A NEW EXTREMITY SYSTEM AND PERFORMANCE AT INEL

The TLD extremity dosimetry system described herein incorporates the c omponents necessary for personnel extremity monitoring to meet current and proposed requirements. Single and dual element TLD dosemeters, ra nging in thicknesses from 20 to 100 mg.cm(-2), and appropriate filtrat ion comprise the extremity detectors which are uniquely identified by bar code labels. A dose algorithm used in conjunction with the dosemet ers and TLD reader technology are capable of reporting shallow dose H- p(0.07) from betas, low and high energy photons using any combination of these dosemeters. Performance tests and results were obtained by th e Idaho National Engineering Laboratory (INEL) Operational Dosimetry U nit in the evaluation of a single extremity dosemeter capable of simul taneously monitoring beta and high energy gamma. Four TL materials and two filter types were tested in various combinations to Cs-137 photon s, uranium slab, Sr-90/Y-90, and Tl-204 beta, irradiations. An overvie w of the current INEL system dosemeter response, linearity, angular de pendence, residual, and effects of physical damage to the dosemeter we re tested. The results of these tests, presented here, lead to the pre liminary conclusion that an extremity dosemeter can be constructed to monitor beta and high energy gamma radiation simultaneously.