Published online by Cambridge University Press: 26 September 2014
The measurement performances of in vivo monitoring vehicles were studiedconsidering an increase in the radiological background in areas where the population isnot evacuated after a nuclear accident. The study focused on 137Cs and 131I Detection Limits (DLs) andcorresponding doses, for adults and one-year-old children. These DLs for groundcontamination were obtained experimentally using a grid of point sources. Then, the DLsand doses were calculated using the experimental data and a safety factor for two accidentscenarios. For these scenarios the 137Cs DL corresponds to a committed effective dose of0.02 mSv. The 131IDL corresponds to committed equivalent thyroid doses of 3 mSv (adult) and 30 mSv(one-year-old child). To guarantee a 45 mSv thyroid equivalent dose assessment for thechild the surface activity of 131I +132I +133I should be below 1.6 MBq/m2. This study shows that thevehicles can operate in a contaminated area where the population is not evacuated.However, in such a case, the contamination level outside and inside the vehicle should bekept stable to guarantee efficient body counting.