Method for cycle purification of uranium in Purex process

Abstract

The invention discloses a method for cycle purification of uranium in a Purex process. The method comprises the following steps of: pretreating 1CU feed liquor, seasoning, and further purifying plutonium by using a washing agent in a two-dimensional (2D) tank, wherein the used washing agent in the 2D tank is a mixed solution of dimethyl hydroxylamine, monomethyl hydrazine and nitric acid, the concentration of the dimethyl hydroxylamine is 0.01 to 0.1mol / L, the concentration of the monomethyl hydrazine is less than or equal to 0.15mol / L, and the concentration of the nitric acid is 0.8 to 1.2mol / L. The dissipation factor (DF) (Pu / U) in the 2D tank is more than 1,000, and the content of the plutonium in 2EU feed liquor reaches a uranium product index.

Description

technical field

[0001] The invention belongs to the technical field of nuclear fuel reprocessing, and in particular relates to a method for uranium purification cycle in a Purex (PUREX) process. Background technique

[0002] The PUREX process is a process that uses tributyl phosphate (TBP) as an extraction agent to separate and recover uranium and plutonium from reactor spent fuel. The PUREX process is mainly composed of a co-decontamination separation cycle and a uranium and plutonium purification cycle. The main task of the uranium purification cycle is to further remove traces of plutonium, neptunium and residual fission products in the uranium primary product liquid (1CU) from the co-decontamination separation cycle, so as to obtain a purer uranium product liquid.

[0003] In order to realize the separation of uranium and plutonium, foreign commercial reprocessing plants such as French UP2-800, UP3, and British THORP plants often use reducing agents such as hydroxylamin...

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