Seismic Analysis of the National Compact Stellarator Experiment (NCSX)

Abstract

DOE requirements as outlined in DOE-STD-1020-2002 are followed for determination of the necessity for seismic qualification of the stellarator and its related systems. IBC-2000 is followed for the qualification requirements The NCSX criteria document[2] provides guidance on load combinations. The stellarator presents minimal occupational hazards and hazards to the public. The qualification effort is intended to preserve the viability of continuing the experiment after an earthquake, and to explore the sensitivity of the design to dynamic loading from sources other than normal operation. A response spectra modal analysis has been employed. The seismic model builds on available conceptual design and design models of the vessel, and modular coil. Outer TF and PF coil models and models of the cold mass supports have been generated and added to form a complete model of the stellarator system. Much of the stellarator is robust to resist normal Lorentz forces. Areas sensitive to lateral loads and dynamic application of non-Lorentz loading, include the nested cylinder cold mass support columns, cantilevered vessel ducts, and the radial guides connecting the vessel ducts and modular coil shell. Loads on these structures are quantified, and design adequacy is assessed.