ONKALO pose experiment. Core drilling of drillholes ONK-PP223...226, ONK-PP253...261 and ONK-PP268...272 in ONKALO at Olkiluoto 2009-2010

Suomen Malmi Oy (Smoy) core drilled 14 drillholes in two phases for Posiva's Olkiluoto spalling experiment (POSE) in ONKALO at Eurajoki, Olkiluoto in April - July 2010. The identification numbers of the holes are ONK-PP253-261 and ONK-PP268 ..272, and the lengths of the drillholes range from 1.37 to 7.53 metres. The drillholes are 75.7 mm by diameter, except for drillhole ONK-PP259 which is 101.3 mm by diameter. The hydraulic DE 130 drilling rig was used for the work. The drilling water was taken from the ONKALO drilling water pipeline and premixed sodium fluorescein was used as a label agent in the drilling water. In addition to drilling, the drillcores were logged and reported by geologist. Geological logging included the following parameters: lithology, foliation, fracture parameters, fractured zones, core loss, weathering, fracture frequency, RQD and rock quality. The main rock types in the drillholes are pegmatitic granite and veined gneiss. The average fracture frequency in the drill cores is 0.7 pcs / m and the average RQD value 99.3 %. In addition, this working report includes a drilling technical memorandum of ONKPP223... 226, drilled in December 2009. (orig.)