Risikovurdering av helikopteroperasjoner i områder forurenset med utarmet uran (DU)

A risk assessment of LIS helicopter operations in areas contaminated with depleted uranium (DU) has been performed. Based on the assumption that the dust from 65 rounds of 190 g DU is whirled up in a volume of 27000 m3 and that the wind velocity is 1m/s, the maximal amounts of inhaled DU is calculated to 3.4 mg. This represents a radiation exposure of 0.4 mS. The maximal tolerated dose proposed by ICRP for a worker is 20 mS/y (4). This suggests that 50 helicopter operations a year may be performed in a DU contaminated area without exceeding the maximal tolerated radiation dose. The maximal tolerated air concentration based on the chemical toxicity of uranium suggests that 18 helicopter operations may be performed a year without exceeding the maximal tolerated dose. Based on this, and the information given by FMI it seems unlikely that helicopter operations should pose a serious risk to the crew.