storage basket for radioactive waste, characterized in that the bottom of the basket is provided with means for differentiating the amount by which they project upward.