Classification of hot particles from the Chernobyl accident and nuclear weapons detonations by non-destructive methods

Both after the Chernobyl accident and nuclear weapon detonations, agglomera tes of radioactive material, so-called hot particles, were released or form ed which show a behaviour in the environment quite different from the activ ity released in gaseous or aerosol form. The differences in their character istic properties, in the radionuclide composition and the uranium and actin ide contents are described in detail for these particles. While nuclear bom b hot particles (both from fission and fusion bombs) incorporate well detec table trace amounts of Co-60 and Eu-152, these radionuclides are absent in Chernobyl hot particles. In contrast, Chernobyl hot particles contain Sb-12 5 and Ce-144 which are absent in atomic bomb HPs. Obvious differences are a lso observable between fusion and fission bombs' hot particles (significant differences in Eu-152/Eu-155, Eu-154/Eu-155 and Pu-238/Pu-239 ratios) whic h facilitate the identification of HPs of unknown provensence. The ratio of Pu-239/Pu-240 in Chernobyl hot particles could be determined by a non-dest ructive method at 1:1.5. A non-destructive method to determine the content of non-radioactive elements by K-alpha-emission measurements was developed by which inactive Zr, Nb, Fe and Ni could be verified in the particles. (C) 2001 Elsevier Science Ltd. All rights reserved.