JPH0749440Y2 - Storage of radioactive waste - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a storage facility for radioactive waste, and particularly to improve the soundness of a solidified package of high-level radioactive waste during storage and storage.

“Conventional technology and its problems” Generally, high-level radioactive waste generated in a nuclear power plant, for example, is treated by vitrification,
The handleability can be improved. The so-called solidified package that has undergone treatment such as vitrification is stored in the storage cell for a long period of time, but since the temperature rise and thermal expansion due to the decay heat of the radioactive material accompany the storage, the inside of the cell chamber There is a plan to send air into the room to cool it.

In this case, it is necessary to solve the following problems in order to store the solidified package for a long period of time and prevent contamination of the surrounding environment.

(I) Storage for a long period of time without exerting an external force on the solidified package.

(Ii) Prevent radiation leakage during storage.

(Iii) Continuous cooling during storage of the solidified package.

(Iv) To simplify the building structure.

An object of the present invention is to solve such problems and to secure soundness during storage period, prevent radiation leakage, improve handleability, simplify the structure, and the like.

"Means for solving the problem" As a means for solving the above problems, in a storage for storing a stored object in which a solidified package is stored in a cooling channel formed along a vertical direction in a concrete block, A support slab that is arranged in the lower part of the cell chamber of a storage building that stores a plurality of stored objects and that mounts the stored objects in a vertically stacked state; and a cooling flow path of the stored object that is formed in a penetrating state in the supporting slab. The radioactive waste storage has a structure including a suction hole communicating with the cell chamber and an upper exhaust port formed in the upper part of the cell chamber for discharging heated air.

[Operation] The weight of the stored items stacked vertically is supported by the part of the concrete block, and no external force is applied to the solidified package in the cooling channel. The radiation shielding effect of the layer significantly reduces the amount of leakage to the outside.

If the temperature of the solidified package rises due to heat generation,
Convection occurs in the cooling channel of the concrete block, the low temperature air is sucked from the suction hole of the support slab to cool the solidified package, the cooling air is heated and discharged from the upper exhaust port of the cell chamber to the outside. To be done.

In this case, when the stored objects are in the vertically stacked state, the cooling air is guided by vertically connecting the cooling flow paths to cool the stored objects.

[Embodiment] An embodiment of the radioactive waste storage according to the present invention will be described below with reference to FIGS. 1 to 4.

In the figure, symbol X is a stored object, C is a concrete block, P
Is a solidification package obtained by subjecting high-level radioactive waste to vitrification, etc., 1 is a storage building for storing a large number of stored objects X, 2 is a cell chamber, 3 is formed above the cell chamber 2. The upper exhaust port, 4 is a support slab arranged below the cell chamber 2 for loading the stored objects X in a vertically stacked state, 5 is a suction hole formed in the support slab 4 in a penetrating state, and 6 is a concrete block C. It is a cooling channel formed in the up-down direction inside.

An outside air intake 7 for taking in outside air as cooling air is provided on the side wall portion of the storage building 1, and a cooling air introduction duct 8 and a horizontal induction duct 9 are connected to the outside air intake 7 so as to be horizontal. Support slab 4 on the induction duct 9
The suction holes 5 are communicated with each other. An overhead crane 10 for suspending the concrete block C is installed above the cell chamber 2.

A plurality of vertical ribs 11 for supporting the supporting slab 4 are provided in the lower portion of the supporting slab 4, and the horizontal guiding duct 9 is divided into a plurality of parallel ribs by the vertical ribs 11 as shown in FIG. , Are connected to the cooling air introducing duct 8, respectively.

Next, the details of the stored object X will be described. The concrete block C is, as shown in FIGS. 3 and 4,
It has a substantially regular hexagonal shape, and hooks 12 for hanging are provided symmetrically on the upper part of the side surface, and as shown in FIG. 4, seven cooling flow paths 6 are opened in the central part. Channel 6
As shown in FIG. 3, the solidified package P has a support frame.
It is supported by 13 so as to be in the upper and lower center position and with a gap formed between it and the hole wall of the cooling flow passage 6, and the screw ducts 14 of the cooling flow passage 6 are provided above and below the solidified package P. It is attached so as to occlude a part.

That is, as shown in FIG. 4, an annular gap is formed around the solidified package P, and the support frame 13 is formed in a grid pattern or a grid pattern so that the cooling air flows in the vertical direction. The outer circumference of the screw duct 14 is formed as a male screw surface, so that a spiral gap is formed between the cooling duct 6 and the hole wall surface of the cooling flow channel 6, and the cooling flow channel 6 is vertically moved as a whole. It is in the inserted state.

