Isotopic composition of plutonium immissions in Austria after the Chernobyl accident

Alpha-spectrometric Pu determinations in aerosol samples collected after the Chernobyl accident in Austria show a²³⁸Pu/²³⁹ (240)Pu ratio in the range of 0.33–0.76 with a most reliable value of 0.47. From²⁴¹Am measurements in old Pu preparations and air filter analyses also²⁴¹Pu activities have been calculated. The ratio²⁴¹Pu/^{239 (240)}Pu during the main contamination period is 74.6±5.7, when maximum²⁴¹Pu concentrations in air achieved 4.5–6.0 mBq/m³.