1989 neutron and gamma personnel dosimetry intercomparison study using RADCAL [Radiation Calibration Laboratory] sources

The fourteenth Personnel Dosimetry Intercomparison Study (i.e., PDIS 14) was conducted during May 1-5, 1989. A total of 48 organizations (33 from the US and 15 from abroad) participated in PDIS 14. Participants submitted by mail a total of 1,302 neutron and gamma dosimeters for this mixed field study. The type of neutron dosimeter and the percentage of participants submitting that type are as follows: TLD-albedo (40%), direct interaction TLD (22%), track (20%), film (7%), combination (7%), and bubble detectors (4%). The type of gamma dosimeter and the percentage of participants submitting that type are as follows: TLD (84%) and film (16%). Radiation sources used in the six PDIS 14 exposures included 252Cf moderated by 15-cm D2O, 252Cf moderated by 15-cm polyethylene (gamma-enhanced with 137Cs), and 238PuBe. Neutron dose equivalents ranged from 0.44--2.63 mSv and gamma doses ranged from 0. 01-1.85 mSv. One 252Cf(D2O) exposure was performed at a 60 degree angle of incidence (most performance tests are at perpendicular incidence). The average neutron dosimeter response for this exposure was 70% of that at normal incidence. The average gamma dosimeter response was 96% of that at normal incidence. A total of 70% of individual reported neutron dosimeter measurements were within ±50% of reference values. If the 0.01 mSv data are omitted, approximately 90% of the individual reported gamma measurements were within ±50% of reference values. 33 refs., 9 figs., 27 tabs