Characterization And Monte Carlo Simulations Of A 4-Liter NaI Detection System For Use During Nuclear And Radiological Emergencies And For The Detection Of Nuclear Materials

SCK•CEN is engaged in research related to the use of a large volume NaI detection system for use during nuclear and radiological emergencies, for the detection of nuclear materials and for the characterization of contaminated sites. As part of this effort, a research activity is being carried out to determine the characteristics and build a Monte Carlo model of the available 4 liters NaI detector. These activities consist of: Determination of energy resolution, efficiency, lower threshold, background in laboratory conditions using well-characterized point sources; Modeling and validating of the detector by Monte Carlo simulations; Determination of the response function by combining measurement and simulation results; Characterization of the detector for contaminated surfaces by measurements and modeling (2D source, 9 m2 containing 133Ba and 137Cs); Calibration of detector for dose rate measurements This paper focuses on the results obtained so far concerning the Monte Carlo model and its validation with experimental data.