Design requirement of in-pile creep capsule and experiment for the loading unit

Design requirement was described for design and manufacture of the in-pile creep capsule to test the creep behavior of various materials using HANARO, and the experiment for the loading unit was carried out as one of the design requisites. In the design requirement, some points to be considered for the real irradiation capsule were described and the concept for the fracture detectors were introduced which was not treated in the mock-up capsule. Detectors like LVDT and the strain gauge for high temperature are not only used to measure the displacement but to detect fracture of the specimen. They prevent failure of the experiment due to wrong detection of the specimen fracture. In the experiment for the loading unit, the loading mechanism in the mock-up capsule was reviewed and the force by the gas pressure into the bellows was investigated according to the gas pressure for the two commercial bellows. Through this experiment, the fact the load 60 ∼ 80kg suitable for the irradiation creep experiment was obtained without any boosting device in the He gas supply system was confirmed. Use of bellows whose diaphragms are more thick was recommended paying regards to the long term experiment in the reactor