JPS60122397A - Volume decreasing treating method of radioactive waste - 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 method for purposefully reducing the volume of radioactive waste from facilities handling radioactive materials such as nuclear power plants.

Radioactive waste other than radioactive exhaust gas generated from nuclear facilities such as nuclear power plants includes radioactive liquid waste, combustible solid waste (e.g., combustible miscellaneous solids such as clothing, paper, and wood, activated carbon from air conditioning systems, and used ion exchange resin). , waste oil, etc.), and non-flammable solid waste (e.g. glass wool, metal parts, etc.)
etc.

Traditionally, radioactive waste? ! I Utilizing the burial and chemical properties, we perform volume reduction treatments such as concentration, drying, smoking, incineration, or compression, and then perform various solidification treatments such as asphalt solidification, cement solidification, etc. It is stored.

For example, in the case of radioactive waste liquid, the radioactive substances are separated and dried by chemical reaction to make them refractory, or the volume of volatile components is reduced by a collection section. Additionally, combustible solid waste is generally reduced in volume by incineration. For non-combustible solid waste, compression volume reduction is carried out.

Such treatment is carried out individually depending on the type of waste, and in each case, the aim is to improve volume reduction efficiency and stabilize the assimilate.

However, in order to stably solidify the products from the various volume reduction treatments mentioned above, various additives are added during assimilation to increase the volume, and the glass fibers of air filters discarded from air conditioning systems are nonflammable. However, due to the fact that the volume reduction efficiency of conventional compression treatment is not sufficient, the problem of waste storage is increasing year by year with conventional volume reduction treatment methods.
Immediate measures were required.

The present invention solves the above-mentioned problems and achieves efficient volume reduction,
The purpose of this invention is to provide a method for treating radioactive waste that yields a highly stable solidified material.

The Ministry of the Invention and others have identified products obtained by drying, smoking, incinerating, etc. waste liquid and combustible solid waste of radioactive waste (hereinafter referred to as incineration products) and radioactively contaminated waste glass.・
We came up with the idea of mixing fibers in an appropriate ratio and integrating them in a melting furnace to obtain a stable solidified product, and thus arrived at the present invention.

That is, the gist of the present invention is to provide products containing radioactive materials obtained by processing radioactive liquid waste and combustible solid waste generated from nuclear facilities by drying, smoking, incineration, etc. Waste glass with added
A method for reducing the volume of radioactive waste is characterized in that fibers are mixed in an appropriate ratio and heated and melted to form an integrated stable assimilate.

The present invention will be explained in detail below with reference to the drawings.

FIG. 1 shows the flow of one embodiment of the method of the present invention.

In FIG. 1, 1 is a melting furnace, 2 is an incineration product container,
2-1 is an incineration product cutting device, 2-2 is a cutting device 2-
1 setter, 3, 4, and 5 are containers for different types of waste glass fibers, and 5-1.4-1 and 5-1 are cutting parts for the waste glass fibers contained in the respective containers 5S5. , 6 is a device for collecting the melt discharged from the melting furnace.

The incineration product is an ash-like powder, while the waste glass fiber is a fibrous solidified material. As for the method of mixing these two in an appropriate ratio and feeding them into the melting furnace 1, an appropriate ratio can be obtained by changing either of them, but in this case, the amount of incineration products is calculated based on the amount of waste glass fiber. We will explain how to do this by changing the .

The components of waste glass fiber differ depending on the type of product, so it is better to collect and process products with the same components to obtain a more stable assimilated product. It is not limited to this and can be of any type.

Table 1 shows an example of the components of common incineration products.

Table 1 shows the components of the incineration products of the pressurized water reactor (PWR) and the incineration products of combustible miscellaneous solids in weight percent.

Table 1 Note that in order to reduce the volume of radioactive waste liquid, it becomes an aggregate mainly of various metal oxides containing radioactive substances that do not volatilize when burned. For example, in the case of a PWR power plant, Hou FRB is the main component, and in the case of a BWR power plant, Na is the main component.

Further, Table 2 shows an example of a typical E glass composition as a glass coolant composition.

In order to simplify the explanation of Table 2, the case where the waste glass fiber container 3 is used will be explained. First, a certain amount of waste glass fiber is introduced into the melting furnace 1 by the waste glass fiber cutting device 3-1. Next, the cut-out setting device 2 for the products of incineration, etc.
-2, the composition and amount of glass fiber in the waste glass fiber container 5 are mixed with an optimum amount of products such as incineration.

