In 2010, the University of Michigan was chosen as one of the core partners of The Consortium for Advanced Simulation of Light Water Reactors (CASL) the first U.S. Department of Energy Innovation Hub. The purpose of the consortium is to provide advanced modeling and simulations for commercial nuclear reactors.
“The University of Michigan was assigned several tasks as part of the CASL effort to augment existing modeling and simulation reactor tools by creating the next generation environment for predictive simulation of light water reactors. This modeling and simulation environment has been designated the Virtual Reactor and will be based on state-of-the-art computational methods for modeling multi-physics phenomena in a nuclear reactor, including neutronics, thermal-hydraulics, structural mechanics, and materials performance,” said Bill Martin, professor of Nuclear Engineering and Radiological Sciences (NERS) at the U-M who also has a major leadership role in CASL as the Head of Modeling and Numerical Methods Focus Area. The initial five-year grant ends in 2015.
Last July, the team of Michigan faculty and students successfully tested a high fidelity neutronics code called MPACT that accurately predicts, and provides a detailed description of what is going on inside a light water reactor. This development has the potential to be a significant milestone in nuclear reactor safety.
“As a student working on the code, it was both a motivating and humbling experience,” says Brendan Kochunas who was a PhD candidate at the time and part of the CASL team. “At a university it is difficult to get all the information necessary to simulate a real reactor. But working with so many talented people gave me that opportunity and it’s been an invaluable experience for me.” Kochunas was the recipient of the “CASL Knight Award” the first year of the program for technical contribution, edging out numerous others from other universities and laboratories.
In a bit of reverse engineering, the University of Michigan team finalized the theory behind the method and developed the code to provide 3D resolution of the neutron flux within the fuel pin. Now there is a way to get insight into the physics of what’s happening inside the ten of thousands of fuel pins throughout the lifetime of the fuel in a reactor, phenomena that have been hard to explain in the past. The university can make this code available to the industry so that nuclear reactor design and research can be safer.
“In our experience with the Virtual Environment Reactor Applications core simulator (VERA-CS), we have been impressed by its accuracy in reproducing past reactor start-up measurements. These results give us confidence that VERA-CS can be used to anticipate the conditions that will occur during the AP1000 reactor start-up operations. This new modeling capability will allow designers to obtain higher-fidelity power distribution predictions in a reactor core and ultimately further improve reactor performance,” said Bob Oelrich, manager of PWR Core Methods at Westinghouse, one of the partners in CASL, in a Science News article.
According to Tom Downar, a professor of NERS and a lead researcher on the project, being able to develop this code will have almost immediate applications. “Because of the CASL partnership with Westinghouse, the work of the faculty, researchers and students will have industry value. This code won’t be put on a shelf to collect dust, which can happen at a university. What we are doing is accelerating the pipeline of research with the ideas we come up with at the University of Michigan being applied to real world industry with immediate added value. This is important to the Department of Energy and the U.S. taxpayers who are sponsoring this research.”
By simulating scenarios inside a nuclear reactor and understanding the neutronics, safer power plants can be designed and built, strengthening the position of U.S. companies.
“CASL is evidence of what can happen when there is a marriage between the university, U.S. national laboratories and industry,” said Downar. “A U-M PhD student was an intern at Westinghouse running simulations. This is an example of how the University of Michigan is producing the next generation of nuclear engineers,” said Downar.
“There will soon be an initial release of the code through the managing CASL partner Oak Ridge National Laboratory.” CASL and the University of Michigan are in the process of applying for a renewal of CASL with the expectation to extend the methodology to other reactor designs.
Eleanor Shelton contributed this story.