Plutonium dioxide particle imaging using a high-resolution alpha imager for radiation protection

Area of Science:

• Nuclear Physics
• Radiation Detection
• Occupational Health

Background:

• Worker exposure to inhaled plutonium dioxide particles in nuclear facilities is a significant radiation protection concern.
• Accurate real-time measurement of particle size and activity is essential for internal dose assessment.

Purpose of the Study:

• To develop and validate a high-resolution alpha imager for real-time measurement of plutonium dioxide particles.
• To determine activity median aerodynamic diameter values at nuclear facility work sites for improved internal exposure evaluation.

Main Methods:

• Development of a high-resolution alpha imager utilizing a ZnS(Ag) scintillator, optical microscope, and EMCCD camera.
• Real-time measurement setup for individual alpha particle location identification and plutonium dioxide particle sizing.
• Gaussian fitting for spatial resolution evaluation and count rate analysis for equivalent volume diameter calculation.

Main Results:

• Achieved an average spatial resolution of 16.2 ± 2.2 μm FWHM for multiple alpha particles (5x zoom).
• Determined a spatial resolution of 302.7 ± 4.6 μm FWHM for plutonium dioxide particles.
• Confirmed negligible influence of beta particles and successful discernment of alpha particles in mixed contamination.

Conclusions:

• The developed alpha imager is effective for real-time plutonium dioxide particle measurement in nuclear facilities.
• This technology supports accurate internal exposure dose evaluation for enhanced worker safety.
• The system enables precise characterization of radioactive particles for radiation protection.