By Tiffany Adams
Students at the University of New Mexico and North Carolina State University tackled real-world questions through senior design projects recently with assistance from INL employees. Aided by the coordinated help and expertise of university faculty and INL advisers, students examined specific questions affecting special-purpose and modular high-temperature gas-cooled reactors.
In the case of students at UNM, Carlo Parisi, a nuclear engineer and research and development scientist, served as the INL adviser for a small group of students enrolled in Cassiano de Oliveira's senior design class during the spring 2018 semester. The students in Parisi's group tackled the problem of designing a cask to safely transport a special-purpose reactor. SPRs are smaller than traditional reactors and can be deployed by truck, barge, rail or airplane to remote locations such as military bases or isolated villages. Once a reactor has been operational and is being prepared to be moved to a long-term storage site, it needs to be adequately shielded in order to protect workers and the public from radiation during transport.
Using an INL report detailing two conceptual designs of SPRs and Nuclear Regulatory Commission guidelines, UNM students used a Monte Carlo code base developed at Los Alamos National Laboratory to calculate the radiation that would be produced after five years of reactor operation. The students then used this measurement to determine the amount of shielding needed to adequately insulate the reactor.
Jonathan Paz, a student in Parisi's group, said the engineer's involvement in the project led to a "wonderful experience. Parisi treated us like we were colleagues, and we were expected to meet goals and produce deliverables," Paz said. "This was so much more rewarding and fun than working on just another homework assignment."
Students at NCSU tackled a different set of problems during the 2017-2018 school year. NCSU students investigated the potential for load following, or the adjustment of a reactor's energy output to match the varying daily energy demand, in a modular high-temperature gas-cooled reactor. Guided by Aaron Epiney, a physicist at INL, Kostadin Ivanov and Maria Avramova, both professors at NCSU, and Paolo Balestra, an NCSU postdoctoral research scholar, students used both RELAP5-3D and PHISICS software applications to determine the ability of a modular HTGR to load follow.
Epiney's involvement in the project was a bit broader than Parisi's, giving general advice based on his experience as a member of the team that built PHISICS and coupled it with RELAP5-3D.
"The students were very curious," Epiney said. "They asked, 'Can we investigate this?' or 'Does it make sense to run these kind of calculations?' I just made sure they didn't waste time. They were pretty free. They investigated the physics and tried to understand what was happening, then drew their conclusions."
For both student groups, the end result was a paper and presentation at the American Nuclear Society Student Conference in Gainesville, Florida, in early April.
NCSU students presenting at the ANS Student Conference in Gainesville
Although the students don't plan on continuing to research these questions after graduation, their experience will assist in their future professional ventures. "This project was valuable to our education because this process and set of constraints are not unlike those we will be expected to face in a professional environment," Paul Yang, a student at UNM, said. Keion Henry, an NCSU student, echoed Yang's sentiments, saying, "This taught me some valuable lessons on how reactors respond to certain scenarios and how various cases with various changed parameters must be run in order truly establish an examined relationship."
In addition, their efforts and findings will not go on unused, according to Parisi. "The next team could use the existing code input deck to improve the shielding design and begin to perform structural analyses in order to meet all NRC requirements for a safe shipping."
Overall, the collaboration was a benefit to both INL and the students. "It was definitely a positive experience," Parisi said.