JP3029213B2 - Radioactive waste treatment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating radioactive waste by effectively utilizing fine powder generated by crushing concrete in nuclear facilities.

[0002]

BACKGROUND OF THE INVENTION Peaceful use of nuclear energy in Japan has been in use for more than thirty years, and is now receiving worldwide attention. And there is nuclear power as one of the peaceful uses of nuclear power,
Today, nuclear power plays an important role as a stable power supply. By the way, just as every object has a life, a nuclear power plant cannot avoid its life. If this is a normal facility, the treatment after dismantling of the facility will not be so problematic, but the disposal and dismantling of the dismantled waste from the facilities at the nuclear power plant will need to be studied in the future, including economics.

[0003] It is estimated that hundreds of thousands of tons of waste are generated when dismantling nuclear power plant facilities. At present, disposal of large amounts of waste to general disposal sites is considered to be a problem in the future due to the location of general industrial waste disposal sites. Is economically problematic, and it is required to reuse demolition waste.

[0004]

DISCLOSURE OF THE INVENTION By the way, of the hundreds of thousands of tons of waste generated by dismantling nuclear power plant facilities, 90%
The remainder is believed to be concrete and reinforced waste.
Moreover, it is estimated that most of the concrete has a low radioactivity level of less than 10 ^-4 curie / ton. It is considered that such low-level waste does not need to be carried into the radioactive waste disposal site, but a more rational disposal method is expected.

[0005] In Japan, the basic policy of the country is to dismantle the facilities of a nuclear power plant that has reached the end of its life and use the site. That is, dismantling the facilities of a nuclear power plant does not mean that nuclear power is unnecessary, but it is necessary to construct a new nuclear power plant along with the dismantling. The construction of this nuclear power plant requires a large amount of concrete materials.

[0006] Accordingly, if concrete waste from a nuclear power plant generated by demolition of concrete having a low radioactivity level or substantially free from pollution problems as described above can be effectively used for construction of a new nuclear power plant,
It is thought that the waste of resources can be eliminated, the use can be performed with higher safety, and the cost of dismantling can be reduced. From this viewpoint, concrete waste from nuclear power plants Has been proposed by the applicant of the present invention to crush crushed material into a construction material (aggregate) for a nuclear power plant.

[0007] When producing aggregate by crushing waste concrete, a large amount of fine powder is produced. And, the treatment of this large amount of fine powder must also be made effective. At the same time, it must be taken into account that this is from nuclear facilities. The present invention has been made in view of the above, and an object of the present invention is to provide a technique for effectively utilizing waste materials generated by dismantling nuclear facilities and reducing processing costs. It is.

[0008] The object of the present invention arises when producing aggregate by crushing concrete in nuclear facilities.
Fine powder that cannot be used as construction material is sorted out.
This is achieved by a radioactive waste treatment method characterized by filling the obtained fine powder into a radioactive waste treatment container containing miscellaneous solids. Also, construction materials generated when aggregate is produced by crushing concrete at nuclear facilities
Fine powder that cannot be used as
This is achieved by a radioactive waste treatment method, which comprises filling a powder and a solidifying material into a radioactive waste treatment container containing miscellaneous solids.

[0009]

[0010] That is, according to the present invention, a radioactive waste treatment container containing fine solids generated by the crushing of concrete at a nuclear-related facility, as well as inorganic solidified materials such as cement and water glass, containing miscellaneous solids. The fine powder generated when crushing concrete at nuclear facilities and producing aggregate by filling in the space or filling the gap between radioactive waste treatment containers located at the radioactive waste disposal site It can be effectively used for the disposal of radioactive waste, and such use will not cause any problems even if the concrete is contaminated by radioactive materials, and the disposal will be highly safe. Further, no special disposal as radioactive waste is required, and the processing cost is reduced accordingly.

The present invention will be described in more detail. Although various things are generated as waste from nuclear facilities, aggregate can be composed of waste generated by dismantling concrete of nuclear facilities.
In order to obtain aggregate from concrete waste generated by the demolition of concrete at nuclear facilities, coarse splitting is performed as a first step using a hydraulic breaker, etc.
Crushing is performed to about m square. After that, as a second step, the earth and sand adhered to the concrete block is removed by grizzly, and in the third step, the concrete block is divided into small pieces by a jaw crusher or the like, and the reinforcing steel and the concrete are separated. In the next fourth step, the rebar separated by the magnetic separator is removed. After the rebar is removed by the magnetic separator, the primary crushing by an impact crusher is performed as a fifth step. That is, the concrete mass conveyed by the belt conveyor is crushed by the impact crusher, and the screen has a particle size of about 0 to 10 mm, 10 to 40 mm.
Of about 40mm and more than 40mm
The above grains are returned to the impact crusher again,
A grain of 10 mm and a grain of 10 to 40 mm are obtained. As a sixth step, the grains having a size of about 10 to 40 mm obtained in the primary crushing step are sent to a coarse aggregate regenerating machine where they are processed and sieved with a screen to obtain a regenerated coarse aggregate. As a seventh step, the granules of about 0 to 10 mm obtained in the primary crushing step are sent to a fine aggregate regenerating machine, processed and sieved by a screen, and the regenerated fine aggregate, fine sand, fine powder ( Sludge) is obtained.

