In this study, thermal-hydraulic analysis of partial loss of coolant flow accident in supercritical pressure light water reactor (SCWR) with a new geometric design has been investigated. In the new design, the coolant and moderator circuits are separated. This analysis was performed using the development of a transient-state thermal-hydraulic code in which the equations of mass, momentum, and energy are solved. The porous Media approach is used to solve these equations. By extracting the results of transition modeling, it is observed that in the new geometric design, by separating the coolant and moderator circuits, the maximum fuel clad temperature is lower than the maximum fuel clad temperature value of the previous designs. As in the new design at the end of the transition, the maximum fuel clad temperature has decreased by about 37% compared to the initial state. The result of the calculations in this study shows that the new design, in which the coolant and moderator circuits are separated, has created more safety in a chosen transition.
• A thermal-hydraulic computer code was developed to analyze the SCWR reactor core in transient mode.
• Porous media approach for a thermal-hydraulic analysis of the SCWR core has been implemented.
• In the new design, the amount of reactor thermal power at the end of the transition reaches 5.5% of the initial value.
• The results have been improved compared with those of Oka’s design.