JPH0528558Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to an apparatus for storing solidified packages of radioactive waste materials while cooling them.

"Prior Art and Problems" In general, high-level radioactive waste generated in nuclear power plants can be made easier to handle by, for example, being vitrified into a vitrified package of a predetermined shape. It is considered that the solidified package that has been subjected to a treatment such as vitrification is housed and stored in a storage device. Furthermore, the storage equipment used for this purpose not only does not leak radiation, but also prevents the temperature rise of the solidification package and its storage equipment due to decay heat generated from the radioactive materials being stored. Consideration must be taken to suppress this.

As the storage device, an outer tube is provided in a radioactive waste storage chamber provided below the concrete slab, and an inner tube is further provided within the outer tube, and the solidified packages are stored in a stacked manner within the inner tube. Storage methods are being considered. Also,
In this storage system, the decay heat generated from the solidified package within the inner tube is removed by circulating cooling air through the space between the inner and outer tubes.

By the way, in the above-mentioned storage device, if radioactive material were to leak from the inner tube, the radioactive material could spread throughout the cooling air circulation system, so external forces caused by earthquakes or changes over time may cause It is desirable to perform regular maintenance and inspection to ensure that the airtightness is not compromised due to

However, since the work of inspecting the inner tube fixed within the outer tube is carried out in the radioactive environment of a radioactive waste storage room, the time required for inspection is shortened as much as possible to minimize the amount of radiation exposure for workers. Therefore, it is necessary to improve workability.

This idea was proposed in view of the above circumstances.
The purpose of this invention is to facilitate maintenance and inspection of the inner tube that houses the solidified package, and to open and close the cooling flow path regardless of whether or not the solidified package is housed.

``Means for Solving the Problems'' In order to achieve the above object, the present invention provides an outer tube that is open at the top and bottom and is placed below the insertion hole that vertically passes through the upper slab of the radioactive waste storage chamber. and,
An inner tube is inserted into the outer tube so as to be movable up and down and accommodates radioactive waste, and an inner tube is disposed between the insertion hole and the inner tube to suspend the inner tube and to adjust the horizontal rotation position of the inner tube. support means disposed near the lower ends of the inner tube or the outer tube, the air flow passageway between the inner tube and the outer tube when the inner tube is moved to the lower position; This radioactive waste material storage device is equipped with an opening/closing means for opening the radioactive waste material storage device.

"Operation" By employing such means, the inner tube is supported by the support means and can be inserted into and removed from the outer tube, and inspections and the like can be carried out by pulling out the inner tube.

When the inner pipe is suspended in an upper position by the support means, the opening/closing means closes the air flow passage, and when the inner pipe is suspended in a lower position by the support means, the opening/closing means closes the air flow passage. The flow path is now open. Therefore, the air flow passage can be opened and closed regardless of whether or not the solidified package is stored.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 3 show an embodiment of the present invention, and reference numeral 1 in the figures indicates an upper floor slab of a storage facility. A radioactive material storage chamber 2 is provided below this upper floor slab 1.
An outer tube 3 having a space in which an inner tube to be described later is accommodated is vertically supported by a support structure 4. Furthermore, a passage 6 for circulating cooling air is provided between the support structure 4 and the lower floor slab 5 below it. Further, the upper floor slab 1 is provided with an insertion hole passing through it vertically, and an upper outer pipe 7 is embedded in the insertion hole so as to have the same axis as the outer pipe 3. The upper outer tube 7 functions to support the inner tube 8 that accommodates the solidified package P, and together with the outer tube 3 constitutes a storage space for the inner tube 8.

A plurality of support protrusions 9 are provided on the upper outer periphery of the inner tube 8.
are provided facing outward in the radial direction, and these support protrusions 9 are placed on a support portion 10 provided on the upper inner periphery of the upper outer tube 7 to support the inner tube 8 in a predetermined position. I'm starting to do that. Furthermore, a guide groove 11 is formed on the inner periphery of the support portion 10 . This guide groove 11 has a width slightly larger than the circumferential dimension (thickness) of the support protrusion 9, and the guide groove 11 has a width slightly larger than the circumferential dimension (thickness) of the support protrusion 9.
The inner tube 8 is guided to the lowered position shown in the figure. The upper outer tube 7, the support protrusion 9, the support part 10, and the guide groove 11 constitute a support means X for supporting the inner tube 8 in a suspended state, as shown in FIG. 3 and the like.

On the other hand, an opening/closing plate 12 is provided at the lower end of the inner tube 8 . This opening/closing plate 12 has an external dimension slightly smaller than the lower opening 13 of the outer tube 3, and closes the lower opening 13 when the inner tube 8 is in the raised position as shown in FIG. Further, as shown in FIG. 2, when the inner tube 8 is lowered, it is seated on the lower floor slab 5 to support the load of the inner tube 8. These opening/closing plates 12 and lower opening 1
3, as shown in FIGS. 1 and 2,
An opening/closing means Y is constructed.

