JPS5886500A - Method of storing in dry radioactive material - 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 provides spent nuclear fuel with high radioactivity and calorific value,
It relates to dry storage of radioactive materials, etc., which safely stores storage casks that house fission products or high-level vitrified solidified materials such as fRtl.

Conventionally, as one of the storage methods, spent nuclear fuel, fission products, or solidified high-level vitrification such as TRU at a nuclear power plant site, reprocessing facility, or storage facility weighs approximately 65 kg.
A method is known in which the cask is stored in a 140-ton class storage cask and placed in a building or other general area, and the heat generated from the cask is removed by drawing in outside air.

In other words, the plans for storing spent nuclear fuel or high-level vitrified materials in casks announced to date Fi
K 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 walls a on both sides of the building and exhausts it outdoors from the grill b on the ceiling.

However, the natural ventilation using the heat removal method described above is insufficient due to the structure of the reef house to remove heat evenly from the storage casks, and there are problems such as uneven heat removal effects, especially for storage casks that are heated to a medium temperature. was there.

This invention was made in view of the above-mentioned circumstances.
Or? In a facility that stores a large number of storage casks containing high-level vitrified solidified materials such as R[J, etc., storage Il! Introducing outside air to remove the heat generated from the middle yask.The outside air is introduced through the casks arranged near both sides of the outer walls of the ryokyo, and the outside air is introduced into the KFi above each cask except for the casks arranged in the center. do. A cover i is provided to prevent the above-mentioned outside air from flowing horizontally toward the central opening, and the outside air is discharged from the periphery of the cask placed in the center toward the ceiling. Each cask is designed to allow almost complete heat exchange with the outside air, and in particular contains radioactive materials intended to improve the heat removal effect of conventional storage casks, which were placed in the center and had poor heat exchange. This provides a dry storage method such as

Hereinafter, embodiments of the present invention will be described in detail based on 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 addition to the repair room 4, loading dock 5, etc., there is a trap changing room 6 to ensure the safety of workers, and an inspection room 7. A neuterity room 8 is provided.

In addition, a predetermined number of storage casks 10 are installed on both sides of Rikyo 1.
An outside air intake 11 for cooling is provided. Figures 41 and 5 are cross-sectional views along the mu line of Figure SG4 showing an embodiment of the present invention, and the ceiling 11iK in the building 1 is provided with a ceiling outlet 12 for exhaust air.

Further, ventilation ducts 13 are formed so that ventilation entering from outside air intake ports 11 provided on both side walls of the outhouse 1 is guided into the storage room 2.

In the storage room 2, a box-shaped rack 14 is fixed to the floor to prevent the casks from falling during an earthquake. is inserted and stands on its own.

Head part 10aKU of the storage cask 10 other than the central part, No. 65! l←)% (b) Information department 20. , the cap 2° with the edge 1s20bV is overturned, the guide 1120a is inserted into the frame 14a of the rack 14, and the edge 2ob is locked to the upper part of the frame 141 and arranged.

In addition, TI! J Medium 200&;r This is a small exhaust pipe provided at the center upper end of the cap 20, and functions as a 2° knob for the cap.

Therefore, in a storage method configured as described above.

The outside air led into the storage room 2 flows horizontally toward the center of the cask where the opening is, and is exhausted from the center to the outdoors through the ceiling outlet 12 while cooling each storage cask 10. .

Further, the knob/exhaust pipe 20° of the cap 20 is designed to prevent hot air from accumulating in the head 10aK of the storage cask 10. Furthermore, the number sequence of storage casks 10,
For example, if a partition plate is provided every 2 to 4 rows and partitioned into blocks every several rows, the amount of ventilation in each area can be made more uniform.

In addition, a traverse f15 is movably arranged on the ceiling of the ryokyo 1 via a rail 16v, and this )5/<-f1
5 will be installed and discussed. The above-mentioned traverser 15Kfl crane 17 is installed so that the storage cask 10 can be lifted up and moved to a predetermined position using a hanging odor 18.

On the other hand, i[Figure 7 shows another embodiment of the present invention, in which an outside air inlet 11 and a ventilation duct 13 are provided on both side walls of the villa 1.
In order to cool each cask 10, ventilation is provided in the vertical direction to each cask 1° through holes 21a provided in the duct 121.

That is, the duct 21 is installed on the upper surface of the floor of the storage room 2 and is communicated with the outside air intake port 11.
A hole 21° larger than the outer diameter of the cask 1G is formed at a predetermined location where the cask 1o is placed.
The cask 10 is inserted and fixed. Therefore, the outside air led from the outside air intake 11 through the duct 21v rises from the underfloor surface through the Jll enclosure of the cask 10, and
The outer periphery of o is uniformly cooled.

As explained in detail above, the IE method for dry storage of radioactive materials, etc. according to the present invention can be used in a facility with a simple building structure and a large number of storage casks.

By guiding outside air for heat removal through ducts and releasing it to the outside through the ceiling, each cask can be ventilated almost uniformly.
In particular, the heat removal effect of the cask placed in the center area is improved.

[Brief explanation of drawings]

1 and 2 are a vertical sectional view and an internal plan view of a villa showing a conventional embodiment, and FIGS. 3 and 4 are a perspective view and an internal plan view of a villa showing an embodiment according to the present invention. Figure 5 is a cross-sectional view of the Mu staff in Figure 4. FIG. 6(a) and @ are a perspective view and a cross-sectional view of a cap according to the present invention, and FIG. 7 is a cross-sectional view of a main part showing another embodiment according to the present invention. 1- Villa, 10- Storage cask, 11- Outside air intake, 12- Ceiling outlet. 13... Ventilation duct% 14... Rack, 2 G-
...Cap, 20. ---Guidance Department, 201) ---Frame. Patent Applicant Mitsubishi Metals Co., Ltd. Agent Hideaki Sato

Claims (1)

[Claims] Spent nuclear fuel with high radioactivity and calorific value, fission products, or? In a facility that stores a large number of storage casks that store high-level vitrified solidified materials such as RU, etc., the outside air to remove heat from the storage casks is introduced through outside air intakes installed on both sides of the building. Radioactive materials, etc. characterized by being led from i-casks arranged near both side walls through the casks, flowing horizontally to the casters, passing through the casks arranged near the center, and being discharged from the ceiling outlet. dry storage method.