Description of Source:
The radiation systems of underground uranium mines emit large amounts of radon into the air. Radon is a radioactive gas, known to cause lung cancer in humans.

The Standard: 
Emissions of radon to ambient air from an underground uranium mine shall not exceed those amounts that would cause any member of the public to receive an annual effective dose equivalent of 10 mrem/yr.

Reporting Requirements: 
Mine owners and operators must calculate the effective dose equivalent to any member of the public and report this information to EPA each year. Annual reports should include the results of emissions testing and dose calculations; a list of emission points and their distances to the nearest residence, school, business/office, and producing farm; and a description of emission controls.

More Information:
Electronic Code of Federal Regulations (e-CFE): 40 CFR 61, Subpart B
EPA Radiation Protection Division NESHAPs Home Page