A retention structure includes a center body including an outer surface, an enclosed end, an open end, and a contact section, the outer surface adapted to define a first portion of a flowpath, and the contact section extending radially outwardly from a centerline and located on the enclosed end and configured to reduce a radial and a torsional component of a first load that exceeds a first threshold applied to the contact section, when the turbine rotates and applies the first load to the contact section and an energy absorber coupled to the center body, disposed adjacent to the contact section, and having an outer surface adapted to define a second portion of the flowpath, the energy absorber further adapted to collapse, when the turbine rotates and contacts the energy absorber and applies a second load that exceeds a second threshold to the energy absorber.