[ RadSafe ] Kr-85

[Marcel Schouwenburg]

September 22, 2005

Thousands of curies of Kr-85 are released into the atmosphere each year 
from every nuclear power plant.  Such releases are environmentally 
inconsequential since Kr-85 is an inert gas and there is very limited 
human internal or external exposure after mixing with the total 
atmosphere. Exposure limits should be based on the possible immersion 
dose. Of course, Kr-85 that is being stored must be kept in a 
lead-shielded container to limit gamma and beta exposures.

You might slowly release mCi amounts through a laboratory chemical fume 
hood. Release of small amounts into the atmosphere will not lead to 
significant exposures, but you should first calculate the expected 
immersion dose to someone standing at the exhaust outlet using the 
dilution of the hood volumetric flow. If you have curie quantities you 
will have to make sure that you have carefully evaluated the dosimetric 
implications of possible immersion exposures during and after release to 
the atmosphere.

Otto

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Prof. Otto G. Raabe, Ph.D., CHP
Center for Health & the Environment
(Street Address: Bldg. 3792, Old Davis Road)
University of California, Davis, CA 95616
E-Mail: ograabe at ucdavis.edu
Phone: (530) 752-7754   FAX: (530) 758-6140
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