Development of a Periodic Loading System using a Bellows

An instrumented capsule is one of the devices to investigate the irradiation effects of the nuclear reactor materials and components being used in a research reactor, HANARO. Among various capsules, a special capsule for in-pile creep and fatigue tests has been under development since 2002. A bellows was used to apply the constant load to the specimen in the creep capsule, and various studies have been performed to determine the specification of the bellows. But the load's concept for the fatigue test is slightly different with the creep test. It is necessary to repeat a force with a constant period and amplitude during the life of the specimen. Thus, for the fatigue test using an instrumented capsule, it is important to realize the load's shape being applied to the specimen. In this study, the out-pile loading system using the bellows to apply the actual fatigue capsule is developed, and it is performed by modifying the previous system which was developed for the out-pile creep test. The basic structure, the control system and the main function related to the new loading system are described, and the preliminary test results and the future works are also discussed