A turboalternator system includes a turboalternator having a rotatable member operatively engaged to a bearing set, a radial support element, and a contact structure engaged with the radial support element. The rotatable member defines a first end, a second end and an axis of rotation. The turboalternator system is configured to be thermally adjustable such that in a first thermal condition the contact structure is at a first radial position with respect to the axis of rotation and contacts the rotatable member to provide support, and in a second thermal condition the contact structure is at a second radial position with respect to the axis of rotation that is spaced further from the axis of rotation than the first radial position. The contact structure includes a ring having a groove formed in an outer diameter surface thereof, and the radial support element engages the groove in the contact structure.