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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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Latest News
Denver Airport may go nuclear
Colorado’s first nuclear power plant of the 21st century could be built at an unconventional site: the Denver International Airport (DEN).
In its mission to gain energy independence and become the greenest airport in the world, DEN has announced that it will conduct a feasibility study to determine the viability of building a small modular reactor on its 33,500-acre campus.
S. Stimpson, A. Graham, B. Collins
Nuclear Science and Engineering | Volume 195 | Number 7 | July 2021 | Pages 778-793
Technical Paper | doi.org/10.1080/00295639.2021.1871994
Articles are hosted by Taylor and Francis Online.
Recent efforts in MPACT have focused on improving the performance of the 2D/1D subplane implementation to help target computational performance goals. This paper builds on previous efforts that targeted the use of subgrid treatments to improve the accuracy of control rod representation, presenting three additional applications of subgrid treatments with the goal of reducing the computational burden of simulations. These subgrid applications include treatment of spacer grids, thermal feedback, and axial reflector material representation. With these approaches, a single method of characteristics (MOC) plane can contain several different materials axially that are represented explicitly via subgrids on the coarse mesh finite difference (CMFD) mesh but are axially homogenized on the MOC mesh. This allows for a substantial reduction in the number of MOC planes needed in the calculation through the introduction of an approximate treatment, particularly with regard to the self-shielded cross sections and MOC-informed radial current coupling coefficients in CMFD.
Several test problems ranging from single rod to quarter core are used to assess the solution accuracy and performance of these various subgrid representations. Overall, the accuracy of the approximations seems very reasonable, with extremely small differences in eigenvalue observed and maximum pin power errors in the 0.5% to 1.0% range. Several cases show substantial value in the compromise between accuracy and computational performance. Others highlight the new computational hurdles that future research will aim to resolve.