Calculations of the deposition of Cs-137 from nuclear bomb tests and from the Chernobyl accident over the province of Skane in the southern part of Sweden based on precipitation

The deposition of Cs-137 over the province of Skane (an area of about 100 x 100 km(2)) in the southern part of Sweden has been investigated. The origi n of the deposition of Cs-137 is, in about equal parts, from nuclear weapon s tests and from the Chernobyl nuclear accident and amounts to about 1-3 kB q/m(2). The activity concentrations of Cs-134 and Cs-137 in soil samples fr om 16 sites distributed in a grid pattern over the investigated area have b een measured and the depositions,from the nuclear weapons tests and from th e Chernobyl accident have been separated. These pre- and post-Chernobyl act ivities have been compared with depositions calculated from measurements of the activity concentrations of Cs-134 and Cs-137 in precipitation at two p laces and from measurements of the precipitation from a network of between 113 and 143 precipitation stations. Comparisons with in situ measurements a nd:with aerial survey measurements have also been made. The agreement is go od and it has been possible to gain a good and detailed knowledge in retros pect of the deposition from measurements of the deposition per mm of precip itation from just a few stations, and of the:precipitation from a network o f stations. (C) 2000 Elsevier Science Ltd. All rights reserved.