JPS59173798A - Radioactive material storing container - 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] The present invention relates to a radioactive material storage container.

For example, methods for storing and transporting radioactive materials such as spent nuclear fuel with damaged fuel rod cladding include storing the radioactive materials in a storage container, storing the radioactive material storage container in a pool, or storing the radioactive material in a transportation container. They are stored inside and transported. The problem here is that
Due to the decay heat of the radioactive materials, the radioactive material-contaminated water in the storage container leaks out from the pressure regulating valve due to thermal expansion, contaminating the pool water and the water in the transportation container. Conventionally, it has been considered to provide a sintered metal filter at the discharge port of the pressure regulating valve, but this method not only does not remove radioactive materials sufficiently, but also requires the filter to be installed outside the radioactive material storage container. This can lead to valve blockage and external contamination due to solids. Furthermore, radioactive substances once removed by the filter may leak into the water or the water in the transport container due to impact on the storage container body, and handling is not easy from the standpoint of radiation protection.

Therefore, the present invention provides a radioactive material storage container that solves these problems, and is characterized by the fact that an ion exchanger is installed at the inlet of a pressure equalization valve disposed at an appropriate position in the radioactive material storage container. There is a VC that has set up a. According to this configuration, most of the radioactive substances contained in the radioactive contaminated water that is about to leak from the inside of the storage container to the outside through the pressure balancing valve are removed by ion exchange with the ion exchanger, and the radioactive substances are released from the pressure balancing valve to the outside. Water containing almost no radioactive materials is leaked into the tank. Furthermore, since the ion exchanger is provided within the storage container, radioactive substances are not allowed to leak out of the storage container. Therefore, contamination of pool water and water in transportation containers can be greatly reduced.

Hereinafter, one embodiment of the present invention will be described based on the drawings. In this embodiment, the radioactive material storage container (1) is connected to the transport container body (2).
), when transporting it by storing it in the inner cylinder (3) of (4).
) is the transport container lid, (5) is the main body (6) of the storage container (1)
A lid (8) is fixed to the upper opening of the
) is a pressure balancing valve disposed on the nuclear lid (5), and the lid (
5) is inserted into the through hole and welded to the cap (
9), a male coupler αQ screwed from above into a screw hole formed in the top plate portion of the cap (9), and a pressure balancing valve body (11) screwed into the screw hole from below,
It consists of an intermediate cylinder (6) whose upper male threaded part is screwed into the lower screw hole of the cap (9), and a holder (to) arranged at the bottom of the intermediate cylinder (2), and the holder (one and The intermediate cylinder (2) has a brown color formed on the suction port leading to the pressure balance valve body (6).In the case of α, it is an ion exchange device, and the upper part is a cylindrical part inserted into the suction port α. σQ and
An upper filter (17
1, an ion exchanger (goods) consisting of an ion exchange resin, an inorganic ion/exchanger, activated carbon, etc. arranged in the center of the cylindrical part qQ, and an ion exchanger (goods) arranged on the lower surface of the ion exchanger (g). lower filter (11) and a ring-shaped screw (E) that is screwed into the lower end screw hole of the cylindrical part QQ to support the lower filter θ value.
It is composed of. The holder (B) includes a cylindrical holder body 3υ whose upper end female threaded portion is screwed into the lower male threaded portion of the intermediate cylinder (2), and holder bodies formed at appropriate intervals in the circumferential direction at the lower part of the holder body υ. A plurality of ball wires that are inserted into the through hole and fitted into an annular groove formed at an appropriate location on the outer peripheral surface of the cylindrical portion aei of the ion exchange device Qυ inserted into the suction port α, and a holder body. A female coupler that is slidably fitted onto (c) and also backs up each of the balls @ and presses each ball @ into the annular groove (a).
And, the female coupler (goods) and the holder body G! η) and a stopper ring for preventing the female coupler from coming off, which is fixed to the lower end of the holder body (B).

(To) is the O-ring, (Goods) is the fuel assembly, (C) is the hanging tool, and the handle is the Loveture disk.

The operation of the above configuration will be explained. While being transported as shown in Figure 1, when the radioactive material-contaminated water in the storage container is heated by the decay heat of the radioactive material, it thermally expands.
Part of the contaminated water passes through the ion exchanger (to) and leaks into the transport container body (2) from the suction port a4 through the pressure balance valve body aυ. Most of the radioactive substances contained in the contaminated water are removed by ion exchange with the ion exchanger (e) when passing through the body (g), and the radioactive substances are removed from the pressure balance valve (8) to the transport container body (2).
Water that contains almost no radioactive materials is leaked inside.

Next, when replacing the ion exchanger ←, use the bolts (7
) and remove the lid (5), then remove the female turnip 2-(c)
and slide it in the direction of arrow (A). As a result, the backup of the pole holder by the female cover (c) is released, and the fitted state between the ball holder and the annular groove (2) is released. Next, by grasping and pulling the ion exchanger aυ, you can easily remove this ion exchanger (1i19) from the suction port a<.Next, insert the tip of the new ion exchanger (c) into the suction port U.
When inserted into the ball, the ball) fits into the annular groove (4), completing the installation of the ion exchanger (g).

In the above implementation row, the case where the storage container (1) is stored and transported inside the transportation container body (2) was explained as an example, but it can also be applied to the case where the storage container (1) is submerged in a pool. In this case, it prevents contamination of pool water.

As described above, according to the present invention, 1. Most of the radioactive substances contained in the radioactive substance-contaminated water that is about to leak from the storage container to the outside through the pressure balance valve are removed by ion exchange with the ion exchanger, and the pressure Water containing almost no radioactive substances is leaked from the balance valve to the outside. Furthermore, since the ion exchanger is provided within the storage container, radioactive substances are not allowed to leak out of the storage container. Therefore, there is very little contamination of pool water or water in transport containers.

[Brief explanation of drawings]

The figures show one embodiment of the present invention, in which Fig. 1 is a longitudinal sectional view of a transport container, Fig. 2 is a partially cutaway front view of a radioactive material storage container, Fig. 3 is a plan view of the same container, and Fig. 4 is a longitudinal sectional view of a transport container. The figure is a longitudinal sectional view of the main part. (1)...Radioactive material storage container, (2)...Transportation container body, (8)...Pressure balance valve, qη...Pressure balance valve body, a3...Holder, Q4)...・Inhalation port, q
υ...Ion exchange device, (g)...Ion exchange agent Yoshihiro MorimotoFigure 1Figure 3Figure 2

Claims (1)

[Claims] 1. A radiation source characterized in that an ion exchanger is disposed at the inlet of a pressure balance valve disposed at an appropriate position in a radioactive substance storage container. substance storage container.