JPH0559399U - Radioactive material storage - Google Patents

Abstract

(57) [Summary] [Purpose] It is possible to clean the dust accumulated inside the intake pipe. An intake pipe line 22 for taking in cooling air into the cell chamber 1 is connected to a cooling air inlet shaft 23 for guiding cooling air downward from an intake port 21 and a lower side surface thereof to a lower side surface of the cell chamber 1. The cooling air inlet shaft 23 and the dust collecting chamber 2 are formed in an L-shape from the connection conduit 24, and a dust collecting chamber 25 is provided below the cooling air inlet shaft 23 so as to communicate therewith.
A radiation shielding door 28 that opens and closes between the two and communicates with and blocks the two 23 and 25 is provided. When the radiation shield door 28 is opened with dust 34 and the like accumulated, the dust 34 and the like fall into the dust collecting chamber 25, and then the radiation shield door 28 is closed to re-form the cleaned intake conduit 22. At the same time, the dust collection chamber 25 is shielded from the radiation so that the dust collection chamber 25 can be cleaned.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a storage for cooling radioactive substances such as radioactive waste by natural ventilation of cooling air.

[0002]

[Prior Art]

 Generally, radioactive waste such as high-level waste liquid generated in a nuclear power plant or the like can be improved in handleability by vitrification treatment, for example. Then, it is considered that the solidified body that has been treated by vitrification etc. is stored in the cell, but since the temperature rise due to the decay heat of the radioactive material during the storage, the solidified body and its supporting structure. It is necessary to cool things.

Conventionally, as a device for storing such a solidified product of radioactive waste, for example, as shown in FIG. 5, a ceiling plug slab 2 of a cell chamber 1 surrounded by a concrete wall can be sealed with a shielding plug 3. It is planned that the plurality of cylindrical containers 4 are suspended at intervals and the solidified bodies 5 are stored in the cylindrical containers 4 in a stacked state. In this case, since the solidified body 5 needs to be stored for a long period of time, the outer circumference of the cylindrical container 4 is surrounded by the outer cylinder 6, and a horizontal partition plate 7 surrounds the outer cylinder 6 to form the upper plenum 8 and the lower plenum. The cooling air taken in from the intake port 10 communicating with the atmosphere is guided to the lower part of the cell chamber 1 by the intake pipe 11 so that the ring shape between the cylindrical container 4 and the outer cylinder 6 is introduced from the lower plenum part 9. It is considered that cooling is performed by so-called natural ventilation by sending it into the cooling flow passage 12 and discharging it from the upper plenum portion 8 via the exhaust shaft 13.

[0004]

[Problems to be solved by the device]

 By the way, as the intake conduit 11, there is one in which the flow path is bent as shown in FIG. 5 in order to shield the radiation emitted from the radioactive substance inside the cell chamber 1. However, dust and the like are likely to be accumulated in the bent portion 14, and the vicinity of the bend portion 14 is not easily cleaned because it is exposed to radiation, so that the dust and the like is accumulated during long-term use. As a result, there is a problem that it becomes a resistance to natural ventilation.

The present invention has been made in view of such circumstances, and an object thereof is to make it possible to clean dust and the like accumulated inside the intake pipe line.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention stores a solidified body of radioactive material in a cell chamber surrounded by a radiation shielding wall, and cools the solidified body by cooling air taken from an intake port through an intake pipe line. In the storage compartment to be cooled, the intake pipe line connects the cooling air inlet shaft for guiding the cooling air downward, the lower portion of the cooling air inlet shaft and the lower portion of the cell chamber to each other, and the cooling air is introduced into the cell chamber from the side of the cell chamber. A radiation collection door which is composed of a connecting conduit for guiding the dust collection chamber, is provided below the cooling air inlet shaft, and is in a blocking state between the dust collection chamber and the cooling air inlet shaft. It is characterized by being opened and closed.

