Method for selective extraction separation of trivalent actinides and lanthanides in fuel-short after-treatment

Abstract

The invention discloses a method for selective extraction separation of trivalent actinides and lanthanides in fuel-short after-treatment. The method is implemented through the steps that NTAamide(n-Oct) serves as an extraction agent, kerosene serves as a diluting agent, a water-soluble ligand TEE-BisDGA serves as a detergent, a hydroxycarboxylic complexing agent or ammoniacarboxylic complexing agent or a nitric acid solution serves as a stripping agent, and a multi-stage extraction technology is utilized, firstly, a large number of actinide elements and part of lanthanide elements are extracted from feed liquid through the extraction agent, then the lanthanide elements in a loaded organic phase are removed through the detergent, finally the actinide elements are stripped from the organicphase through the stripping agent, thus selective extraction separation of the actinide elements and the lanthanide elements can be realized, the recovery rate of the actinide elements exceeds 99%, and the recovery purity can reach 99.9% or above.

Description

technical field [0001] The invention belongs to the technical field of nuclear fuel cycle and nuclear waste treatment, relates to a process system for separation of lanthanides / actinides, in particular to a method for selective extraction and separation of trivalent actinides and lanthanides in spent fuel based on a multi-stage extraction process. Background technique [0002] The effective handling and disposal of nuclear fuel is one of the key factors to ensure the sustainable development of nuclear energy. The "separation-transmutation" method is a nuclear fuel reprocessing method that is generally preferred in the world. Its main point is to selectively separate the small but highly toxic actinides from the high-level waste liquid by solvent extraction, and extract It transmutes into short-lived or stable nuclides (Gu Zhongmao et al., Atomic Energy Science and Technology, 2002, 36(2): 160-167). [0003] In actual extraction and separation, single-stage extraction often ...

AI Technical Summary

Problems solved by technology

[0010] Although currently targeting An 3+ / Ln 3+ Separation has developed some multi-stage extraction process systems, but there are still many deficiencies in the process of practical application, such as: poor stability of extractant, poor extraction kinetics, low loading of organic phase, complex extraction system, etc.

Therefore, a kind of good An that is suitable for industrial scale application has not yet been developed. 3+ / Ln 3+ Multi-stage extraction separation system

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