Community Research and Development Information Service - CORDIS


Samples of groundwater from a granite fracture at the Grimsel test site in Switzerland have been collected as part of a second intercomparison of groundwater colloid sampling and characterisation techniques carried out by members of the 'Coco Club' (colloids and complexes) sponsored by the CEC. This report describes the Harwell contribution to this exercise. The bulk of naturally occurring actinides was found to reside in solution with less than 10% associated with colloids. The colloid concentration determined by electron microscopy was 1.0 E10 particles/l (detection limit approx. 50nm) for samples determined by three laboratories. The colloids were shown to be negatively charged using microelectrophoresis and to be relatively stable. There was evidence of a reduction in the pH of the water after storage due to air contamination. This has served to identify the problems associated with colloid sampling and characterisation techniques.

Additional information

Authors: LONGWORTH G, Harwell Laboratory, Uranium Series Disequilibrium Section, Didcot (GB);IVANOVICH M, Harwell Laboratory, Uranium Series Disequilibrium Section, Didcot (GB)
Bibliographic Reference: EUR 12766 EN (1990) 23 pp., FS, ECU 5
Availability: (2)
ISBN: ISBN 92-826-1485-9
Record Number: 199011212 / Last updated on: 1994-12-01
Original language: en
Available languages: en