Design of creep capsule for loading double specimen

In HANARO, multi-specimen loading creep capsule is presently being developed for raising the utilization property considering economy and efficiency in irradiation test. The creep capsule in this study is for loading double specimen. The test purpose of the creep capsule is to confirm the integrity of the loading unit and LVDT in the in-core irradiation condition and to evaluate the design parameters such as temperature, pressure and heat transfer coefficient estimated in the design stage. The previous creep irradiation test was performed at IP hole at which neutron flux was very low, so the capsule was designed with the concept of non-instrumentation capsule of which protection tube was very short. But the appearance of this capsule is same as the material instrumented capsule which has been successfully irradiated up to now in HANARO, so that it would not be damaged in the environment of high radiation. In order to control the temperature of the double specimen, the main heaters are located around the specimen and the sub-heaters are wound around the outside Al thermal media. The integrity for the capsule parts and the instruments which are doubly equipped in capsule will be confirmed in the in-core irradiation test, and the data will be applied for designing the 4 specimen loading creep capsule to be developed