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Modernizing I&C for operations and maintenance, one phase at a time
The two reactors at Dominion Energy’s Surry plant are among the oldest in the U.S. nuclear fleet. Yet when the plant celebrated its 50th anniversary in 2023, staff could raise a toast to the future. Surry was one of the first plants to file a subsequent license renewal (SLR) application, and in May 2021, it became official: the plant was licensed to operate for a full 80 years, extending its reactors’ lifespans into 2052 and 2053.
Hyun Chul Lee, Jae Man Noh, Hyung Kook Joo, Deokjung Lee, Thomas J. Downar
Nuclear Science and Engineering | Volume 156 | Number 1 | May 2007 | Pages 74-85
Technical Paper | doi.org/10.13182/NSE06-32
Articles are hosted by Taylor and Francis Online.
The purpose of this paper is to present the Fourier convergence analysis of four methods for performing two-dimensional/one-dimensional (2-D/1-D) coupling to solve neutron diffusion eigenvalue problems (EVPs). The four methods differ principally in the manner of using the interface currents or node average fluxes to perform the 2-D/1-D coupling. Method A uses net currents, method B employs partial currents, method C uses a current correction factor, and method D uses an analytic expression for the axial net currents. In a previous paper, we analyzed the convergence behavior of these methods for the 2-D/1-D coupling of the fixed source problem (FSP). In this paper, the convergence performance of these methods is analyzed for the EVP using a one-group neutron diffusion EVP in a homogeneous infinite slab geometry. Among the four methods, method A diverges for small mesh sizes as it did in the FSP, whereas the other methods are stable regardless of the mesh size. The spectral radii of methods C and D are identical while the latter had a smaller spectral radius than the former in an FSP. The spectral radii of methods C and D are smaller than that of method B in the range of practical mesh size. The spectral radii approach one for all the methods as the mesh size increases, while in the FSP the spectral radii of method B approached a finite positive value and those of the other methods approached zero. For practical applications, method C has several advantages over the other methods and is the preferred 2-D/1-D coupling method for EVPs.