Decay-Associated Fluorescence for Boron Determination in Uranium-Based Nuclear Fuels

Area of Science:

• Analytical Chemistry
• Nuclear Chemistry
• Spectroscopy

Background:

• Accurate boron determination is crucial in uranium-based nuclear fuels.
• Traditional methods face challenges with overlapping spectra and high background fluorescence.
• Sensitive and selective analytical techniques are needed for nuclear fuel analysis.

Purpose of the Study:

• To develop a novel, simple, sensitive, and cost-effective method for boron determination.
• To utilize time-resolved fluorescence spectrometry to overcome spectral interferences.
• To provide a method applicable to uranium-based nuclear fuels, including enriched samples.

Main Methods:

• Complexation of boron with chromotropic acid, a fluorescent ligand.
• Application of time-resolved fluorescence spectrometry to differentiate ligand and complex decay times.
• Utilizing decay-associated spectra (DAS) to eliminate ligand fluorescence background.
• Validation using U3O8-based ILCE Standards and analysis of enriched uranium fuel samples.

Main Results:

• Achieved a wide linear dynamic range (5-100 ppb) with excellent linearity (r² > 0.998).
• Demonstrated high precision (<5% at 10 ppb, <4% at 50 ppb) and a low detection limit (1.5 ppb).
• Reported high recovery rates (>94%) for spiked boron in uranium samples.

Conclusions:

• The developed time-resolved fluorescence method offers superior sensitivity and selectivity for boron determination in uranium fuels.
• Reduced sample size requirements, leading to decreased uranium recovery from analytical waste.
• Eliminated the need for organic solvents, making the method more environmentally friendly and cost-effective.