Papers by Author: Hyeong Yeon Lee

Abstract: An assessment of a creep-fatigue crack growth for Mod. 9Cr-1Mo steel wide plates have been carried out based on an extended French high temperature design code, RCC-MR A16 guide. The defect assessment guide of the A16 provides assessment procedures on creep-fatigue crack growth for an austenitic stainless steel, but no guidelines are available yet for a Mod. 9Cr-1Mo steel. In this study, assessments of a creep-fatigue crack growth at defects of Grade 91 steel wide plates have been carried out based on the extended A16 method for austenitic stainless steel.

Abstract: A large scale sodium test facility of ‘CPTL’(Component Performance Test Loop) for simulating thermal hydraulic behavior of the Korean demonstration fast reactor components such as IHX(Intermediate Heat Exchanger), DHX(Decay Heat Removal Heat Exchanger) and sodium pump under development by KAERI is to be constructed. The design temperature of this test loop is 600°C and design pressure is 1MPa. The three heat exchangers are made of Grade 91 steel. Another sodium test facility of the ‘STEF’(Sodium Thermal-Hydraulic Experimental Facility) will be constructed next to the CPTL facility to simulate the passive decay heat removal behavior in the sodium cooled fast reactor. In this paper, the overall facility features of the CPTL and STEF are introduced and preliminary conceptual design of the facilities are carried out.

Abstract: Korea Atomic Energy Research Institute (KAERI) is in the process of carrying out a Nuclear Hydrogen Development and Demonstration (NHDD) Program by considering the indirect cycle gas cooled reactors that produce heat at temperatures in the order of 950°C. A coaxial doubletube hot gas duct (HGD) is a key component connecting the reactor pressure vessel and the intermediate heat exchanger (IHX) for the NHDD program. Recently, a preliminary design evaluation for the hot gas duct of the NHDD program was carried out. These preliminary design activities include a preliminary decision on the geometric dimensions, a preliminary strength evaluation, an appropriate material selection, and identifying the design code for the HGD. In this study, a preliminary strength evaluation for the HGD of the NHDD program has been undertaken based on the HTR-10 design concepts. Also, a preliminary evaluation of the creep-fatigue damage for a high temperature HGD structure has been carried out according to the draft code case for Alloy 617. Preliminary strength evaluation results for the HGD showed that the geometric dimensions of the proposed HGD would be acceptable for the design requirements.