Resuspension of coarse fuel hot particles in the Chernobyl area

Abstract

Measurements of resuspended aerosol in the Chernobyl 30-km exclusion zone have shown coarse fuel hot particles in the activity range 1-12 Bq 137Cs per particle. The particles were sampled with newly designed rotating arm impactors which simultaneously collect during the same experiment three samples with fuel particles in the size ranges larger than 3μm, larger than 6μm and larger than 9μm in geometric diameter. The radionuclide ratios, determined after γ-spectrometry, were in good agreement with the theoretical calculations for the radionuclide-composition of the Chernobyl Nuclear Power Plant at the moment of the accident and the measured hot particles in soil in the early years after the accident. The number concentrations of airborne hot particles were derived from digital autoradiography. For wind resuspension, maximal concentrations of 2.6 coarse hot particles per 1000m3 and during agricultural activities 36 coarse hot particles per 1000m3 were measured. The geometric diameter of single hot particles was estimated to be between 6 and 12μm. Copyright (C) 2000 Elsevier Science B.V.