Note that 14 is a plug that closes the upper opening of the inner tube 8, 15 is a hanging piece used when lifting the upper tube 8, and 16 is a lid that closes the upper opening of the upper outer tube 7.

In the storage device configured as described above, if the solidification package P is not housed in the inner tube 8, there is no need to supply cooling air to the inner tube 8, so the inner tube 8 is configured as shown in FIG. Support protrusion 9 of tube 8
By shifting the positions of the guide groove 11 of the support part 10 in the circumferential direction, the support protrusion 9 is formed on the support part 10.
As shown in the figure, the inner tube 8 can be placed in a position where the opening/closing plate 12 closes the lower opening 13. By stopping the supply of cooling air to such an empty inner tube 8, the cooling air can be used effectively. On the other hand, solidified package P
is accommodated, rotate the inner tube 8 to align the support protrusion 9 and the guide groove 11 in the circumferential direction, and while sliding the support protrusion 9 along the guide groove 11, as shown in FIG. As shown in FIG. 3, the opening/closing plate 12 may be lowered until it is seated on the lower slab 5 to guide cooling air into the outer tube 3. Further, when maintenance and inspection are required, the inner tube 8 can be lifted upward and removed from the outer tube 3 to carry out predetermined work in a place other than the radioactive waste material storage room, for example.

Further, FIGS. 4 and 5 show other embodiments of the present invention. In this embodiment, the cooling air is prevented from flowing to the outer tube 3 which has become empty after the inner tube 8 has been removed. A support pedestal 17 is provided on which the opening/closing plate 12 at the lower end of the opening/closing plate 8 is placed. The support frame 14 has a diameter that can fit into the lower opening 13, and
It is supported so as to be movable in the vertical direction by an elastic member 18 such as a spring. These lower opening 13, support pedestal 17, and elastic member 18 also constitute an opening/closing means Y, as shown in FIGS. 4 and 5.

When the inner tube 8 is accommodated, the support frame 17 can move downward while contracting the elastic material 18 to open the opening 13, as shown in FIG. . Furthermore, as shown in FIG.
rises and the load is no longer applied to the support pedestal 17, so the resilient material 18 returns and the support pedestal 17 rises, sealing the opening 13 and stopping the inflow of cooling air into the outer tube 3. I can do it. In this embodiment, cooling air does not flow into the outer tube 3 which has become empty after the inner tube 8 has been removed.
It is possible to prevent an imbalance in the flow of cooling air in the storage room due to the extraction of air.

Note that the opening/closing means Y is not limited to the above-mentioned embodiments, and other means capable of opening and closing operations in conjunction with insertion and removal of the inner tube may be applied.

"Effects of the invention" The radioactive waste material storage device according to the invention has the following effects.

Since the inner tube is inserted into the outer tube in a suspended state by the support means so as to be movable up and down, maintenance and inspection of the inner tube can be easily performed by pulling the inner tube upward. There is.

changing the horizontal rotational position of the inner tube and suspending the inner tube at an upper position and a lower position by means of a support means;
Since the air flow passage is opened and closed by the opening and closing means, the cooling flow passage can be opened and closed regardless of whether or not the solidification package is stored.

[Brief explanation of drawings]

Figures 1 to 3 show an embodiment of the present invention, in which Figure 1 is a vertical cross-sectional view of the inner tube in the raised state, Figure 2 is a vertical cross-sectional view of the inner pipe in the lowered state, and Figure 3 is a vertical cross-sectional view of the inner pipe in the lowered state. A perspective view of the engaging portion between the tube and the upper outer tube, FIGS. 4 and 5 show other embodiments of the present invention, and FIG. 4 is a longitudinal cross-sectional view of the inner tube in the lowered state;
FIG. 5 is a longitudinal sectional view in a state where the inner tube is removed. 1... Upper floor slab, 2... Radioactive material storage room, 3... Outer pipe, 6... Passage, 7... Upper outer pipe,
8...Inner tube, 9...Support protrusion, 10...Support part,
11... Guide groove, 12... Opening/closing plate, 13... Lower opening, 17... Support pedestal, 18... Resilient material, 19
...Hanging tool, P...Solidified package, X...Supporting means, Y...Opening/closing means.

Claims (1)

[Scope of utility model registration request] 1. A radioactive waste storage device comprising: an outer pipe 3 open at the top and bottom and disposed below an insertion hole penetrating an upper floor slab 1 of a radioactive waste storage chamber 2; an inner pipe 8 inserted into the outer pipe so as to be movable up and down and for containing radioactive waste; support means X disposed between the insertion hole and the inner pipe for suspending the inner pipe and for positioning the inner pipe at an upper or lower position depending on the horizontal rotation position of the inner pipe; and opening and closing means Y disposed near the lower end of the inner pipe or the outer pipe for opening an air flow passage between the inner pipe and the outer pipe when the inner pipe is moved to the lower position.