Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method for extracting and recycling neptunium from spent fuel aftertreatment waste liquid

A spent fuel extraction technology, applied in the field of nuclear waste treatment and recycling, can solve only 1-2 problems

Active Publication Date: 2017-10-13
CHINA INSTITUTE OF ATOMIC ENERGY
View PDF5 Cites 10 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But, there is a problem in 30% TBP-diluent organic phase extraction, promptly 30% TBP-diluent organic relative tetravalent neptunium is also only 1-2 under the situation that acidity is higher, needs to be extracted at high acidity (4mol / L or more nitric acid), high salt concentration and strong salting-out effect, multi-stage extraction is designed to ensure sufficient extraction rate for neptunium.
In this way, when extracting neptunium, it is necessary to use a higher concentration of nitric acid or add a lot of salt, which is extremely unfavorable for reducing the generation of radioactive waste

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for extracting and recycling neptunium from spent fuel aftertreatment waste liquid
  • Method for extracting and recycling neptunium from spent fuel aftertreatment waste liquid
  • Method for extracting and recycling neptunium from spent fuel aftertreatment waste liquid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] Example 1: Research on the Extraction Ability of P350 to Neptunium and the Reduction Ability of Reductant to Neptunium

[0034]Through research, it is found that the extraction ability of P350 to hexavalent neptunium and tetravalent neptunium is much higher than that of tributyl phosphate. Specifically, when the concentration of nitric acid in the aqueous neptunium solution is 3mol / L, and the concentration of neptunium is 0.05g / L, use 5% (v / v) P350-diluent to extract the system and 5% (v / v) TBP - The diluent extraction system extracts the aqueous phase (the ratio is 1:1, and the extraction time is 5 minutes), and after the extraction, a certain volume of the aqueous phase and the organic phase are respectively taken to measure the concentration of neptunium in them by α energy spectroscopy. The ratio of the concentration of neptunium in a certain valence state in the organic phase to the concentration of neptunium in the corresponding valence state in the aqueous phase ...

Embodiment 2

[0045] Example 2: Method for recovering neptunium from spent fuel reprocessing waste liquid through two extraction-stripping processes (1)

[0046] The experimental bench was installed in the glove box to extract and recover neptunium in the waste liquid of the spent fuel reprocessing plant.

[0047] The first extraction-stripping process is as figure 2 As shown, the process steps are:

[0048] (1) After evaporating and concentrating the spent fuel reprocessing plant waste liquid, use sodium metavanadate as oxidant seasoning, 15mol / L HNO 3 Adjust the acidity to 4mol / L to obtain the feed liquid 2NAF to be purified. 2NAF contains Np, U, Pu and split elements, Np mainly exists in the form of Np(VI), and Pu mainly exists in the form of Pu(IV).

[0049] (2) 2NAF is introduced into the 2NA extraction tank, and 5% (v / v) P350-kerosene is also introduced into the 2NA extraction tank as the extraction agent 2NAX, 3mol / L HNO 3 As the detergent 2NAS, the flow ratio of 2NAF to 2NAX wa...

Embodiment 3

[0056] Example 3: Method for recovering neptunium from spent fuel reprocessing waste liquid through two extraction-stripping processes (2)

[0057] The first extraction-stripping process is as figure 2 As shown, the process steps are:

[0058] (1) Add reducing agent (0.1-1.0mol / LFe(NO 3 ) 2 ) to reduce Np to tetravalent and Pu to trivalent, use 5mol / L HNO 3 Adjust the concentration of nitric acid to 4mol / L to obtain the feed liquid 2NAF to be purified.

[0059] (2) 2NAF is introduced into the 2NA extraction tank, and 5% (v / v) P350-kerosene is also introduced into the 2NA extraction tank as the extraction agent 2NAX, 3mol / L HNO 3 As the detergent 2NAS, the flow ratio of 2NAF to 2NAX was 2:1. After extraction, more than 99.5% of U and Np were co-extracted into the organic phase 2NAP.

[0060] (3) Introduce the organic phase 2NAP obtained in step (2) as 2NBF into the 2NB stripping tank, and also introduce 0.1mol / LHNO in the 2NB stripping tank 3 As stripping agent 2NBX, 5%...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention belongs to the technical field of nuclear waste treatment and recycling, and relates to a method for extracting and recycling neptunium from spent fuel aftertreatment waste liquid. The method comprises following optional order-replaceable repeatable steps, and water phase back-extraction matte is finally collected. The steps comprise 1, neptunium in a neptunium-containing water phase solution is oxidized to be hexavalent, and an organic solvent containing dimethyl phosphonate (1-methyl heptyl) ester is added under the strong acid condition for extraction; organic phases are collected, a reducing agent is added, reextraction is carried out under the dilute acid condition, and therefore hexavalent neptunium in the organic phases is selectively reduced to be pentavalent and reextracted to enter a water phase; 2, a reducing agent is used for reducing neptunium in the water phase solution to be tetravalent, and an organic solvent containing dimethyl phosphonate (1-methyl heptyl) ester is added under the strong acid condition for extraction; and organic phases are collected, reextraction is carried out under the dilute acid condition, and therefore tetravalent neptunium in the organic phases is reextracted to enter the water phase. By means of the method, a neptunium nitrate solution with standard purity can be prepared.

Description

technical field [0001] The invention belongs to the technical field of nuclear waste treatment and recovery, and relates to a method for extracting and recovering neptunium from spent fuel reprocessing waste liquid. Background technique [0002] The spent fuel of power reactor nuclear power plant contains a certain amount of neptunium, the content varies according to the burnup of spent fuel, the content of neptunium-237 in the spent fuel of 33000 burnup is about 500-600g / tU. During the reprocessing of spent fuel, plutonium and uranium are mainly recovered, while neptunium-237 is left in the radioactive waste liquid. The neptunium-237 left in the radioactive waste liquid will enter the solidified body if it is not extracted. Neptunium-237 has strong mobility in solidified bodies, which is not conducive to the safety of geological repositories. At the same time, neptunium-237 can be used as a raw material and converted into plutonium-238 by irradiation, becoming an importan...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): C22B60/02
CPCC22B60/026
Inventor 李峰峰蒋德祥何辉唐洪彬刘金平周贤明
Owner CHINA INSTITUTE OF ATOMIC ENERGY
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com