A field deployable high-resolution urine gamma analyzer

The Human Monitoring Laboratory has extended the use of its portable whole body counters to portable gamma spectrometers for urinalysis. The protocol tested measured a 120-mL sample in a polypropylene sample container for 5 min. Minimum detectable activities were estimated for Am-241, Co-57, Cs-137, and Co-60. The former is 113 Bq per sample, and the latter three are between 27-29 Bq per sample. Assuming an intake 5 d before the measurement, and all other parameters as default, the committed effective doses are 517 Sv, 76 mu Sv, 402 mu Sv, and 1.5 mSv, respectively. Clearly, this instrument can be used as a field deployable gamma spectrometer for urinalysis for activation and fission products, but actinides (and other low energy photon emitters) remain problematic.