Evaluating the performance of the ORTEC® detective™ for emergency urine bioassay

The performance of the ORTEC® Detective™ as a field deployable tool for emergency urine bioassay of ¹³⁷Cs, ⁶⁰Co, ¹⁹²Ir, ¹⁶⁹Yb and ⁷⁵Se was evaluated against ANSI N13.30. The tested activity levels represent 10 % RL (reference level) and 1 % RL defined by [Li C., Vlahovich S., Dai X., Richardson R. B., Daka J. N. and Kramer G. H. Requirements for radiation emergency urine bioassay techniques for the public and first responders. Health Phys (in press, 99(5), 702-707 (2010)]. The tests were conducted for both single radionuclide and mixed radionuclides at two geometries, one conventional geometry (CG) and one improved geometry (IG) which improved the MDAs (minimum detectable amounts) by a factor of 1.6-2.7. The most challenging radionuclide was ¹⁶⁹Yb. The measurement of the mixture radionuclides for ¹⁶⁹Yb at the CG did not satisfy the ANSI N13.30 requirements even at 10 % RL. At 1 % RL, ¹⁶⁹Yb and ¹⁹²Ir were not detectable at either geometry, while the measurement of ⁶⁰Co in the mixed radionuclides satisfied the ANSI N13.30 requirements only at the IG.