[en] Posiva Oy contracted Suomen Malmi Oy (Smoy) to core drill the drillholes for grouting work of the exhaust air shaft in ONKALO. The work took place in several phases between 16th of May and 15th of October 2009. The identification numbers of the drillholes are ONK-PP183-ONK-PP198 and ONK-PP201. The drilling rig used was hydraulic Sandvik DE 130. Extra stabilized NQ2 drilling equipment was used to ensure maximum straightness of the drillholes. The drillhole diameter with the equipment used is 75.5 mm and sample diameter is 50.5 mm. 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. The deviations of the drillholes were surveyed with EMS-Reflex device during drilling and when the drillhole was finished. Water loss measurements were conducted in the drillholes to estimate the need for grouting and to measure if the grouting operation was successful. (orig.)