PUBLIC EXPOSURE TO EXTERNAL GAMMA RADIATION ON A MINE LANDFORM COVERED BY LOW URANIUM GRADE WASTE ROCK

Area of Science:

• Environmental Science
• Radiation Protection
• Mining Rehabilitation

Background:

• The Ranger uranium mine is undergoing rehabilitation, creating a final landform.
• Assessing public radiation exposure is crucial for post-mining land use.
• External gamma radiation is a key exposure pathway to consider.

Purpose of the Study:

• To assess public exposure to external gamma radiation on the planned final landform.
• To compare external gamma radiation dose rates with other exposure pathways.
• To inform rehabilitation planning for uranium mining sites.

Main Methods:

• Calculated average above-background dose rate from external gamma radiation.
• Compared gamma radiation dose rates to inhalation pathways (radon progeny, dust).
• Averaged annual effective dose over the entire Ranger Project Area for envisioned land use.

Main Results:

• The average above-background dose rate from external gamma radiation was 6.0 × 10-3 mSv d-1.
• This dose rate is significantly higher than inhalation pathways.
• The above-background annual effective dose was approximately 4.1 × 10-2 mSv.

Conclusions:

• External gamma radiation is a significant exposure pathway for the public at the Ranger mine rehabilitation site.
• The findings provide guidance for assessing rehabilitation plans at uranium mining sites.
• This study highlights the importance of considering external gamma radiation in landform rehabilitation.