JPS6240680B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to a method for filling and sealing containers for disposing of radioactive waste liquid, and improvements to the apparatus. Radioactive liquid discharged from nuclear power plants is concentrated in concentrators (evaporators, reverse osmosis devices, etc.) and then solidified. One of the solidification treatment methods is a vacuum injection method using cement. This is a method of solidifying concentrated waste liquid by filling a drum with vermiyukiyurai cement, evacuating the entire drum, and allowing the concentrated liquid to soak into it. A void as shown in FIG. 1 is created in the upper part of the drum and in the vacuum injection cage. Therefore, when disposing of the drum, it is necessary to fill the void with a filler or the like (this operation is called capping). Conventionally, this method involves opening the lid of the drum and applying mortar (see Figure 2), but this method has the following drawbacks. In FIGS. 1 and 2, a represents a container, b represents a void, c represents mortar, and d represents a solidified cement body. (i) Since it is necessary to open the lid of the drum, there is a risk of external contamination due to radioactivity. (ii) Because it is not possible to fill the cage with mortar sufficiently, the strength of the drum cannot be increased. (iii) Since the capping operation is manual,
There is a risk that workers may be exposed to radiation, so a capping method using remote control is desired. There were some problems (defects) such as: The present invention was proposed with the aim of providing a method and apparatus capable of eliminating the drawbacks of the conventional methods described above. Radioactive waste liquid is placed in a container sealed with cement and kept in a vacuum. This relates to a method for filling and sealing a container for disposing of radioactive waste liquid, which is characterized in that, in enclosing and solidifying, after injecting the radioactive waste liquid, an expandable fluid mortar is press-fitted into the container while rotating the container, It also includes a rotary table to which a container is detachably attached, a mortar transfer pipe detachably connected to the injection port of the container, a mortar transfer pump connected to the pipe, and a mortar supply device connected to the pump. The present invention relates to a filling and sealing device for a container for disposing of radioactive waste liquid, which is characterized by comprising: Hereinafter, an example of an apparatus for carrying out the method of the present invention shown in FIG. 3 will be specifically described. In the figure, reference numeral 1 denotes a mortar transfer pump, and the pump 1 uses a mortar supply device (not shown) to continuously supply mortar to its hopper portion through a mortar pushing screw 10 driven and rotated by a drive source M. The inside of the radioactive waste liquid disposal container 11 is supplied via the mortar transfer pipe 2 and the introduction pipe 3, which have one end connected to the discharge port of the mortar transfer pump 1 and the other end connected to the mortar injection conduit 3. It is adapted to be inserted into a vacuum injection cage 6.
4 is a vacuum injection hole provided in the sealed top lid 12 of the container 11 as shown in the figure, 5 is a vacuum injection conduit, 7 is a cement solidified body, and 8 is a rotating table (turntable), the rotating table is not shown in the figure. The drive source rotates the container 2 around its axis within a predetermined rotational speed range (60 to 120 rpm), and the rotary table 8 allows the container 2 to be detachably attached. It is configured to be easy to install. In addition, 9 in the figure indicates a mortar for injection, and the mortar 9
Use a mortar that has been mixed in advance with a mortar mixer, but if the mixing ratio is shown in the attached table in Figure 4, the flow value of the mortar is 22 to 27 seconds, and the expansion rate is
3.5 to 6%, and the breathing rate is about 2 to 3%, resulting in an expandable fluid mortar. When injecting the expandable fluid mortar into the cavity in the container 11 [vacuum injection cage 6 and other cavities (see Figures 1 and 2)] using the mortar transfer pump 1, the table below shows As shown in , the flow value should be 30 seconds or less, and the grain size of the sand used should be 2.5φ or less. Furthermore, in order to inject the mortar into every corner of the cavity, an expansion agent is mixed into the mortar so that it expands when solidified, and the appropriate expansion rate is about 5 to 10%. In addition, if the breathing rate is too large, voids will occur when the mortar solidifies, so it must be kept at 3% or less.

[Table] Next, experimental examples of the present invention will be explained. The mortar transfer pump 1 is operated, and the injection mortar 9 having the above-mentioned mixing ratio is passed through the mortar transfer pipe 2 and the mortar injection conduit 3 into the vacuum injection cage 6 (void portion) of the cement solidified body 7 in the container 11. At the same time, the rotary table 8
was rotated around its axis at rotational speeds ranging from 60 to 120 rpm. As a result, the mortar for injection 9 was filled to every corner of the cavity of the container 11, especially the upper circumferential portion of the container 11. In this case, the mortar injection conduit 3 has an inner diameter of 13φ and an outer diameter of 13φ, taking into consideration the diameter of the vacuum injection hole 4 of the upper lid 12 of the container 11, the inner diameter of the vacuum injection conduit 5 of 27φ, and the fluidity of the injection mortar 9. A copper pipe with a diameter of 15φ was used. In summary, the present invention is characterized in that cement is encapsulated,
Radioactive waste liquid is sealed and solidified in a container whose interior is kept in a vacuum, and after injecting the radioactive waste liquid, an expandable fluid mortar is pressurized into the container while rotating the container. Since the gist of the present invention is a method for filling and sealing a disposal container, the present invention provides: (1) Capping operations can be performed remotely without opening the top lid of a radioactive waste liquid disposal container; Damage caused by external contamination and exposure to radioactivity can be reduced. (2) Since the mortar for injection can be filled and sealed to every corner of the cavity of the container 11 by the centrifugal action of the rotary table 8, the solidified cement can be completely capped. The following practical effects can be mentioned. The present invention also provides a rotary table to which a container is removably attached, a mortar transfer pipe removably connected to the injection port of the container, a mortar transfer pump connected to the pipe, and a mortar transfer pump connected to the pump. Since the gist of the present invention is a filling and sealing device for a radioactive waste liquid disposal container, which is characterized by being equipped with a mortar supply device, the method of the present invention described above can be carried out reliably.

[Brief explanation of the drawing]

1 and 2 are schematic explanatory diagrams of a conventional method, respectively, and FIG. 3 is a schematic explanatory diagram of an example of an apparatus for carrying out the method of the present invention. In Fig. 3, 1: Mortar transfer pump;
2: Mortar transfer piping, 8: Rotary table,
9: mortar, 11: container filled with cement and kept in vacuum.

Claims (1)

[Scope of Claims] 1. When enclosing and solidifying a radioactive waste liquid in a container filled with cement and kept in a vacuum, after injecting the radioactive waste liquid, the expandable fluid mortar is poured into the container while rotating the container. A method for filling and sealing a container for radioactive waste disposal, characterized by press-fitting the container into the container. 2. A rotary table to which a container is removably attached;
A radioactive waste liquid disposal container comprising: a mortar transfer pipe detachably connected to the injection port of the container, a mortar transfer pump connected to the pipe, and a mortar supply device connected to the pump. filling and sealing equipment.