Method for analyzing trace plutonium content in large amount of uranium in nuclear fuel aftertreatment process

Abstract

The invention belongs to the technical field of analytical chemistry, and relates to a method for analyzing trace plutonium content in a large amount of uranium in a nuclear fuel aftertreatment process. The analysis method sequentially comprises the following steps: (1) taking a sample with a certain volume, and adding concentrated nitric acid to adjust the concentration of nitric acid to 1-2 mol / L; (2) adding a sodium nitrite solution into the sample, uniformly mixing and standing for a period of time; (3) adding an extraction agent into the sample for extraction, performing centrifugal separation, removing a water phase, and retaining an organic phase; (4) washing the organic phase with a washing solution for 2-5 times, removing the water phase after each washing, and retaining the organic phase; and (5) diluting the organic phase with isopropanol, and analyzing the diluted organic phase with ICP-MS provided with an organic sample injection system. By utilizing the method for analyzing the trace plutonium content in the large amount of uranium in the nuclear fuel post-treatment process, the trace plutonium content in the large amount of uranium in the nuclear fuel post-treatmentprocess can be simply, conveniently, quickly and accurately analyzed with less required sample amount and little interference.

Description

technical field [0001] The invention belongs to the technical field of analytical chemistry and relates to a method for analyzing trace plutonium content in a large amount of uranium in a nuclear fuel reprocessing process. Background technique [0002] Nuclear fuel reprocessing has very strict requirements on the control of plutonium in uranium products. In the uranium product of the reprocessing process, the concentration of uranium is tens of grams per liter, and the ratio of uranium to plutonium exceeds 1×10 9 , a large amount of uranium to a trace amount 239 Pu analysis is very disturbing. To accurately measure the concentration of plutonium in the sample solution, it is necessary to undergo a strict pretreatment process for the separation of uranium and plutonium, so that uranium and plutonium can be separated. Therefore, a good pretreatment process for the separation of uranium and plutonium is the key to the accuracy of the analytical data. However, there are many ...

AI Technical Summary

Problems solved by technology

The pretreatment process of the separation of uranium and plutonium in this method includes adsorption, rinsing, elution and other processes, the process is complicated, and the pretreatment of a single sample takes 2-4 hours; the sample consumption is large, requiring 5-50ml; the sample with low plutonium concentration , in the process of adsorption, leaching and elution of ion exchange, some plutonium will be lost, resulting in low analysis results (see: Li Lili, Li Jinying, Zhao Yonggang, etc. Separation of trace plutonium in uranium matrix[J]. Nuclear Chemistry and Radiation Chemistry, 2007,29(3):135-140.)

[0006] Therefore, the above methods have the disadvantages of large analysis error, large sampling volume, complicated separation process and long operation time when analyzing nuclear fuel reprocessing process samples.