Radioactive Liquid Waste Solidification with Boron Control
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Solution Overview
Problem
Current methods for processing radioactive liquid waste containing boron, such as cement solidification, face issues with delayed setting and reduced strength due to boron's interference with the cement hardening reaction, and existing techniques like alkali metal compound additions do not consistently achieve long-term high-strength solidified products with volume reduction.
Innovation Solution
A method involving adjusting the alkali metal/boron molar ratio to 0.8 or more in the radioactive liquid waste, followed by drying to form a powdered waste, and then mixing with kneading water and a hydraulic inorganic solidifying material for solidification, which inhibits borate ion polymerization and enhances the stability and strength of the final product.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cement solidification is used to process radioactive liquid waste containing boron, then the waste can be solidified, but the setting and hardening reaction of cement is retarded and strength is deteriorated
Solution Approach 1:
The patent applies preliminary action by adjusting the alkali metal/boron molar ratio to 0.8 or more before cement solidification. This pre-adjustment of chemical composition prevents boron from interfering with the cement hardening reaction, thereby maintaining both solidification effectiveness and final strength.
Solution Approach 2:
The patent changes the chemical parameter of the waste solution by controlling the alkali metal/boron molar ratio to 0.8 or more. This parameter change transforms the chemical environment to be compatible with cement solidification, resolving the contradiction between achieving solidification and maintaining strength.
2Quantity of substance
If the liquid waste is concentrated to supersaturation and then solidifying material is added, then volume reduction is achieved, but sodium borate absorbs water and forms hydrate causing false setting and deteriorated strength
Solution Approach 1:
The patent applies preliminary action by adjusting the alkali metal/boron molar ratio before concentration and solidification. This pre-adjustment prevents sodium borate from absorbing water and forming hydrates that cause false setting, thereby maintaining process stability while achieving volume reduction.
Solution Approach 2:
The patent applies preliminary anti-action by controlling the chemical composition to counteract the tendency of sodium borate to absorb water and form hydrates. This prevents the harmful effect of false setting while allowing volume reduction through concentration.
3Ease of manufacture
If conventional methods are used to process boric acid liquid waste, then the waste can be treated, but long-term high strength cannot be achieved due to boron interference with cement hardening
Solution Approach 1:
The patent changes the chemical parameter by controlling the alkali metal/boron molar ratio to 0.8 or more, which eliminates boron's interference with cement hardening. This enables both easy treatment feasibility and long-term high strength in the solidified product.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach results in a solidified product with long-term high strength and significant volume reduction of the waste, while maintaining process stability and preventing false setting, thereby overcoming the limitations of previous methods.
Implementation Method 1
a hydration reaction between a solidifying material such as a cement and water is prevented
Implementation Method 2
sodium borate absorbs water and forms a hydrate whereby the plasticity is lost very quickly to cause false setting
Data Source
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AI summary
A method for processing a radioactive liquid waste containing boron of the present invention includes: a molar ratio control step of adding an alkali metal or an alkali metal compound to a radioactive liquid waste containing boron to control an alkali metal/boron molar ratio in the radioactive liquid waste to be 0.8 or more; a drying step of drying the radioactive liquid waste having the controlled molar-ratio using a dryer to form a powdered waste; a dissolving step of mixing the powdered waste with kneading water to prepare a solution; and a kneading step of adding a hydraulic inorganic solidifying material to the solution, and kneading the hydraulic inorganic solidifying material and the solution for solidification.