A method in non-destructive testing for lead shielding exceeding 25 kg/m² using ¹⁸F.

Area of Science:

• Radiation Protection
• Materials Science
• Nuclear Engineering

Background:

• Non-Destructive Testing (NDT) is crucial for verifying lead shielding integrity in radiation protection.
• Existing NDT methods for lead shielding are limited for thicknesses exceeding 25 kg/m².
• Accurate assessment of lead barrier thickness is essential for regulatory compliance.

Purpose of the Study:

• To develop a reproducible 'in the field' NDT method for lead barriers > 25 kg/m².
• To utilize a Fluorine-18 (18F) radioactive source for NDT applications.
• To establish an empirical equation and methodology for assessing lead shielding thickness.

Main Methods:

• Monte Carlo (MC) simulations using PENELOPE and PENGEOM to model lead attenuators up to 302.7 kg/m².
• Empirical validation of simulated Transmission Factor (TF) data using 18F source.
• Measurements conducted at Source-to-Detector Distances (SDD) of 38.1 cm and 52.7 cm.

Main Results:

• Simulated TF curves correlated with empirical data up to 162.4 kg/m² (38.1 cm SDD) and 138.0 kg/m² (52.7 cm SDD).
• Deviations observed beyond these thicknesses due to significantly reduced measurable transmissions.
• SDDs > 23 cm were found to provide sufficient near narrow beam conditions for the proposed NDT configuration.

Conclusions:

• The developed method using an 18F source shows promise for NDT of thick lead barriers (> 25 kg/m²).
• The study provides a foundation for in-situ verification of radiation shielding.
• Transmission data will be made available to facilitate further research and application.