[0007]

[Action]

 In the storage of the present invention, the dust collecting chamber is provided under the cooling air inlet shaft so as to communicate therewith, and the radiation shielding door is provided between the cooling air inlet shaft and the dust collecting chamber. When closed, the cooling air is guided to the lower part of the cell chamber by the suction pipe line including the cooling air inlet shaft and the connecting pipe line. Then, when the radiation shielding door is opened, dust collected in the bent portion of the intake pipe is dropped into the dust collection chamber, and when the radiation shielding door is closed again, the intake pipe from which dust and the like has been removed. Along with the re-formation of the passage, the dust collection chamber is shielded and cleaning work can be performed inside the dust collection chamber.

[0008]

【Example】

 An embodiment of the storage of the present invention will be described below with reference to FIGS. This storage is also a storage of the solidified body of radioactive waste liquid, and the cylindrical container 4 which can be sealed from the ceiling slab 2 of the cell chamber 1 by the shielding plug 3 is hung and the respective cylindrical containers 4 are suspended. The cell chamber 1 is divided into an upper plenum portion 8 and a lower plenum portion 9 by the surrounding outer cylinder 6 and a horizontal partition plate 7, and the cooling air taken in from the intake port 21 through the intake pipe line 22 is tubular container 4 The structure in which the gas is discharged from the exhaust shaft 13 via the ring-shaped flow path 12 between the outer cylinder 6 and the outer cylinder 6 is the same as the conventional example shown in FIG. The intake pipe line 22 includes a cooling air inlet shaft 23 that guides cooling air downward, and a connecting pipe line 24 that connects the lower portion of the cooling air inlet shaft 23 and the lower portion of the cell chamber 1 to each other. It is a bent conduit to prevent radiation from the chamber 1 from leaking to the outside.

In the storage of this embodiment, the cooling air inlet shaft 23 is provided vertically to the side of the cell chamber 1 and has a rectangular horizontal cross section, and the connecting conduit 24 is The cooling air inlet shaft 23 is horizontally provided between the cell chamber 1 and the lower portion of the cooling air inlet shaft 23 to communicate with the lower portion of the cell chamber 1. Accordingly, the intake pipe line 22 is configured as an L-shaped pipe line that is bent at the connecting portion between the cooling air inlet shaft 23 and the connection pipe line 24. Below the cooling air inlet shaft 23, a dust collecting chamber 25 continuing to the outside is provided, and the dust collecting chamber 25 is cooled by a communicating portion 26 having a horizontal cross section similar to that of the cooling air inlet shaft 23. It is communicated with the inlet shaft 23. The dust collection chamber 25 is at least wider than the horizontal cross section of the communication portion 26, and is formed at a height such that a human can perform a cleaning operation inside. In FIG. 1, reference numeral 36 indicates an entrance for entering and exiting from the outside, and reference numeral 27 indicates a staircase.

A radiation shield door 28 is provided between the cooling air inlet shaft 23 and the dust collection chamber 25 to open and close in the horizontal direction to connect and block the two and 23. The radiation shielding door 28 is inserted into a storage recess 29 formed on the side surface of the communication portion 26, and is opened and closed by a drive mechanism 33 such as a motor 30 shown in FIG. 2, a rack 31, and a pinion gear 32. It is supposed to be done. Further, the radiation shielding door 28 is in close contact with the inner surface of the communicating portion 26 to completely shield the radiation to the dust collecting chamber 25, and forms the lower surface of the cooling air inlet shaft 23 to cool the cooling air inlet. The dust 34 and the like dropped through the mouth shaft 23 are accumulated on the upper surface 28a, and in the opened state, they are stored in the storage recess 29 as shown in FIG. Further, a triangular convex portion 35 is provided at a corner of the storage concave portion 29 near the upper surface 28a of the radiation shielding door 28, and the radiation shielding door 28 stored in the storage concave portion 29 has the upper surface 28a. It moves so as to slide along the convex portion 35.

