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RPI to Lead Project on Nuclear Reactor Safety
Rensselaer Polytechnic Institute is leading a $3 million research project that will pair two of the world’s most powerful supercomputers to boost the safety and reliability of next-generation nuclear power reactors. The three-year project, titled “Deployment of a Suite of High Performance Computational Tools for Multiscale Multiphysics Simulation of Generation-IV Reactors,” is funded by the U.S. Department of Energy and will create highly detailed computer models of a new proposed type of nuclear reactor. These models could play a key role for the future development of the new reactors, which meet stringent safety and nonproliferation criteria, can burn long-lived and highly radioactive materials, and can operate over a long time without using new fuel.
Running simulations of such a vast virtual model, where scientists can watch the reactor system perform as a whole or zoom in to focus on the interaction of individual molecules, requires unprecedented computing power.
Rensselaer nuclear engineering and engineering physics professor Michael Podowski, a world-renowned nuclear engineering and multiphase science and technology expert who also heads Rensselaer’s Interdisciplinary Center for Multiphase Research, is project director and principal investigator of the new study.
Podowski said nuclear power should likely gain traction and become more widespread in the coming decades, as nations seek ways to fulfill their growing energy needs without increasing their greenhouse emissions. Nuclear reactors produce no carbon dioxide, Podowski said, which gives this energy source an advantage over coal and other fossil fuels for large-scale electricity production.
The type of reactor that Podowski’s team will be modeling, a sodium-cooled fast reactor, or SFR, is among the most promising of these next-generation designs. The primary advantage of the SFR is its ability to burn highly radioactive nuclear materials, which today’s reactors cannot do, Podowski said.
Whereas current reactors source their power from uranium, SFRs can also source their power from fuel that is a mixture of uranium and plutonium. In particular, SFRs will be able to burn both weapons-grade plutonium and pre-existing nuclear waste, Podowski said. Thanks to their high temperatures, SFRs will also produce electricity at higher efficiency than current nuclear reactors.
So along with producing less toxic waste, SFRs should be able to actively help reduce the amount of existing radioactive materials by burning already-spent nuclear waste, he said. SFRs also offer a viable, productive way to start getting rid of the world’s stockpile of weapons-grade nuclear fuel.
Podowski’s team will construct an incredibly detailed computer model of an SFR. The model will allow researchers to zoom in and watch as individual molecules of fission gas and fuel material interact with other molecules inside the reactor, or zoom out to simulate and test the behavior of the reactor as a whole. Creating such a model, not to mention running hundreds or thousands of simulations with slightly modified models and conditions, requires a tremendous amount of computing power and would not be possible without the help of supercomputers, Podowski said.
In order to construct the model and run these massive simulations, Podowski’s team will develop and deploy a suite of powerful, high-performance software tools capable of performing such a task. Since no one computer code or technology is robust enough to model the wide variety of systems that comprise an SFR, the team will use different computer codes for different parts of the model and then develop new ways of linking those differently coded segments together into a single, cohesive, seamless package.
The researchers will use simulations to study fuel performance, local core degradation, fuel particle transport, and several other aspects of the SFRs. By better understanding how design and operational issues will affect the reactor at different stages in its life cycle, Podowski said, the new study will help to dramatically improve the design and safety of SFRs long before the first physical prototype is ever built.
“Nuclear reactors are safe, but nothing is perfect,” Podowski said. “So the issue is to anticipate what could happen, understand how it could happen, and then take actions to both prevent it from happening and, in the extremely unlikely instance of an accident, be able to mitigate the consequences.”
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