JPS6139640B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention safely stores a storage cask containing high-level vitrified solidified materials such as spent nuclear fuel, fission products, or TRU, which have high radioactivity and calorific value. Concerning dry storage methods for radioactive materials, etc.

Conventionally, high-level vitrification, which solidifies spent nuclear fuel, fission products, TRU, etc. at a nuclear power plant site, reprocessing facility, or storage facility, has been used as a storage method in storage casks weighing approximately 65 to 140 tons. A known method is to place the cask in a facility such as a building housed in a cask, and draw in outside air to remove the amount of heat generated from the cask.

In other words, the plans for storing spent nuclear fuel or high-level vitrified materials in casks that have been announced so far are as shown in Figures 1 and 2.
The amount of heat generated from the storage cask is removed by natural ventilation, which takes in outside air from the side walls a on both sides of the building and exhausts it outdoors through the grill b on the ceiling.

However, due to the structure of the building, the natural ventilation using the heat removal method described above is insufficient to remove heat evenly from the storage casks, and in particular, the heat removal effect of storage casks placed in the middle may be uneven. There was a problem.

This invention was made in view of the above-mentioned circumstances.
To remove the heat generated from the storage casks in a flat storage facility where a large number of storage casks containing high-level vitrified solidified materials such as nuclear fission products or TRU are placed vertically and stored in one tier. Outside air is guided from the introduction duct toward the casks arranged near both side walls of the building, and a cover is installed above each cask to prevent the introduced outside air from rising, except for the casks arranged in the center. The structure is configured so that outside air flows horizontally toward the central opening, and is released from around the cask located in the center toward the ceiling. A device that enables heat exchange, and provides a dry storage method for radioactive materials, etc., with the aim of increasing the heat removal effect of conventional storage casks, which are placed in the center and have poor heat exchange. It is.

Embodiments of the present invention will be described in detail below with reference to FIGS. 3 to 7. 3 and 4 are a perspective view and an internal plan view of a facility for storing a large number of storage casks 10 according to the present invention. In the figures, a storage room 2 is arranged in a building 1, and a control room is adjacent 3. Repair room 4. Loading dock 5
In addition to the above, a changing room 6, an examination room 7, and a utility room 8 are provided to ensure the safety of workers.

Furthermore, outside air intake ports 11 are provided on both side walls of the building 1 to cool a predetermined number of storage casks 10.

FIG. 5 is a sectional view taken along the line A--A in FIG. 4 showing one embodiment of the present invention, in which a ceiling outlet 12 for exhaust air is provided in the ceiling of the building 1.

In addition, outside air intakes 11 installed on both side walls of building 1
A ventilation duct 13 is formed so that the ventilation entering from the storage room 2 is guided into the storage room 2.

In the storage room 2, racks 14 forming a box shape to prevent casks from falling during an earthquake are fixed to the floor surface, and storage casks 10 are inserted into each frame 14a of each box-shaped rack 14. and independent.

The head portion 10a of the storage cask 10 other than the central portion has a cap 2 provided with a guide portion 20a and an edge portion 20b as shown in FIGS. 6A and 6B.
0 is overturned and the guide part 20a is easily
is inserted into the frame 14a of the frame 1, and the edge 20b is inserted into the frame 14a.
It is arranged to be locked to the upper part of 4a.

In addition, in the figure, 20c is a minute exhaust pipe provided at the upper center end of the cap 20.
It functions as a 0 knob.

Therefore, in the storage method configured as described above, the outside air introduced into the storage chamber 2 flows horizontally toward the center of the cask where the opening is, cooling each storage cask 10 while cooling the center. The air is exhausted from the ceiling through the ceiling exhaust port 12 to the outdoors.

In addition, the knob of the cap 20 and the exhaust pipe 20
c is designed to prevent hot air from remaining in the head 10a of the storage cask 10. Further, by providing a partition plate every several rows of storage casks 10, for example every 2 to 4 rows, and dividing the storage casks 10 into blocks, the amount of ventilation in each area can be made more uniform.

In addition, there is a traverser 15 on the ceiling of the above building 1.
is movably arranged via rails 16 and installed on this traverser 15. A crane 17 is installed on the traverser 15, and the storage cask 10 can be lifted up and moved to a predetermined position using a lifting device 18.

On the other hand, FIG. 7 shows another embodiment according to the present invention, in which each cask 10 is cooled from an outside air intake 11 provided on both side walls of the building 1 and a ventilation duct 13 through a hole 21a provided in a duct 21. each cask 1
The structure is such that ventilation is carried out in the vertical direction.

That is, a duct 21 is installed on the upper floor of the storage room 2 and communicated with the outside air intake port 11, and a hole 21 larger than the outer diameter of the cask 10 is provided at a predetermined location of the duct 21 where the cask 10 is placed.
a is formed, and the cask 10 is inserted and fixed into this hole 21a. Therefore, the outside air introduced from the outside air intake port 11 through the duct 21 rises from the underfloor surface through the periphery of the cask 10, and uniformly cools the outer periphery of the cask 10.

As explained in detail above, the dry storage method for radioactive materials, etc. according to the present invention has a simple building structure, and in facilities that store a large number of storage casks, outside air for heat removal is led through ducts and By discharging the heat to the outdoors, each cask is exposed to ventilation almost uniformly, and the heat removal effect of the cask placed in the center is particularly improved.

[Brief explanation of the drawing]

Figures 1 and 2 are a vertical sectional view and an internal plan view of a building showing a conventional example, and Figures 3 and 4 are
The figures are a perspective view and an internal plan view of a building showing an embodiment of the invention, FIG. 5 is a sectional view taken along the line A-A in FIG. 4, and FIGS. 7 are sectional views of essential parts showing other embodiments of the present invention. 1...Building house, 10...Storage cask, 11...
Outside air intake, 12... Ceiling outlet, 13... Ventilation duct, 14... Rack, 20... Cap, 2
0a...Guidance section, 20b...Frame.

Claims (1)

[Claims] 1. A flat storage facility in which a large number of storage casks are vertically placed to store spent nuclear fuel, fission products, or high-level vitrified solidified materials such as TRU, which have high radioactivity and calorific value, and are stored in one tier. In this method, outside air for removing heat from the storage casks is guided from outside air intakes provided on both side walls of the building through an introduction duct toward the casks arranged near both side walls, and the casks arranged in the center are guided. A cover is installed above each cask to prevent the introduced outside air from rising, and the introduced outside air is flowed horizontally toward the central opening, passed through the casks arranged near the center, and then released from the ceiling outlet. A dry storage method for radioactive materials, etc., characterized by: