Keywords: Monte Carlo simulation, MCNPX, whole body counter, WBC, HPGe detector, ionising radiation, low radiation, occupational exposure, accidents, radionuclides, dose assessment, radiation exposure
A Monte Carlo simulation of a whole body counter
The preparedness of response to the accidental incorporation of radionuclides into the human body by inhalation or ingestion is a subject of major concern due to the generalised use of ionising radiations in medical and industrial applications. Following a radiological or nuclear accident or in case of occupational exposure due to an accidental dispersion of radionuclides, a rapid methodology is necessary to evaluate the consequences of such events to professionals and members of the public. Efforts are currently under way at the Nuclear and Technological Institute (ITN, in Sacavem, near Lisbon) to set up and operate a Whole Body Counter (WBC) for the survey of the activity and the dose assessment in the case of radionuclide incorporation in the aforementioned accidental scenarios. The WBC of ITN includes a Hyperpure Germanium (HPGe) detector and a phantom, as well as a calibration source. To study and better understand the behaviour of the WBC detection system, Monte Carlo (MC) simulations have been performed using the state-of-the-art MC computer code MCNPX to create a computational set-up of the WBC. The simulation results were compared against experimental data and the corresponding results are reported in this work.