Radiological analysis for radioactivity depth distribution in activated concrete using gamma-ray spectrometry.

Area of Science:

• Nuclear Engineering
• Radiation Detection and Measurement
• Materials Science

Background:

• Activated concrete is a significant radioactive waste in nuclear facilities.
• Accurate assessment of radioactivity depth distribution is essential for safe handling and disposal.
• Existing methods can be time-consuming or require sample removal.

Purpose of the Study:

• To develop and validate an in-situ method for analyzing radioactivity depth distribution in activated concrete.
• To establish the correlation between the Peak to Compton (PTC) method and radioactivity depth profiles.
• To evaluate the feasibility of field application of the developed PTC method.

Main Methods:

• Development of in-situ measurement techniques using a high-purity germanium (HPGe) detector.
• Application of the Peak to Compton (PTC) method to measure ¹⁵²Eu emissions from activated concrete.
• Validation through MCNP (Monte Carlo N-Particle) simulations and comparison with sample analyses.

Main Results:

• Experimental results showed agreement within 3% relative error with MCNP simulations for radioactivity depth distributions.
• A clear correlation was derived between PTC method values and radioactivity depth distribution.
• Field application in cyclotron facilities yielded results with less than 20% relative error compared to sample analysis.

Conclusions:

• The developed in-situ PTC method provides a rapid and accurate means to evaluate radioactivity depth distribution in activated concrete.
• The method's robustness was confirmed through simulations considering material variations.
• Further research is needed to extend the analysis to diverse radioactive structures in nuclear facilities.