DOSIMETRY OF EXTERNAL PHOTON RADIATION

Parameters influencing the external doses to people living in areas wi th radioactive fallout, and methods for theoretical estimations of the se doses, are discussed. The results from two different individual dos e measurement projects after the Chernobyl accident are presented, one performed in the highly contaminated regions close to the power plant (Brjansk region of Russia), and the other in less contaminated areas far from the power plant (Oystre Slidre in Norway). In the former, mea n monthly effective doses of 200-250 mu Sv were measured, in the latte r 66-95 mu Sv, both results including a natural background contributio n of about 60 mu Sv. The results from the Norwegian programme correlat e fairly well with published conversion factors between ground activit y levels and effective dose equivalent values, while the observed resu lts in the Brjansk region are lower than theoretical estimates.