RESPONSE CHARACTERISTICS OF RADIATION SURVEY INSTRUMENTS IN 85Kr AND 133Xe ENVIRONMENTS

Response characteristics of radiation survey instruments immersed in environments containing 85Kr or 133Xe gases were studied. The instruments were exposed to each of the noble gases at the center of a spherical chamber with a radius of 82.8 cm. The radiation survey instruments from Eberline1 (models RO-2, RO-3) with an ion chamber detector, and Technical Associates2 (model TBM3) and Ludlum3 (model 12) with GM detectors, were immersed in eight (8) different concentrations of 35Kr, 133Xe or both noble gases. Responses to the noble gases were recorded both during immersions and after exposures. The data suggested that the noble gases diffused during immersion into the detector volumes of the ion chambers resulting in timedependent responses during and after the exposures. The same pattern of responses was not observed with the survey instruments using GM detectors. Acknowledgement: This research was supported by Southern California Edison under contract No. 8T073901 while at San Diego State University. This work became possible with diligent support from David Deane and Kathryn McCarty while both were at San Diego State University. This work was partially supported by M&A Radiological and Environmental Monitoring and Assessment. Sections of this paper was published in Radiation Protection Management, V.16, No. 2, p. 22, 1999. ________________________________ 1. Eberline Corporation, P.0. Box 210S, Santa Fe, New Mexico. 2. Technical Associates, 7051 Eton Avenue, Canoga Park. California. 3. Ludlum Measurements, Inc., Sweetwater, Texas.