Thermal Striping Limits Analysis on the Cylinder With a Defect of Liquid-Cooled Nuclear Fast Reactors

Abstract The structural safety of the cylinder in liquid-cooled fast reactors is significantly affected by high-temperature thermal striping on the cylinder wall due to the free level fluctuation. Based on the elevated-temperature creep-fatigue evaluation theory of the RCC-MRx rules, combined with the finite element and numerical heat transfer analysis methods, a thermal analysis method appropriate for the fast reactor cylinder containing hypothetical cracks after being subjected to normal transient loads was established. The proposed model is validated compared with the test reactors, FAENA and SUPERSOMITE, and the calculated thermal striping limits agree with the experimental data. Furthermore, the involved model was implemented to predict the thermal striping limits for several ideal normal transients. Simultaneously, the effects of some key parameters, including the frequency, the heat transfer coefficient, wall thickness, and the mean temperature of the fluid on the thermal striping limit of the SS316 stainless steel cylinder were studied.