Preparation method of vitrification substrate for radioactive nuclear waste

Abstract

The invention relates to a preparation method of a vitrification substrate for radioactive nuclear wastes, which is characterized by comprising the following steps: mainly taking (NH4) H2PO4, Fe2O3 and H3BO3 as raw materials, proportioning, mixing, melting for 2-3.5 hours at the temperature of 1100-1250 DEG C, forming, and annealing, thereby preparing a vitrification body with glass of an iron-boron-phosphorus system as the substrate. The invention combines the advantages of high irradiation stability of the vitrification body of the borosilicate system and large waste-loading capacity of thevitrification body of the iron phosphate system. The prepared vitrification body has the advantages of excellent chemical stability and good thermal stability. Moreover, the invention has the advantages of simple preparation process and easy engineering, and can be widely applied in the curing treatment of radioactive nuclear wastes.

Description

A preparation method for radioactive nuclear waste vitrification substrate technical field The invention belongs to a method for treating radioactively polluted materials, and relates to a preparation method for vitrified substrates of radioactive nuclear wastes, which is suitable for the solidification treatment of radioactive nuclear wastes discharged in nuclear industry and other fields. Background technique As a highly efficient and clean energy with relatively mature technology, nuclear energy has positive and far-reaching significance for the country to adjust its energy structure, ensure energy security, promote energy conservation and emission reduction, and respond to climate change. The peaceful use of nuclear energy has a history of more than half a century. It has a profound impact on the improvement of people's living standards in my country and the world and the progress of science and technology. It has become an indispensable part of human progress. But the...

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Problems solved by technology

Borosilicate system glass has been widely used due to its low melting temperature, good chemical stability and radiation stability, but this system glass is harmful to waste "harmful impurities" (such as: phosphate, molybdate, sulfate , iron oxide and some other heavy metal oxides) have very poor solubility, causing the prepared solidified body to appear "yellow phase" and the performance cannot meet the requirements; in order to meet the performance requirements, the nuclear waste has to be pre-treated before solidification treatment. Treatment, or by prolonging the melting time, increasing the melting temperature, or reducing the content of such "impurities" in the solidified body at the expense of reducing the inclusion capacity, it is not advisable to increase the volume reduction ratio and reduce costs. of

The iron phosphate system glass has a good tolerance for such "impurities", and has the characteristics of good chemical stability, low melting temperature and large composition adjustability, so that the system glass has unique advantages as a solidified basic glass ; but the radiation stability and thermal stability of the iron phosphate system vitrified body are relatively poor compared to the borosilicate vitrified body, which limits its practical application

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