Permeability Characteristics of Subsurface Material in Experimental Power Reactor Site, Puspiptek - Serpong

Permeability is defined as ability of a rock, sediment, or soil to allow pore fluid and gases to pass through it. Permeability is one important parameter in site investigation and subsurface haracterization. Permeability on this research delivered from in-situ test which is falling head and packer test. Tests are
implemented on 5 m of soil or rock interval in line with drilling progress. Result of test then compared with available data on physical characteristics which is lithology, gamma-ray log, and density log. Lugeon generated from calculation could also benefit for interpretation of water flow in rock and condition of rock mass discontinuities. Permeability of soil in Serpong Formation range from 2.09E-4 to 1.00E-3 cm/s, classified as medium to high, and in Bojongmanik Formation range from 5.26E-6 to 3.83E-5 cm/s, classified as very low to low. In
groundwater characteristic of Serpong Formation is aquifer and Bojongmanik Formation is
aquiclude. Water flow characteristic in rock dominantly is turbulent, subsequently void filling
and laminar. Lugeon value of rock in DH-11 and DH-12 range from 0.3 to 1.46 or very tight
to tight in term of rock mass discontinuities.