The U.S. Department of Energy (DOE) awarded a three-year $875,000 grant for a team of Pittsburgh scientists, including Anirban Jana of the Pittsburgh Supercomputing Center (PSC), to develop computational models for turbulent mixing in the VHTR (Very High Temperature Reactor), a Generation IV nuclear reactor.
Generation IV reactors offer significant advances in sustainability, safety, reliability and economics. Their designs are currently undergoing study through the Generation IV International Forum (GIF), comprised of 12 countries including the United States, and are expected to be available commercially after 2030.
Jana, co-principal investigator on the project, will collaborate with Mark Kimber (principal investigator) and John Brigham of the University of Pittsburgh Swanson School of Engineering and Milorad Dzodzo of Westinghouse Electric Company. The collaboration, says Jana, who will guide the computational modeling thrust of the project, pulls together expertise both in experimental study and computational modeling along with Westinghouse’s multi-decade experience in nuclear engineering.
The focus of the study is turbulent mixing in a portion of the VHTR called the “lower plenum” — where helium that has absorbed heat from the nuclear reaction enters at speeds up to 100 meters per second and at temperatures approaching 1000º C. The high flow speed and non-uniform heating cause turbulent mixing and temperature fluctuations that affect the structural reliability of the lower plenum.
The team will use several sophisticated computational fluid dynamics software packages to simulate the complicated flow dynamics and thermal stresses involved. For some of the simulations and for analyzing the large datasets that will be generated, says Jana, the team expects to use PSC’s Blacklight system, an SGI Altix UV1000 system partitioned as two connected 16-terabyte shared-memory systems, the two largest shared-memory systems in the world.
They expect also to use other resources of XSEDE (Extreme Science and Engineering Discovery Environment), the National Science Foundation cyberinfrastructure program. The aim is to build a computational model that is validated and verified with available experimental data, and which then can provide confidence as a design tool to better understand stresses and refine the design of the VHTR lower plenum.