Papers by Author: Jae Han 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: This paper deals with the creep-fatigue defect growth behavior at the defect front of a high temperature cylindrical structure subjected to a cyclic axial tensile loading and a thermal loading in the LMR(Liquid Metal Reactor) structures. The defect growth evaluation was carried out per the France RCC-MR A16 guide and UK R5 code and their results were compared. The creepfatigue structural test to confirm the evaulated results was carried out with a induction heater. The defect front was investigated at every 100th cycle of a testing by using the metallurgical inspection technique with an optical microscope. From these results, we showed that the creep-fatigue defect behavior of a high temperature structure can be predicted with a conservatism by following the RCC-MR A16 guide and the R5 code.