Objective: Examination and experimental reconstruction of the historical WBC measuring procedure in 1986 and estimation of the minimum detectable activity (MDA) of those measurements.
Materials and methods: 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.
Results and conclusions: 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.
Metoiu doslidzhennia ie eksperymental'ne vidnovlennia protsedury provedennia LVL vymiriuvan' 1986 roku ta otsinka ïkh minimal'no detektovanoï aktyvnosti.Materialy i metody. Doslidzhennia buly provedeni na gamma radiometri SRP 68 01 zi stsyntyliatsiy̆nym detekto rom na osnovi krystalu NaI(Tl) ∅ 30 x 25 mm2 ta odnokanal'nomu spektrometri NC 482 VM (firmy Bicron) zi stsyntyliatsiy̆nym detektorom na osnovi krystalu NaI(Tl) ∅ 52 x 52 mm2. U roboti vykorystano zakhysnu kameru eks pertnogo lichyl'nyka vyprominiuvannia liudyny (LVL), gomogenni fantomy tila liudyny z radioaktyvnym napov niuvachem, rezul'taty LVL vymiriuvan' patsiientiv radiatsiy̆nogo reiestru (RR) NNTsRM, otrymani za dopomogoiu LVL «Skrynner ZM». V roboti vykorystano dozymetrychni ta matematychni metody.Rezul'taty ta vysnovky. Vidnovleno protseduru provedennia LVL vymiriuvan' na pryladakh, iaki vykorystovuva lys' u 1986 rotsi dlia vyznachennia vmistu inkorporovanogo radiotseziiu u naselennia RZT. Za provedenoiu otsinkoiu minimal'no detektovana aktyvnist' LVL vymiriuvan', provedenykh u 1986 rotsi, lezhyt' u mezhakh vid 1,3 kBk · or ganizm 1 (u vypadku zastosuvannia odnokanal'nogo spektrometra NC 482 VM zi stsyntyliatsiy̆nym detektorom na os novi krystalu ∅ 52 x 52 mm2) do 7,4 kBk · organizm 1 (u vypadku zastosuvannia gamma radiometra SRP 68 01 zi stsyntyliatsiy̆nym detektorom na osnovi krystalu NaI(Tl) ∅ 30 x 25 mm2) dlia dorosloï liudyny pry chasi vymiriu vannia 60 s; vid 0,8 kBk · organizm 1 do 5,6 kBk · organizm 1, vidpovidno – dlia pidlitka; ta vid 0,5 kBk · organizm 1 do 3,8 kBk · organizm 1, vidpovidno – dlia dytyny.
Keywords: NC 482 ВМ one channel spectrometer; SRP 68 01 radiometer; WBC measurements; minimum detectable activity (MDA); radioactive cesium.
V. V. Vasynenko, O. M. Ivanova, L. O. Lytvynets, V. O. Pikta, G. M. Zadorozhna, M. I. Chepurnyi, I. A. Likhtariov.