[en] Posiva Oy constructs an underground research facility ONKALO at Olkiluoto in Eurajoki. ONKALO is planned to be a part of the deep repository for the high level nuclear waste. Posiva Oy set up R20-programme for the years 2006-2008, with the target of having an acceptable grouting methodology in ONKALO. The programme was divided into three projects and the work and results of Technique-project is presented in this report. The implementation of the results (grouting design and execution) was outlined from the project. That work is under the responsibility of construction of the ONKALO-project. The Grouting Technique -project (INKE) studied the grouting experiences obtained from the first 2 km of the ONKALO access tunnel, searched for suitable grouting design approaches, carried out two grouting tests and one pilot grouting test with colloidal silica in ONKALO, analysed the expected grouting conditions in deep rock from the grouting point of view, studied the feasibility of so called optimal design solution in the expected grouting conditions. Based on these studies recommendations concerning the grouting design, design solutions for different rock conditions, grouting procedures, grouting stop criteria, the characterisation methods for grouting purposes, grouting materials and grouting work performance are presented. Swedish Time Stop Grouting, also named Grouting Time-Method was selected to be studied and used in this project and it was further developed. This work compiles the outcome of the project subtasks and presents the recommendations for developing the grouting in ONKALO. The key conclusion of this work are: (1) Grouting Time-method (time stop grouting) alone is not enough to be used as a grouting stop criterion due to the uncertainties related to the source parameters (fracture characteristics, rheological properties of grouts); these cause too high uncertainties when proving the sealing result via the grouting time, (2) due to the uncertainties related to the key source data, it is recommended that the grout flow is involved as a part of grouting stop criteria; It is possible to verify with the grout flow if the source data and made assumptions were accurate enough, (3) The ideal grouting design solution (in this project: the use of low pH cementious grouts, grouting holes inside the tunnel profile, limited grout take) from the long term safety point of view and the feasibility of it in different rock conditions is presented, but it can can be used seldom, because fractures are typically very small; the alternatives are to direct the grouting holes outside the tunnel profile, to use higher grouting pressures or to develop thicker and thinner grout mixes and take colloidal silica in use; the last alternative is recommended, (4) Part of groutings can done with typical designs for different rock conditions; the exceptions of this are major regional hydrogeological structures, shafts, postgroutings and fractures that intersects the tunnel drift, those should be designed invidually. Besides these, recommendations concerning the grouting design, equipments, grouting work, rock characterisation and implementation of the results of this project are presented in this work (orig.)