Development of a program for high-temperature design evaluation according to RCC-MRx

•An elevated temperature design (ETD) evaluation program according to RCC-MRx was developed.•A web-based high temperature design evaluation program of the HITEP_RCC-MRx was developed.•Design-By-Analysis (DBA) of RB-3200 and Design-By-Rule (DBR) of RB-3600 in RCCMRx were programmed.•Comparisons were made between ASME-NH and RCC-MRx in terms of programmability.•Design limits on load-controlled stress, inelastic strain and creep-fatigue damage can be efficiently and reliably conducted. A web-based design evaluation program is developed for the elevated temperature design (ETD) analysis according to the RCC-MRx for Generation IV and fusion reactor systems. The program, named ‘HITEP_RCC-MRx,’ is composed of two modules: ‘HITEP_RCC-DBA,’ which computerizes the design-by-analysis (DBA) for class 1 components according to RB-3200 procedures, and ‘HITEP_RCC-PIPE,’ which computerizes the design-by-rule (DBR) analysis for class 1 piping according to RB-3600 procedures. Each module performs three major design evaluations on load-controlled stress, inelastic strain and creep-fatigue damage in a reliable and efficient way. The program is verified with a number of components and piping systems in sodium test facilities subjected to high temperature loading for the DBA module and the DBR module, respectively. Since HITEP_RCC-MRx is programmed with web-based language, it can operate on a smartphone as well as on a personal computer once it is connected to an internet or WIFI. Comparisons of the ETD codes of RCC-MRx and ASME Section III Subsection NH are made in terms of the programmability and reproduction of the evaluation results. A new creep model proposed for Grade 91 steel is incorporated in the program for comparison of creep behaviors between the creep models of RCC-MRx and the new Garofalo creep model for Grade 91 steel. Comparisons for verification between the evaluation results from HITEP_RCC-MRx and direct calculations using Excel confirm that the HITEP_RCC-MRx performs ETD evaluations in an efficient and reliable way.