Method for solidifying radioactive nuclide fission product cesium by perovskite structure oxide

Abstract

The invention discloses a method for solidifying radioactive nuclide fission product cesium by perovskite structure oxide. The method comprises the steps that Ba(NO3)2, CsNO3 and Zr(NO3)2.5H2O are taken and added into water for stirring, and a chelating agent is added into the stirred solution for stirring; after a gel is added into the stirred chelated solution for stirring, the temperature is risen slowly until sol becomes gel; the gel is dried, then is placed in a resistance furnace for pre-sintering and is taken out, and after grinding is carried out, a black powder precursor is obtained;the black powder precursor is taken for heat treatment, a nano-powder sample is prepared, the nano powder sample is pressed into blocks, pressure maintaining is carried out, calcination is carried out, and a solidified body is prepared. According to the method for solidifying the radioactive nuclide fission product cesium by the perovskite structure oxide, the perovskite structure oxide with highself-adjusting capability and capable of containing a wide range of elements is adopted as a solidified parent structure, low-temperature phase formation is carried out by a Sol-Ge method, a pressed block sintering process is combined, and low-temperature solidification of Cs is realized by preparing the solidified body; and after Cs is solidified by adopting the solidified matrix structure, the stability is high, and the leaching rate is low.

Description

technical field [0001] The invention relates to the technical field of solidification of radionuclide fission products, in particular to a method for solidifying radionuclide fission product cesium by using a perovskite structure oxide. Background technique [0002] At present, with the development and utilization of nuclear energy and the rapid development of nuclear technology, the problem of radioactive pollution is becoming more and more prominent. in, 137 Cs is one of the most important heat sources of radionuclide fission products in high-level liquid waste, and is also the main source of radioactivity. It is extremely dangerous and can emit β particles and strong γ rays. This element has strong migration and diffusion in the environment, and it is very easy to enter the human body through the biological chain and cause cancer, which poses a great threat to human health. Currently, radionuclides and nuclide fission products 137 The industrial treatment method of Cs ...

AI Technical Summary

Problems solved by technology

For example, in the prior art, phosphate is used as the substrate to cure Cs, but the higher heat treatment temperature and time will lead to the volatilization of Cs

In the prior art, the solid solution amount of Cs in Ba-type xerolite was also studied, and it was found that the highest chemical overcapacity of Cs in single-phase xerolite was only 0.26 mol, and excessive Cs would generate heterogeneous phases

However, there is no report on the solidification of Cs by using perovskite structure oxides.

In addition, the preparation method of ceramic solidified materials is mainly a high-temperature solid-phase reaction method. The process is to contact the solid-phase reactants with each other, and prepare the target through the process of contact surface and phase region diffusion, migration, crystal nucleus formation and nucleus growth. Products, the general synthesis temperature is high (~1400-1500 ℃), the preparation time is long (>48h), and the heterogeneous phase is easily formed during the synthesis process, and the higher phase formation or sintering temperature will cause the volatilization of Cs elements and cannot achieve Solidification purpose

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