Two types of cartridges to be attached to full face Gass masks, which are commercially available and have been in use for the purpose of preventing inhalation hazard due to airborne radioactive materials for a few years at JAERI, were examined for the performance of removing airborne radioiodine in order to obtain data necessary for establishing a guide of the radiation protection in wearing them.
The airborne radioiodine-131 discharged ieto the exhaust system during the processing of iodine-131 at the radioisotope production plant was used for the tests, the concentrations of which ranged from 10
-5 μCi/cc to 10
-8 μCi/cc. The tests were carried out at the flow rate of 20 1/min (moderate work) and 40 1/min (medium hard work), respectively, in conditions of ralative humidities being over the range from 50% to 70%.
This paper describes the experimental results on the penetration of airborne radioiodine two types of cartridges as a function of the period of air flow and discusses the relationship between the concentration and the service time, considering the leakage at seal between the mask and face.
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