By the way, the applicant of the present invention proposes that the thus obtained recycled coarse aggregate, recycled fine aggregate and fine sand are used as construction materials for nuclear facilities. Fine powder is difficult to use as construction material for nuclear facilities. However, this fine powder is filled in the radioactive waste treatment container containing miscellaneous solids, or in the gap between the radioactive waste treatment containers located in the radioactive waste disposal site, that is, when disposing of radioactive waste. I realized that it could be used as a filler. In other words, until now, miscellaneous solids have simply been placed in a radioactive waste disposal container, but by filling with the fine powder as described above and solidifying it, the safety is further improved. If there is a concern that the fine powder itself may be contaminated with radioactive materials, there is no problem since this will be transported to a radioactive waste disposal site. Also, filling the fine powder as described above in the gap between the radioactive waste disposal containers arranged in the radioactive waste disposal site,
It is expected that the solidification will further increase the safety, and there is no problem even if the fine powder itself is concerned about contamination by radioactive substances.

[0013] A radioactive waste disposal container or SFPIC container (high soundness container of Chichibu Cement Co., Ltd.) containing miscellaneous solids is filled, or a radioactive waste disposal container disposed at a radioactive waste disposal site is disposed. In order to fill the gap, only fine powder may be used, but ordinary Portland cement, early strength Portland cement, ultra-high strength Portland cement, medium heat Portland cement, sulfate resistant Portland cement, blast furnace cement, silica cement, fly ash cement, In addition, it is preferable to use a cement-based solidifying material for soil containing a large amount of SO ₃ component.

[0014]

Example 1 Instead of concrete at a nuclear facility, a kneaded product of fine powder and Solfix 12 (a cement-based solidified material of Chichibu Cement Co., Ltd.) generated by the crushing of concrete in a building dismantlement was used as a simulated real waste. The solid was filled into a radioactive waste disposal container.

According to such a treatment, miscellaneous solids are solidified in the radioactive waste treatment container.
Expected to be more secure.

[0016]

[0017]

[0018]

According to the present invention, concrete concrete for nuclear facilities
Construction materials generated when aggregate is produced by crushing
Fine powder that cannot be used as
It is expected that the powder will fill the voids in the radioactive waste disposal container, so that the safety will be higher, and the fine powder used for this will be generated during the production of aggregates by crushing concrete at nuclear facilities. Monodea is, tooth
Since Ru der that can not be used as a duck construction materials, and be free of waste, it just whether waste can be effectively utilized, processing cost of waste becomes cheap, and even by the crushing of the concrete of the nuclear-related facilities Even if the generated fine powder is concerned about radioactive contamination,
This has no problem and has features such as high safety.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Naoaki Koyanagi 2-1-1, Tsukimi-cho, Kumagaya-shi, Saitama Chichibu-Cement Co., Ltd. Central Research Laboratory (72) Inventor Hiroaki Kato Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa No. 8 Toshiba Corporation Yokohama Office (72) Inventor Masato Oura 3-1-1 Sachimachi, Hitachi-shi, Ibaraki Hitachi, Ltd. Hitachi Plant (56) References JP-A-64-20499 (JP, A) JP-A-2-44297 (JP, A) JP-A-3-81700 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G21F 9/30 G21F 9/36 G21F 9/34

Claims (2)

(57) [Claims] Use as construction material generated when aggregate is produced by crushing concrete at nuclear facilities
A method for treating radioactive waste, characterized in that fine powder that cannot be separated is sorted and the sorted fine powder is filled in a radioactive waste treatment container containing miscellaneous solids. 2. Use as construction material generated when aggregate is produced by crushing concrete at nuclear facilities.
A method for treating radioactive waste , comprising selecting an unrecognizable fine powder and filling the selected fine powder and solidified material into a radioactive waste treatment container containing miscellaneous solids.