JPS6025496A - Method of treating 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 [Kimikari] relates to a method for treating radioactive waste generated from nuclear power plants (BWR) and the like.

Conventional methods for disposing of radioactive waste include solidifying it with cementite, solidifying it with picumen, and converting it into 1M plastic.

These processing methods, taking concentrated tM'd as an example, e, '
By adding cement, ditumene, plastic, etc. to the ld1M solution and kneading the mixture, radioactive waste is incorporated into the mixture. However, according to these treatment methods, a mixture is added to radioactive waste that has not been reduced in volume and solidified, resulting in a considerable increase in volume after assimilation. In addition, Na25O4 (sodium sulfate), which is the main component of the concentrated waste liquid, is present in the solidified material with QτJ■
Even if it is incorporated, it remains in the form of a salt, which poses problems such as being easily eluted into water. Furthermore, according to the conventional method,
Separate equipment is used to dry, incinerate, and assimilate radioactive waste, such as concentrated liquid waste, combustible solid waste, waste resin, and sludge, making the process time-consuming.

The purpose of the present invention is to solve the problem of conventional waste disposal, and the radioactive waste generated from nuclear power plants, etc. is charged into a Karasu electric melting furnace, and the radioactive waste described in 1a is processed by the melting glass of the J5 electric melting furnace. This objective is achieved by providing a method for disposing of radioactive waste, which comprises drying and incinerating the substance, melting it in the molten glass, and pouring the molten 1fi glass containing the radioactive substance into a container and solidifying it. As a result, the volume of the solidified body can be reduced and Na2S is added to the solidified body.
It is possible to prevent O4 from existing in the form of salt, and it is also possible to perform drying, incineration and assimilation treatments all at once.

The method of the present invention will be explained in detail below based on the drawings showing one embodiment thereof.

In the figure, (1) is a glass electric melting furnace used in the method of the present invention. (2) is the incineration melting chamber of this electric glass melting furnace (1), and (3) is the fining chamber installed adjacent to the incineration melting chamber (2) VC.
The third tunnel is separated by a weir (4), allowing only the lower part to communicate. (5) is a pair of electrodes installed through the bottom wall of the incineration melting chamber (2) and the fining chamber (3).
) The function is to generate Joule heat inside the glass (6) that has been scratched across the compartments of the glass (6) to melt the glass (6). (7) is an air supply pipe that penetrates the bottom wall of the incineration melting chamber (2) and has a large number of openings in the bottom curve of the incineration melting chamber, and is made of a heat-resistant and corrosion-resistant alloy such as Inconel. The function is to supply air into the incineration melting chamber (2) to promote the melting reaction. (8) is a resistance heating wire installed through the ceiling wall of the fining chamber (3), and is made to protrude into the chamber without touching the nochorus (6) in the fining chamber (3). ) in the glass (6) 'f
-It functions to heat. In the figure, (9) is the radioactive waste inlet installed on the upper side wall of the incineration melting chamber (2), 01 is the exhaust gas outlet installed on the ceiling wall of the incineration melting chamber (2), and 0υ is the clarification chamber. (3) is a sprue provided on the side wall.

Next, a method for disposing of radioactive waste will be explained step by step using the glass electric melting furnace (1) having such a configuration.

First, heat the heat over an open flame such as gas or electric heat.
After heating the Harasu to around 00°C, alternating current is applied to the electrode (5). Then, a current flows between the electrodes 4i and (5), and Joule heat is generated inside the crow (6). Due to this heat generation, the glass (6) is then continuously melted. At this time, the melting temperature of glass (6) is 1200 to 15
It is about 00℃.

Next, radioactive waste (for example, concentrated waste liquid, sludge) is introduced into the incineration melting chamber (2) through the input port (9).

At this time, if you want to pour in the concentrated waste liquid, use a glass (
Add 5xOz (silica oxide) ingredients such as clay to adjust the ingredients in step 6). In addition, when a large amount of combustible solid waste is to be input, J5 lath galette is added to adjust the composition of the lath (6).

The injected radioactive waste is heated and dried by molten glass (6) in the incineration melting chamber (2), and is combusted by air supplied from the air supply pipe (7). This will reduce the volume of radioactive waste. In addition, the supplied air not only stirs the molten glass (6) and promotes the melting reaction (particularly mixes well with the ash), but also
It is preheated by the molten glass (6) to provide good drying and combustion air. So2 generated by combustion etc. Exhaust gases such as CO2 are discharged from the exhaust gas outlet uQ and processed in the v1 treatment facility.

The dry salt and incineration ash of the radioactive waste dried and burned in this way are sufficient for the molten glass (6).
I do it. Then, the molten glass (6) containing this radioactive material will flow through the Vi weir (4) and into the purity chamber (3).

Next, in the clarification chamber (3), the molten glass (6) containing the radioactive substance is made homogeneous and any remaining air bubbles are removed. The clarified molten glass (6) is then poured into a prepared container through a sprue 9 and cooled to form a solidified glass. The obtained vitrified material has excellent water solubility, heat resistance, and fire resistance, and is stable during long-term storage.

Therefore, according to the method of the present invention, radioactive waste is dried and incinerated to reduce its volume and then melted into molten glass.
The volume of the solidified body can be reduced and the presence of NaB5O4 in the form of salt in the solidified body can be prevented. In addition, since we use a 73 ras 'commercial air melting furnace, drying,
Incineration and solidification can be performed all at once, and there is little risk of scattering radioactive materials. Furthermore, since the obtained solidified material is a nolas solidified material, it has excellent water solubility, heat resistance, and fire resistance, and is stable during long-term storage, making it optimal as a solidified material for radioactive waste.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view showing an example of a glass electric melting furnace used in the method of the present invention. (1)...jff lath electric melting furnace, (6)...13
Las (molten glass) Agent Yoshihiro Kiyoshi

Claims (1)

[Claims] (2) Radioactive waste generated from nuclear power plants, cities, etc. is put into an electric glass melting furnace, and the radioactive waste is dried and incinerated by the melting glass of the gas melting furnace, and the radioactive waste is melted into the molten glass. A method for disposing of radioactive waste characterized by pouring molten glass containing radioactive substances into a container and solidifying it.