Retrospective estimation of the concentration of super(241)Pu in air sampled at a Belgrade site following the Chernobyl accident

The surface air activity concentration of super(241)Pu for the period May 01-15, 1986, for a monitoring site in Vinca, Belgrade was retrospectively estimated. The results were obtained by re-measurement of plutonium fraction alpha-spectrometric sources, with super(236)Pu as a tracer, used almost 13 years earlier for the determination of super(239,240)Pu concentration in surface air immediately after the Chernobyl accident. The estimated super(241)Pu concentration, based on the super(241)Am in-growth method for air samples, ranged from 240 to 7800 mu Bq/m super(3). The average activity ratio super(241)Pu/ super(239,240)Pu originating from the Chernobyl accident at Belgrade site was approximately 100 at the collection time.