Thermal chemical treatment method for low-and-intermediate level radioactive waste

Abstract

The invention belongs to the technical field of low-and-intermediate level radioactive waste and relates to a thermal chemical treatment method for low-and-intermediate level radioactive waste for treating low-and-intermediate level radioactive organic combustible waste comprising radioactive substances generated by hospitals, scientific research institutions and nuclear power units, solving the problem of great deposit volume and difficulty of storage of the low-and-intermediate level radioactive waste, and achieving volume reduction and harmless treatment of the low-and-intermediate level radioactive waste. 0.1-1% of the purified radioactive substance smoke sucked by a power device is exhausted from a smoke air outlet, and 99-99.9% of radioactive elements are left in incombustible ash residues to be sealed uniformly and cured with cement, so that the processing course of the low-and-intermediate level radioactive combustible waste is finished. The volume reduction ratio of the low-and-intermediate level radioactive organic combustible waste reaches 97-99%. The method is reliable in principle, high in volume reduction ratio, good in curing effect, low in secondary pollution, friendly in application environment, low in investment and operation costs and energy-saving and environment-friendly, and has a good economical benefit and a wide market prospect.

Description

Technical field: [0001] The invention belongs to the technical field of medium and low radioactive waste treatment equipment, and relates to a waste treatment method, in particular to a thermochemical treatment method for medium and low radioactive waste, which is used for treating medium and low radioactive waste produced by hospitals, scientific research institutions and nuclear power units. Low-level organic combustible waste, to achieve volume reduction and harmless treatment of low- and medium-level radioactive waste. Background technique: [0002] From the technical level, radioactive waste is mainly divided into two categories: high radioactivity and medium and low radioactivity. High-level radioactive waste mainly includes spent fuel and its disposal products produced by nuclear fuel after power generation; medium and low-level radioactive waste generally includes nuclear power plant polluting equipment, testing equipment, hydration systems during operation, exchange...

AI Technical Summary

Problems solved by technology

However, due to the particularity of the components of low- and medium-level radioactive combustible wastes, a large amount of tar and soot will inevitably be produced during the combustion process of conventional general-purpose incinerators, making it difficult to meet the treatment standards.

In order to ensure complete combustion, the furnace needs to meet the necessary conditions such as high temperature, large air supply, long residence time and strong air flow disturbance, that is, the volume of the furnace is large enough to ensure sufficient combustion time. Therefore, the air supply in the furnace is greater than the theoretical amount , and the air excess coefficient is as high as 20 to 30 times. At the same time, in order to increase the turbulence of the combustion airflow, the furnace is often designed in various flow channel forms, and multiple post-combustion chambers are built after the combustion furnace and equipped with a large amount of auxiliary fuel. Increased energy consumption and pyrolysis products are easy to block the pipeline

Even so, it is difficult to ensure that the treatment of low- and medium-level radioactive combustible waste meets the standards

On the one hand, in the process of waste incineration, the content of tar and soot is still high; on the other hand, in order to ensure full combustion, the degree of disturbance of the airflow in the furnace needs to be large enough, and this will lead to more fly ash carried by the airflow, while A large number of non-volatile nuclides in the waste are attached to the fly ash, resulting in high radioactivity concentration in the flue gas, which increases the burden and difficulty of the flue gas post-treatment purification system; on the other hand, this kind of combustion furnace also has a limit on the calorific value of waste If the calorific value is too high or too low, the furnace temperature during the incineration process will be too high or vary greatly, which will cause damage to the refractory lining of the furnace. , not only is it difficult to automate, but also increases the risk of radiation exposure for operators

Therefore, the above-mentioned improvement of traditional incinerators still cannot fundamentally solve the problems existing in traditional incinerators

Obviously, traditional incinerators cannot meet the treatment requirements of low-medium level combustible waste, and the problem of radioactive combustible waste has still become a bottleneck restricting the rapid development of my country's nuclear industry. The volume reduction and harmless treatment of combustible waste is imminent

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