According to IAEA Safety Standards “Geotechnical Aspects of Site Evaluation and Foundations for Nuclear Power Plants”, the subsurface conditions shall be identified.
Various types of in-situ tests should be carried out to measure the significant properties of the foundation materials. Uniaxial compressive strength and permeability of foundation are important indices to determine the subsurface condition at each site.
The strength of the soil/rock is a direct influence to foundation design. Meanwhile, the permeability may also influence the hydrogeological condition of the soil/rock layer, as such; permeability should be incorporated with the foundation design as well.