JPS59210400A - Method and box for storing radioactive waste - 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] This invention deals with radioactive waste, especially medium and low level radioactive waste.
1) It concerns a method for safely storing large quantities of things, and storage boxes used for storage.

Nuclear power plants generate various type 0 radioactive wastes, but in terms of quantity, most of them are medium- and low-level radioactive wastes with extremely high radioactivity levels. Conventionally, this medium- to low-level radioactive waste material was placed in drums and stored in a special storage facility within the nuclear power plant premises.

However, there is a limit to the durability of drums, and nuclear power plants produce a fixed amount of waste (3,000 to 5,000 drums per 00,000 kilowatts/year) from nuclear power plants every year. However, the space inside the buoy at the starting point 4 will be full at some point, so the above method cannot be said to be a permanent solution. Furthermore, stacking up a large number of drums, which are easily damaged, poses a safety problem in the event of a collapse or an earthquake.

As a countermeasure for this, as shown in Figure 1, several drums 8 (>i+'l are usually Book) Collection fH'+ 1. Attempts have been made to store concrete by filling the void in the storage box 1 with concrete and assimilating it by λfr. This method (d゛Concrete superior durability 1) (,
The cuboid box is much more stable than the cylindrical drum in terms of stability. However, even with this method, the dimensions of the box (130 to 160 cryr
, 90-120cm in height), the coffin is only 3-crotch.
However, there are still problems with the stability of the bar 11 stack during an earthquake.

Is it possible to improve the stability of the box by changing the dimensions from 4 to 6 to 9? Since the weight of a 9-pack is over 10 tons, it is difficult to improve the stability of the box after filling it with concrete. Regarding the handling weight of boxes and when pouring concrete; 111
Problems arise in both aspects of the rigidity of the board box, and there is a limit to how much stability can be improved by making the box larger.

This invention was designed to eliminate the drawbacks of the conventional methods as described above. A method that improves the stability of silk piles during stacking and storage, and makes it possible to safely store Inuso's medium and low-level radioactive waste within a narrow site, and a storage box used for Tore. It is intended to provide seven objectives.

That is, the first aspect of this invention is to store a container containing radioactive waste in a storage box made of precast concrete reinforced with reinforcing bars, and fill the void inside the storage box with mortar and solidify it. , the lower end of the tendon extending in the vertical direction is tied to the base anchor, the storage box filled with the mortar is penetrated through the tendon, and the concrete storage box is stacked one after another and the tendon is tensed. This is a method for storing radioactive waste, which is characterized by applying prestress to forming columnar bodies.

The second aspect of this invention is a storage box used in carrying out the above method, in which radioactive waste is stored in a block made of precast concrete IJ reinforced with reinforcing bars and having a shape that allows for the upper and lower sides to be separated. A hole is made to store the container, and a seat with a flat lower end is protruded from the bottom of the block.
It is characterized by having a through hole for tension insertion.

The invention will be described below with reference to examples 1j) and 3j) shown in the drawings.

First, regarding the storage box used in this invention method, N'1. Specifically, as shown in Fig. 2, the storage box 2 is made of a rectangular parallelepiped-shaped precast concrete block.
'4. There is a slight gap at the top and around the drum 8 when it is stored. There are also several 'r:1 holes 3 of sizes 1 and 81 in size, and the entire structure is reinforced with reinforcing bars. As shown in Figure 3, a seat 5 with a flat end surface is protruded from the bottom enclosure 4, and in this example, the seat 5 has a peripheral wall extending from the four edges of the bottom 4 to the chamber. If the 1111 error is set, (the IK is installed so that the storage box 2 is not acupuncture corrected),
A fork of a forklift (not shown) can be inserted into the space 11ii between the surface and the bottom surface 4. A through hole 6 for inserting a PC sliding rod, which will be described later, is formed in the seat portion 5 at the center of the hole 6, and the through hole 6 penetrates to the top of the storage box 2.

As shown in Fig. 4, the main part 5 is divided into several parts so that the moment of inertia around the through hole 6 in the ground plane becomes large, and the fork is inserted into the middle 1141. The shape may also be polygonal prism, cylinder, circle...) trapezoid. Furthermore, the storage 'jTj 2 may be packed in four drums as in the past, and the lid may be packed in six drums or more as shown in the fifth figure.

A method of storing radioactive waste using a storage box 2 such as a storage box 2 will be explained with reference to FIGS. 6 to 9.

As shown in Figs. 6 to 8, a drum can 8 containing radioactive waste 1 is stored in a straight storage hole 3 drilled in a storage box 2 made of precast concrete reinforced with reinforcing bars, and a blind hole is prepared in advance. A guide hole 7 for mortar injection provided on the side wall and bottom of 3.
Mortar 9 is injected into the hollow part of the blind hole 3 so that the soil part of the drum can 8 is poured and the top surface of the box 2 is flat, and the mortar 9 is filled and solidified. 10 is a recess provided on the top surface of the box 2, into which the seat 5 fits when the box 2 is placed 4;
We try to stop each other from wandering.

