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Air and Water:  

Subpart B: Underground Uranium Mines


Subpart B protects the public and the environment from the radon-222 emissions to the ambient air from underground uranium mines. It sets a limit on the emission of radon-222 that ensures that no member of the public in any year receives an effective dose equivalent of more than 10 mrem/year.

When these mines are operating, their ventilation systems emit large amounts of radon into the atmosphere.  Radon in an unventilated mine is hazardous to miners. Ventilating to reduce radon exposure to the miners increases exposure to the general population.

Owners/operators of each mine must calculate the effective dose equivalent to any member of the public and report this information to EPA annually. 

All sampling done during data collection must follow EPA-approved procedures. The computer model COMPLY-R About ZIP(COMPLY-R Users Guide) is approved for calculating effective dose equivalents, and EPA may approve other procedures with advanced notice.  (Please note that COMPLY-R is a version of COMPLY that includes radon gas emissions. COMPLY does NOT include radon emissions and should not be used for Subpart B calculations.)

In addition, there are general requirements that all facilities subject to any NESHAP must meet, 40CFR61, Subpart A: General Provisions Exit EPA Disclaimer.


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