Experimental reconstruction of historical WBC measuring procedure in 1986

Examination and experimental reconstruction of the historical WBC measuring procedure in 1986 and estimation of the minimum detectable activity (MDA) of those measurements.

The SRP 68 01 gamma spectrometer with attached scintillation detector based on a NaI(Tl) O 30 x 25 mm2 crystal and NC 482 ВМ one channel spectrometer (Bicron Co.) with attached scintillation detector based on a NaI(Tl) O 52 x 52 mm2 crystal were used for the study. Protective chamber of the expert type whole body counter (WBC) and homogenous human body dummy phantoms filled with dry radioactive material were applied. Results of measurements on the WBC «Screener 3M» were retrieved from the Radiation Registry of the NRCRM. Dosimetry and mathematical methods were applied too.

The WBC measurement procedure was reconstructed using the examples tested in 1986 to assay the level of incorporated radioactive cesium in population of contaminated territories. MDA under the WBC measurements in 1986 was found being from 1.3 kBq per human body using the NC 482 ВМ one channel spectrom eter with attached scintillation detector based on a NaI(Tl) O 52 x 52 mm2 crystal up to 7.4 kBq per human body using the SRP 68 01 gamma radiometer radiometer with attached scintillation detector based on a NaI(Tl) O 30 x 25 mm2 crystal in adults under the 60 seconds measurement time. The respective values for adolescents and chil dren were within 0.8-5.6 kBq per body and 0.5-3.8 kBq per body.