As shown in Fig. 9, the lower end of the rod J3 is tied by q% with the anchor 12, and this P C6j'l outer 13 Pass the pleasure storage 1τ box 2 through the through hole 6 to the storage box 2.
l1if+next 1ft, fij. After raising the storage box 2 by several 191 C, 1, l IT in this way, the concrete box 2 is tightened by a well-known means and the upper end of the PC rod 13 is secured to the concrete box 2 using a washer 14 and a nut 15. Fix it in the recess 25 prepared in advance on the base 18, and
C. A cement grout material is injected into the through hole 6 with a circumference of 4 g and 1 il, and a prestress is applied to the storage box 2 to form a columnar body 16 in which the storage box 2 is integrated.

Is the combination of further stacking storage box 2 PC Kozen 13 via Cupsy 17? ! -4 is added and the columnar body 16 is extended upward.

The columnar body 16, which is a masonry structure made in this way, often collapses or overturns even if lateral forces move, as in the proverbial earthquake, so it is difficult to use the conventional method of simply stacking. In comparison, a much larger number of stacks can be stacked safely. The vertical columnar body 16 can not only withstand lateral force but also support a large vertical load, and therefore the following storage method becomes possible.

In other words, as shown in the 2gto diagram, the columnar body 16 shaped as described above is placed vertically and horizontally on the foundation 11.
A part or all of these columnar bodies 16)'j1
! Roof 2 on [9] Steel frame tied to base 18 cast above
Join 2. Reference numeral 20 denotes a steel frame that supports the work floor for patrol inspections. By depositing a portion of the steel frame on the columnar body 16, lateral forces such as earthquake forces can be supported by the columnar body 16, so the steel frame 20 can only support vertical loads. It's okay to have something minor to support.

Studs 23 are erected on the steel frame 20 of the work floor, connected to the steel frame 19 of the roof, and walls 23 are connected to this. In this way, the roof 22 and walls 23 are supported by the columnar body 16, and a building 24 is constructed that extends over the entire columnar body 16. According to the method described above, it is possible to easily and inexpensively construct 44 buildings 24, which serve as storage rooms, without the need to construct long pillars from the ground while using the columnar bodies J6.

Combined with the durability of concrete, it is possible to safely and economically store a large amount of radioactive AI in a small area, making it possible to store red. A large amount can be stored in a small area, and if possible, the area for storage will be small, making it easier to inspect for abnormalities, and increasing the effectiveness of the floor fJj2.From this point of view, it is also economical and There are great locational benefits.

The conventional storage box 1 shown in FIG. 1 is equipped with a bottom plate r (type λ11 not shown) so that a fork of a forklift can be inserted between the storage box 1 and the bottom plate on the storage surface during transportation.
If each of the above-mentioned methods is carried out using such a storage box 1, when the Pc4.1 rod 13 is tensed, the shaped steel deforms and prestress cannot be effectively introduced. According to the storage box 2 of the present invention, the stress of the storage boxes 2 stacked vertically can be transmitted through the seat portion 5 protruding from the bottom surface 4, and when the storage boxes 2 are placed, Since a space is formed between the tube mounting surface and the bottom surface 4, it is possible to insert a fork and transport the tube.

In addition, compared to the method of this invention (l!: method of filling concrete into a steel box on site), the precast concrete storage box manufactured in Step 7 has excellent dimensional accuracy and high quality. Because of its strength, it can withstand pre-stress and its own weight better than storage boxes filled with cast-in-place concrete.
There is an advantage in being able to stand out if you know how tall it looks.

As described above, according to the present invention, a large amount of radioactive waste can be safely stored within a narrow site.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a conventional storage box, FIG. 2 is a perspective view of a storage box used in the method of the present invention, and FIG.
Figure 5 is a perspective view showing another example of a storage box; Figure 5 is a perspective view 5A showing an example of a storage box containing six drums; Figure 6 is a half-view of the box used in this invention; The figure is ■1-■ in Figure 6.
Figure 8 is the V'n of Figure 6!
Vertical section immersed in Ji Yes. 2... Storage Jf: + (: Box 3... Container storage hole 5... Seat 6... Through hole 8... Drum can 9... Filling mortar J1.
...Foundation 13...PC steel rod 16...Column body 6 sections hanging 7 flashes No 8 suspension 9 sections

Claims (1)

[Claims] ■ A container containing radioactive waste is housed in a precast concrete storage box reinforced with reinforcing bars, and the void inside the storage box is filled with mortar and solidified. The lower ends of the tendons extending in the vertical direction are tied together, a plurality of storage string boxes filled with the mortar and hardened are passed through the tension materials, and the storage boxes are stacked one after another. A method for storing radioactive waste (H), characterized by applying sore stress to the box to form a columnar body. 2. A box made of baskets and precast concrete that is reinforced with reinforcing bars and stacked on top of each other. It is characterized by having a hollow hole for storing a container containing radioactive waste, a protruding seat part on the side surface, and a through hole penetrating the top and bottom for holding the tension material. Storage box 8 used in the storage method according to claim 1