In the storage configured as described above, when the radiation shielding door 28 is closed, the cooling air taken in through the intake port 21 receives the cooling air inlet shaft 23 and the connection conduit 24. It is introduced into the cell chamber 1 via 22 and cools the solidified body 5 in the cell chamber 1. When the dust 34 and the like enter the cooling air inlet shaft 23 together with the cooling air, they fall onto the upper surface 28a of the radiation shielding door 28 and accumulate as shown in FIG. 2 after a long period of time. When removing the accumulated dust 34, etc., the radiation shielding door 28 is opened as shown in FIG. 3, so that the dust 34 is scraped off by the convex portions 35 and swept into the dust collecting chamber 25. .. In this manner, after the dust 34 and the like on the upper surface 28a of the radioactive shielding door 28 are removed, the radiation shielding door 28 is closed again, so that the cleaned intake conduit 22 is re-assembled as shown in FIG. While being formed, the radiation from the cell chamber 1 to the dust collection chamber 25 is shielded.

Therefore, according to the storage of the present embodiment, even if dust 34 or the like is accumulated on the bent portion of the intake pipe line 22 during long-term storage, the radiation shield provided on the lower surface of the cooling air inlet shaft 23 is shielded. By opening and closing the door 28, the dust 34 and the like can be easily removed. Further, since the radiation shielding door 28 completely blocks the cooling air inlet shaft 23 and the dust collecting chamber 25, it is safe for humans in the dust collecting chamber 25 after the radiation shielding door 28 is closed. You can carry out cleaning work.

In this embodiment, the radiation shield door 28 is supposed to be opened and closed in the horizontal direction. However, in the closed state, the dust collection chamber 25 and the cooling air inlet shaft 23 are closed and opened to open the intake pipe line. As long as the dust 34 and the like in 22 are dropped into the dust collection chamber 25, for example, a single-opening type door or a double-door type door that opens downward may be used.

Further, the radiation shielding door 28 is adapted to open and close appropriately when dust 34 or the like is accumulated on the upper surface 28a to clean the inside of the intake pipe line. If it can be estimated, a timer or the like may be used to automatically open and close it periodically.

[0015]

[Effect of the device]

 As is clear from the above description, the radioactive substance storage device of the present invention has the following effects. (A) In the intake pipe, there is provided a radiation shielding door that opens and closes between the cooling air inlet shaft and a dust collecting chamber provided below the cooling air inlet shaft. Since it is swept up into the dust collection chamber by opening, the natural ventilation is not obstructed by dust and the like, and the storage can be maintained to function soundly even during long-term storage. (B) When the radiation shielding door is closed after the inside of the intake pipe is cleaned, the dust is completely shielded from the radiation in the dust collecting chamber, so that the cleaning operation in the dust collecting chamber can be performed safely.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an internal structure of a storage according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a state in which dust and the like are accumulated on the radiation shielding door of the storage in FIG.

FIG. 3 is a vertical cross-sectional view showing a state in which the radiation shielding door of FIG. 2 is open.

FIG. 4 is a vertical cross-sectional view showing a state in which the radiation shielding door of FIG. 3 is closed.

FIG. 5 is a vertical cross-sectional view showing the internal structure of a conventional radioactive substance storage.

[Explanation of symbols]

 1 Cell Chamber 4 Cylindrical Container 5 Solidified Body 8 Upper Plenum Part 9 Lower Plenum Part 13 Exhaust Shaft 21 Intake Port 22 Intake Pipeline 23 Cooling Air Inlet Shaft 24 Connection Pipeline 25 Dust Collection Chamber 28 Radiation Shielding Door 29 Storage Recess

Claims (1)

[Scope of utility model registration request] 1. A storage for storing a solidified body of radioactive material in a cell chamber surrounded by a radiation shielding wall, and cooling the solidified body by cooling air taken in through an intake pipe from an intake port, wherein the intake pipe Consists of a cooling air inlet shaft that guides cooling air downward, and a connection conduit that connects the cooling air inlet shaft lower part and the cell chamber lower part to guide cooling air into the cell chamber from the side of the cell chamber, A dust collecting chamber is provided below the cooling air inlet shaft, and a radiation shielding door for shutting off the dust collecting chamber and the cooling air inlet shaft is provided between the dust collecting chamber and the cooling air inlet shaft so as to be opened and closed. Characteristic radioactive material storage.