b'Power & Energy | Engineer Innovationthe magnitude of the reactor, the components, the operation, and the fission. Once sealed, it is impossible to test and measure the internal operating performance.With years of extensive reactor design experience, OKB GIDROPRESS knew their best chance to successfully design a new reactor system with improved safety and cost economics relied on a comprehensive digital twina virtual reactor model. The manufacturer had an established simulation process built in Simcenter STAR-CCM+ software, the computational fluid dynamics (CFD) tool from Siemens Digital Industries Software. The virtual reactor modelFigure 3: Details of the one billion cell computational mesh generated for CFD simulations in enabled the engineers at OKBSimcenter STAR-CCM+.GIDROPRESS to efficiently and accurately model the performance of all aspects of the nuclear reactors operation.To accurately assess the primary circuit The simulations helped the engineers atperformance, OKB GIDROPRESS OKB GIDROPRESS guarantee extremedeveloped one of the industrys largest fuel reliability, higher availability andCFD simulation models. The model improved performance. The result is aincluded every component of the modern reactor that is safe andprimary circuit in detail and is the only economical. model in the world to include the real profile of the pumps and the wheel Safest reactor; largest simulation rotation. Approximations and The worlds first Generation III+ nuclearsimplifications were kept to a bare reactor was born together with one ofminimum. Capturing the reactor the worlds largest engineeringgeometry accurately for simulation was simulation models, created in Simcentercrucial. The geometry preparation and STAR-CCM+. meshing tools in Simcenter STAR-CCM+ proved more than capable. The Vasilii Volkov, design engineer at OKBincredibly high-fidelity reactors GIDROPRESS, is one of the chiefcomprehensive digital twin clocked in architects of the simulations behind thejust shy of one billion computational VVER-1200. We do CFD simulations withcells and included multiphysics Simcenter STAR-CCM+ to make thesimulation of every aspect of the primary reactors better, cheaper and safer, sayscircuit.Volkov. The simulations help us optimize the thermohy-draulic behavior,Simcenter STAR-CCM+ is the only CFD understand failures and design faster. code that allows us to create simulations with a mesh size of one billion cells with Volkovs team has used Simcenter STAR- ease and accuracy, says Volkov. CCM+ for years. For the VVER-1200, OKBPreviously, it took us half a year to build GIDROPRESS pushed the code to itsa mesh. Now with Simcenter STAR-limits, modeling different equipment inCCM+, the whole process takes about a the reactor. The most importantweek to mesh and analyze.simulation is modeling the first primary circuit of the reactor. The primary circuitThe unsteady simulations of the primary is incredibly complex and provides thecircuit showed good agreement with first line of cooling for the reactor coreexperimental and measured data and using water to transfer all heat from thesignificantly reduced the design time for core. The integrity of the primary circuitthe primary circuit. The steam generator performance is the most critical aspectwas created based on previous designs, of reactor design, one which would beconfirmed and improved with CFD impossible without simulation. simulations.19'