The fuel test loop consisted an in-pile test section (IPS) and an out-pile system (OPS) is an nuclear fuel irradiation test facility installed in HANARO and its operating temperature and pressure are similar to those of commercial nuclear power plant’s. Penetration pipe connecting the IPS and OPS at the reactor concrete wall is supported by pool-wall pipe support. The existing pool-wall pipe support established in the HANARO have insulations even thought the leak tightness is not ensured. So, the need for an isolation of the insulations from the HANARO cooling water makes the existing pool-wall pipe support newly designed. In this study a structural evaluation for the pool-wall pipe support in accordance with the 2001 ASME B&PV Section III NF is implemented. The most critical primary and secondary stress intensities occur at the modified connection area of the main cooling water pipe and plate ring, but those values are less than the allowable stress. It is concluded that the existing pool-wall pipe support could be modified to a newly designed shape having an isolated insulation from a HANARO cooling water.

Highspeed steels (HSS) with a combination of good wear resistance and toughness are finding new, non-cutting applications such as rolls and rollers. In this paper, the research interests are focused on the microstructural evolution of a SMo-6W series high speed steel during HIPping and the effect of HIPping process parameters on its microstructure and properties. HIPping process variables includes; temperature, pressure and hold time. The microstructures of the HIPped HSS were examined by SEM, OM and X-ray diffraction whereas the properties measured were the relative density, hardness, and bend strength at room temperature. In HIPped materials, MC and M6C were the major carbides formed in a matrix of martensite. The effect of powder size on the microstructure and mechanical properties of HIPped materials was insignificant. However, HIPping temperature and hold time strongly affected the carbide size and distribution. The results show that at proper HIPping temperature and pressure conditions, the final products approach the full density ( > 99% RD). The particle boundaries were completely eliminated without an eminent microstructural coarsening. The bend strength was about 2.3 Gpa, which is superior to cast HSS. At excessive HIPping temperatures, rapid carbide coarsening occurred, thus deteriorating the mechanical properties of the P/M steels.