Settlement Experienced at a Recently Licensed Nuclear Station

The settlement experienced at a recently licensed nuclear station demonstrated the need for coordination among geologists, geotechnical engineers and structural engineers to ensure that essential geological knowledge and experience is applied to the design and construction of the structures. The nuclear station had been under construction for a number of years when unexpected settlements were noticed which caused significant concrete cracking of the nuclear service water intake structure. The “seismic Category I” intake structure has an internal dimension of 12 feet wide by 15 feet high, a length of 167 feet with the thickness of walls and roof varied from 2 feet 6 inches to 3 feet. This paper describes the details of the problem including the original exploration and design, the extent of investigation following the discovery of the structural cracks, the evaluation of the causes of settlement and conclusions