Analysis of fine debris released from Chernobyl-4

Debris has been analyzed from clothing worn at Kiev immediately after the Chernobyl-4 reactor accident. Gamma spectra showed that a limited number of mixed fission products was present (Zr/Nb, Ru, Cs and Ce); the presence of zirconium and cerium activity implied that some of the fuel was mechanically suspended as an aerosol during the accident. Some of the debris was found to consist predominantly of uranium (19% by number), and there was also evidence for a small number of cerium- and ruthenium-rich particles. Particles containing heavy elements were identified by electron back-scattering, while SEM/EDS and SIMS were used to study the elemental and chemical constituents of the uranium, zirconium, iron and copper rich particles. Although no cesium-based particles were found, cesium was associated with almost all of the uranium rich debris