Commissioning and Testing of Active Magnetic Bearings for HTR Production Fuel Ball Blowers

High temperature gas cooled reactor (HTR) nuclear power plants depend on high-performance fluid machinery, including helium circulators and fuel ball blowers, for safe, reliable and efficient operation. Active magnetic bearings (AMB) have been utilized in all recent high temperature helium-cooled reactor designs as the only mature oil-free bearing technology to provide high reliability and availability of operations for these highly demanding applications. With the successful operation of the prototype, HTR production fuel ball blowers have been manufactured and the commissioning and qualification testing have been recently completed. This paper describes the technical challenges, solutions and results in the commissioning phase, and the qualification testing of the HTR production fuel ball blowers. The qualification testing included running the machine with helium gas to ensure the cooling and thermal conditions of the machine were stable at the maximum speed condition. The bearing temperatures, vibration levels and bearing dynamic loads were measured and were all as expected. In addition, five full speed landings were successfully performed on one of the production fuel ball blower machines.