[en] The aim of this study is to develope interpretation methods to determine fracture porosity and directional properties of water filled fracture space in crystalline bedrock. Geophysical methods with high spatial resolution along the borehole are chosen for the study. This enables the analysis of individual fractures. The analyzed methods are the dipmeter, sonic log, and bed resolution density log. The spatial resolution of the sonic log is improved with a convolution filter. The proposed method for fracture aperture analysis utilizes peak values of anomalies. Equal area projection is used for visual presentation of the fracture porosity and directional properties of fracture space. A tensor presentation with probability correction is applied for matemathical presentation of fracture properties. The material for the study is from the investigations of the Loviisa nuclear power plant site in Finland. The results from the site reveal that fracture aperture is unevenly distributed. The fracture porosity tensor is strongly oriented to horizontal direction. Comparison with hydraulic tests indicated that the total fracture porosity is one or two orders of magnitude larger than the hydraulically determined effective flow porosity or kinematic porosity