Case study: mapping of groundwater conditions at Olkiluoto site with electrical and electromagnetic soundings

Teollisuuden Voima Oy (TVO) carries out site investigations for the selection of the site for disposal of spent nuclear fuel. One of the five candidate areas is Olkiluoto island on the western coast, and where TVO's nuclear power plant is located. The bedrock at Olkiluoto is 1800 Ma old highly metamorphosed fractured gneiss. The characterization program comprises a sequence of investigations focussing on the modelleng and evaluation of groundwater flow conditions. One of the studies is the mapping of the existence of chemically different water bodies or layers down to the depth of 1000 meters