Natural phenomena hazards evaluation of concrete silos 1, 2, 3 and 4 at Fernald, Ohio

Fernald Environmental Management Project (FEMP) is a United States Department of Energy (DOE) site located near Cincinnati, Ohio. FEMP was formerly established as the Feed Materials Production Center (FMPC) in 1951 under the Atomic Energy Commission. FEMP is currently undergoing site wide environmental remediation. This paper addresses four concrete silos built during the 1950s and located in Operable Unit 4 (OU-4). Silos 1 and 2 known as K-65 Silos contain residues from Uranium Ore processing. Silo 3 contains metal oxides in powder form. Silo 4 is empty. The Silos are categorized as low hazard facilities and the Natural Phenomena Hazards (NPH) performance category is PC-2, based on a recently completed safety analysis report. This paper describes the structural evaluation of concrete Silos 1, 2, 3 and 4 for NPH. Non Destructive Tests (NDT) were conducted to establish the current conditions of the silos. Analytical and computer methods were used to evaluate the stresses and displacements for different silo configurations and different loading combinations. Finite element models were developed to uniquely represent each silo, and analyzed using SAP90 computer program. The SAPLOT post processor was used for rapid determination of critical areas of concern for critical loading combinations and for varying silo configurations