Year
2001
Abstract
The Finnish Nuclear Verification consortium (FINUVE) has gained experience in the utilization of aerosol sampling for Wide Area Environmental Sampling (WAES) in Iraq and in Kazakhstan. The work has been done within the framework of the Finnish support to the IAEA Action Team. During the field trial in Kazakhstan aerosol samples were collected during one year from the Semipalatinsk test site. Results obtained during the first 30 weeks are described in this paper. Weekly samples of about 25,000 m3 of air were collected. The total amount of dust was measured. g-spectrometry was used for the measurement of 7Be and 137Cs, a-spectrometry for 238Pu and 239,240Pu and ICP-MS for total uranium and the 235U/238U-ratio. The variation in the content of solid material and the 7Be concentrations are rather high. 137Cs can only be detected in a part of the samples. The total uranium varies considerably between the samples, while the 235U/238U-ratio can be determined with a precision of ± 2-10 %. Therefore rather small deviations can be distinguished. An improvement in analytical precision would be beneficial, but the increase in cost might be a problem. The ratio 238Pu/ 239,240Pu is a more sensitive indicator for plutonium than the 239,240Pu concentration. The ratio can be used to determine the origin and history of the plutonium and smaller deviations from the background can be detected.