Beiträge zur mikrochemischen analyse langlebiger uranspaltprodukte in staubproben

A microchemical qualitative and quantitative separation process for long-lived radionuclides from uranium fission (Cs, Sr, Ce, Zr, Ru) in dust samples is described. The loaded dust filter is moistened with carrier solution and with borax-sodium carbonate, and ashed in an electrically heated platinum spiral; the dust is thus decomposed, forming beads. The solution of the bead in dilute acid is concentrated in a ring with the ring oven ; the paper bearing the radioactive ring is cut into sectors and a specific precipitation reaction is applied for each nuclide in separate sectors. Identification and determination are carried out by autoradiography of the sectors. Practical testing was done with a 2.5-year old dust sample originating from nuclear studies in 1961–62 ; radioactive Cs, Sr and Ru were detected in 1.7 mg of dust ash. The quantitative evaluation of strontium-90 of the order of 10^-12 C showed the sensitivity of the method. The range of application of the method is indicated.