Engineering geological and geotechnical assessment of floor of Control Building of Nuclear Reactors-7&8 of Rajasthan Atomic Power Project, Rawatbhata, India

To verify whether in-situ conditions have been realistically estimated during investigation and to furnish the permanent data set for the interpretation of geological conditions, foundation floor mapping of important structure like control building of nuclear power plant is essential. At Rawatbhata, adjacent to existing Rajasthan Atomic Power Project (RAPP) units 1 to 6, two units of 700 MWe each Pressurized Heavy Water Reactor (PHWR) type Nuclear Reactors are being constructed. Engineering geological mapping on 1:100 scale was carried out for Control Building of NB-7&8. Geotechnical assessment of the foundation of control building was done on the basis of detailed engineering geological mapping, geological drill holes logging data, rock mass permeability values, geophysical profiling and laboratory test results. Based on the field observations and evidences, it was found that the entire floor area consists of fine to medium grained, compact greyish white quartzitic sandstone and yellowish brown ferruginous sandstone. The floor region was seen to contain certain iron stained and weathered zone. No evidence of faulting or shearing was observed on the surface of the floor area. Keywords—nuclear reactor; control building; engineering geological; raft foundation; discontinuity; Rawatbhata