Combustion Engineering (CE) Control Element Drive Mechanism (CEDM) coils have been in use for more than 40 years with a respectable operating history. However, the upper gripper coil, which is normally energized continuously in order to hold the control rod at the full out position, has been found to be under particular stress. As a result, the CE CEDM upper gripper coil is prone to early failures, accelerated by excessively high voltage or exposure to temperatures above its design value.