INVESTIGATION OF ENVIRONMENTAL RADIOACTIVITY AT A DECOMMISSIONED URANIUM MINE IN SOUTHERN CHINA

Area of Science:

• Environmental Science
• Radiological Science
• Nuclear Engineering

Background:

• Uranium mines can pose long-term environmental radioactivity risks even after decommissioning.
• Assessing residual radioactivity is crucial for public and occupational safety.
• Understanding radon and gamma radiation pathways is key for risk management.

Purpose of the Study:

• To conduct an environmental radioactivity survey at a uranium mine decommissioned for over 10 years.
• To measure key radiological parameters including dose rates, radon levels, and radionuclide concentrations.
• To evaluate the potential health risks to residents and employees from residual radioactivity.

Main Methods:

• Surface-absorbed dose rate in air measurements.
• Airborne radon and radon progeny concentration monitoring.
• Radon exhalation rate measurements from soil surfaces.
• Natural radionuclide concentration analysis in soil and surface water samples.

Main Results:

• Maximum annual effective dose from radon progeny inhalation: 1.74 mSv (employees) and 1.48 mSv (residents).
• Maximum annual effective dose from gamma-ray external radiation: 1.32 mSv (employees) and 1.16 mSv (residents).
• Specific measurements included dose rates, radon concentrations, exhalation rates, and radionuclide levels.

Conclusions:

• The environmental radioactivity survey indicates that radiation doses at the decommissioned uranium mine are within established safety limits.
• Inhalation of radon and radon progeny, along with external gamma radiation, are the primary contributors to the effective dose.
• Continued monitoring may be advisable to ensure long-term safety in the vicinity of the former uranium mine.