Uranium series disequilibrium measurements at MOL and Whiteshell

The current contract is funding two parallel uranium series disequilibrium studies and the aims of and the progress to date of these studies are given in this report. The larger study is concerned with the measurement of uranium series disequilibrium in ground waters derived from sand layers above and below the Boom Clay formation at Mol in Belgium. For the 2 observation wells studied to date, the sand layers above the Boom Clay are characterised by low uranium content (< 0.01 dpm Kg-1) while below the Boom Clay, the sand layers are characterised by low to moderate uranium content (0.02 to 0.2 dpm Kg-1). There are marked uranium concentration differences below the Boom Clay at the two different sites. The second study will measure the ratio of 226Ra and 228Ra in large groundwater samples which have been scavenged by acrylic fibres impregnated with manganese oxide from the Underground Research Laboratory at Pinawa, Canada. (author)