Izvestiya vuzov. Yadernaya Energetika

The peer-reviewed scientific and technology journal. ISSN: 0204-3327

Experience with Using the Coupled 1D-3D Thermal-Hydraulic Analysis to Simulate an Emergency Cooldown of a Sodium-Cooled Fast Reactor

9/17/2026 2026 - #03 Thermal physics and thermal hydraulics

Didenko D.V. Anfimov A.M. Nikanorov O.L. Rogozhkin S.A. Timin D.A. Fadeev I.D. Aksenov A.A. Zhestkov M.N. Kashirin V.S. Sazonova M.L. Sinitsyn A.V. Yushchenko A.A.

DOI: https://doi.org/10.26583/npe.2026.3.05

UDC: 621.039.5:(532+536) БН+621.039.513:621.039.526

A numerical study was performed of thermal-hydraulic processes in an advanced sodium-cooled fast reactor during an emergency cooldown. The simulation was performed with a coupled 1D-3D thermal-hydraulic analysis. The analysis uses FlowVision, a certified computational aero-fluid dynamics software package, and a 1D dynamic mathematical model of emergency heat removal system (EHRS) loops that is implemented in the SimInTech mathematical modeling environment. A 3D computer model has been developed for the reactor with a combined EHRS version — two channels with an autonomous heat exchanger (AHX) check valve and two channels without the AHX check valve. The model includes all the equipment main elements that take part in forming a coolant circulation path during the emergency cooldown. A mathematical model has been developed for the EHRS loops. The model describes thermal-hydraulic processes in a 1D approximation and takes into account time-dependent variations of parameters in EHRS loops. The 1D dynamic model of the EHRS loops is implemented in the SimInTech mathematical modeling environment and is connected to FlowVision via a network protocol. Through comparing calculated results with those calculated by the certified SOKRAT-BN/V2 computer program, it was verified that FlowVision coupled with the 1D mathematical model of EHRS loops can be used to calculate AHX parameters in a transient. The numerical simulation has been performed for a rated reactor operation mode and cooldown modes with four and two EHRS channels in action. The article presents a problem statement; a brief description of the coupled 1D-3D thermal-hydraulic analysis methodology for various reactor operation modes; for the 3D coolant flow, presented are numerical simulation results, which made it possible to assess the temperature level in different reactor regions and to confirm that paths of coolant natural circulation can form in the cooldown mode.

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computational study 1D-3D thermal-hydraulic analysis FlowVision SimInTech computer fluid dynamics CFD heat exchange sodium-cooled fast reactor reactor cooldown emergency heat removal system integrated layout core

Link for citing the article: Didenko D.V., Anfimov A.M., Nikanorov O.L., Rogozhkin S.A., Timin D.A., Fadeev I.D., Aksenov A.A., Zhestkov M.N., Kashirin V.S., Sazonova M.L., Sinitsyn A.V., Yushchenko A.A. Experience with Using the Coupled 1D-3D Thermal-Hydraulic Analysis to Simulate an Emergency Cooldown of a Sodium-Cooled Fast Reactor. Izvestiya vuzov. Yadernaya Energetika. 2026, no. 3, pp. 62-79; DOI: https://doi.org/10.26583/npe.2026.3.05 (in Russian).

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