As shown in FIG. 2, such a stored object X is combined in a honeycomb shape, and the cooling sluices 6 are arranged on the suction holes 5, and as shown in FIG. 4 is stored in a multi-tiered state.

Then, in the cell room 2 of the storage building 1, the overhead crane 9 and the hook portion 12 are used to suspend and transport the stored object X,
When the objects to be stored X are stacked and stored in a multi-tiered state, decay heat of the radioactive material is generated according to the amount of the solidified package P stored.

Due to this heat generation, the air around the solidified package P is heated, and the heated air becomes an upward flow, passing through the spiral gap between the surface of the screw duct 14 and the wall surface of the hole of the cooling passage 6. Then, as shown by each arrow in FIG. 1, the cell chamber 2 is further raised from the cooling flow path 6 and is discharged into the atmosphere from the upper exhaust port 3.

Then, the cooling flow path 6 becomes a reduced pressure atmosphere,
Cooling air in a low temperature state is taken in through the outside air intake port 7, and then, through the cooling air introducing duct 8 and the horizontal guiding duct 9, from the suction holes 5 into the respective cooling flow paths 6, thereby cooling the solidified package P and the solidified package P. Heat is exchanged with air, and solidification package P is formed by natural convection of cooling air.
Is sequentially cooled.

Further, the solidified package P portion thermally expands in the vertical direction and the like due to the temperature rise due to its own heat generation. However, as shown in FIG. 3, the solidified package P is mounted on the support frame 13, Since the thermal expansion in the upward and outward radial directions is free, the thermal expansion and contraction of the solidified package P does not affect the concrete block C and the like.

On the other hand, most of the radiation emitted from the solidified package P collides with the concrete block layer due to the presence of the concrete block C around the solidified package P, is attenuated and absorbed, and is stored. The leakage radiation dose emitted out of X can be very small.

Further, the vertical radiation along the cooling flow path 6 is attenuated by colliding with the screw duct 14.
In this case, the radiation passing through the spiral gap formed between the surface of the screw duct 14 and the hole wall surface of the cooling flow path 6 has a small attenuation amount, but the screw duct 14 has a large specific gravity. By forming it from steel or the like, it is possible to secure the necessary amount of attenuation.

"Effect of the Invention" As described above, the radioactive waste storage according to the present invention has the following excellent effects.

Since the objects to be stored are stacked vertically on the supporting slab in the lower part of the cell chamber and the objects to be stored contain the solidified package in the cooling channel of the concrete block, the solidified package is protected by the concrete block. Therefore, external force is not applied to the solidified package, and the solidified package can be stored in a stable state for a long period of time to improve the soundness.

Since the solidified package is surrounded by the concrete block and the radiation is absorbed and attenuated by passing through the concrete block layer, it is possible to significantly reduce the radiation leakage to the outside of the cell room and improve the handleability of the stored object. it can.

Cooling air is sent from the suction port of the support slab to the cooling channel of the concrete block, and natural convection is discharged from the upper exhaust port of the cell chamber.Therefore, cooling of the solidified package during storage is continuously stable. Can be done.

When the stored items are mounted on a support slab and are stacked vertically, the cooling channels are in communication with each other to facilitate cooling, and radiation leakage is prevented as described above.
The building structure can be simplified and simplified.

[Brief description of drawings]

1 to 4 show an embodiment of a radioactive waste storage according to the present invention. FIG. 1 is a front sectional view, FIG. 2 is a view taken along the line II-II in FIG. FIG. 3 is a front sectional view of the radioactive waste stored, and FIG. 4 is a view taken along the line IV-IV of FIG. X: Stored object, C: Concrete block, P ...
Solidified package, 1 ... Storage building, 2 ... Cell room, 3 ...
… Upper exhaust port, 4… Support slab, 5… Suction hole, 6…
… Cooling channel, 7 …… Outside air intake, 8 …… Cooling air introduction duct, 9 …… Horizontal induction duct, 10 …… Overhead crane, 11 …… Vertical rib, 12 …… Hook part, 13 …… Support frame ,14
...... Screw duct.

Claims (1)

[Scope of utility model registration request] 1. A storage compartment for storing a stored object in which a solidified package is stored in a cooling channel formed in a concrete block along a vertical direction, and a lower part of a cell chamber of a storage building for storing a plurality of stored objects. A support slab that is mounted on the support slab to mount the stored objects in a vertically stacked state, a suction hole that is formed in the support slab in a penetrating state and communicates with the cooling flow path of the stored object, and is formed in an upper portion of the cell chamber. A storage facility for radioactive waste, comprising: an upper exhaust port for discharging heated air.