Both materials mixed into the melting furnace 1 are heated to a temperature at which the waste glass fibers are melted. In this case, among the various components attached to or contained in both, metals and metal oxides with a temperature higher than the melting point of the waste glass fiber exist in the solution as solid substances such as particles, but combustible substances are combustible. death,
A glassy product with the highest overall volume reduction is formed. In addition, when heated to a temperature that melts metals and metal oxides that are higher than the melting point of the fiber in the glass, the glass
The fibers and these metals and metal oxides are fused together and molecularly bonded to create a more stabilized glass-like product.

When the melting is finished, it is transferred from the melting furnace 1 to the melt collection container 6,
It is cooled to obtain an assimilate containing radioactivity, metals, metal oxides, etc. Alternatively, without transferring to the melt collection container 6,
It can also be taken out as an assimilate after being cooled and solidified in the melting furnace 1.

In the above method, the preferred mixing ratio of waste glass wool and incineration products is, for example, 2 in Table 1.
Mix 80% (W, T0%) of 0% glass wool and make approximately 1
, heated and melted at 400℃.

The composition of the obtained product was as follows.

sio□ B203A1203NIL20. CILO Others 46.9 18.7 11.6 0.9 14.8
7.1 This product is a solidified body of ordinary borosilicate glass, and has strength, stability, durability, and (note) oozing resistance at room temperature.

(Note) The exudation rate is expressed as the weight of the component exuded from a unit area when the product is forcibly stirred in distilled hot water at 100°C.

Also, as another example of a preferable mixing ratio, ■ is 20%
, ■ 25%, glass wool 31°2 B2O3 M'205 0aONa2O Others 49.8 16.4
8,0 10.2 o, 914.7 When this product was compared with the above product, y was at the same level and there were no differences in properties or other characteristics between people.

EXAMPLES Using the incineration products shown in Table 1 and the waste glass fibers whose compositions are shown in Table 2, volume reduction treatment was carried out according to the method of the present invention under the conditions shown in Table 3 below. The results obtained for each are also shown in Table 3.

The effects of the present invention are clear from the detailed explanation above, but the products of incineration are powders that easily scatter, are hygroscopic,
It is necessary to take such measures for storage and storage, and although there are methods for compressing and reducing the volume of waste glass fibers, the volume reduction efficiency is not the highest.However, the present invention solves these drawbacks at the same time. The leaching rate of radioactive materials is extremely low (it is possible to obtain a stable solidified material of sufficient quality in terms of strength and aging).It is an excellent volume reduction treatment method for radioactive waste.

[Brief explanation of drawings]

FIG. 1 shows a flowchart of an exemplary embodiment of the method of the present invention. Sub-agents 1) Clearance agent Ryo Hagiwara - Procedural amendment 1980/Month/2016 Director-General of the Japan Patent Office Kazuo Wakasugi 1, Indication of case Patent application No. 229091 of 1988 2 - Issue number 4' ) Unnamed Radioactive Waste Volume Reduction Processing Method 3, Relationship with the Amendment Case Patent Applicant Address 2-5-1 Marunouchi, Chiyoda-ku, Tokyo, 1″ (f, $4;) ( 620) Mitsubishi Heavy Industries, Ltd. 4, successor manager Address 16-2-5 Toranomon-chome, Minato-ku, Tokyo Date of amendment order Voluntary amendment (1) Column 8 of "Detailed Description of the Invention" of the specification, Amendment Contents (1) The statement ``Conventionally,'' on page 2, line 2 of the specification is corrected to ``Conventionally, intermediate and low-level radioactive waste is the same.'' (2) Between lines 6 and 4 on page 6, there are attempts to reduce the volume of high-level radioactive waste by vitrification, but high-quality glass frit is used as a material for glass. Moreover, it is necessary to select the glass and frit that is optimally formulated for each type of high-level waste, and conventionally high-quality glass and frit brought in from outside the nuclear facility was used, which was expensive. Moreover, there was a problem in that the amount of waste material clearly increased by the amount of glass frit that was brought in. ” is inserted. (3) On page 11, line 9, after the statement ``Can be obtained.'', there is a statement that says ``Glass is made of atomic materials.'' The material cost is zero because glass fiber is used, and there is no increase in waste, etc."

Claims (1)

[Claims] Products containing radioactive materials obtained by processing radioactive liquid waste and combustible solid waste generated from nuclear facilities by drying, collection, incineration, etc., and waste glass and fibers with radioactive materials attached are appropriately collected. A method for reducing the volume of radioactive waste, characterized by mixing the mixture at a suitable ratio and heating and melting it to form an integrated stable assimilate.