Resuspension of coarse fuel hot particles in the Chernobyl area

Measurements of resuspended aerosol in the Chernobyl 30-km exclusion zone h ave shown coarse fuel hot particles in the activity range 1-12 Bq Cs-137 pe r particle. The particles were sampled with newly designed rotating arm imp actors which simultaneously collect during the same experiment three sample s with fuel particles in the size ranges larger than 3 mu m, larger than 6 mu m and larger than 9 mu m in geometric diameter. The radionuclide ratios, determined after gamma-spectrometry, were in good agreement with the theor etical calculations for the radionuclide-composition of the Chernobyl Nucle ar 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 o f airborne hot particles were derived From digital autoradiography. For win d resuspension, maximal concentrations of 2.6 coarse hot particles per 1000 m(3) and during agricultural activities 36 coarse hot particles per 1000 m 3 were measured. The geometric diameter of single hot particles was estimat ed to be between 6 and 12 mu m. (C) 2000 Elsevier Science Ltd. All rights r eserved.