Development of simulation system for straight tube steam generator of sodium-cooled fast reactor; Application Study for structural integrity evaluation under heat transfer tube plugging condition

Yoshikawa, Ryuji  ; Imai, Yasutomo*; Tanaka, Masaaki  ; Ohshima, Hiroyuki

Accurate evaluation of three-dimensional temperature distribution is essentially required for the structural integrity analysis of large-sized straight tube steam generator (SG) of an advanced sodium-cooled fast reactor (SFR). Numerical simulation system TSG to analyze three-dimensional thermal-hydraulics in the straight tube SG has been developed. The three-dimensional simulation on sodium side by the CFD code FLUENT with porous body model was coupled with the multi-channel simulation on water/steam side. Fundamental validation of TSG code with the 1MWt straight tube SG test was performed. Temperature distribution of large-sized SG under the condition with plugged tubes was analyzed and the temperature deviation of heat transfer tubes was evaluated. Through the numerical simulation, local temperature increase near the plugged tubes was quantitatively evaluated, and the applicability of the simulation results to the structural integrity analysis of straight tube SG was indicated.