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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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Latest News
Sandia and Aeva evaluate intrusion detection system
Sandia National Laboratories is collaborating with the California-based Aeva Technologies, a developer of next-generation sensing and perception systems, on the development of technology for strengthening security at U.S. nuclear reactor sites.
Maxence Maillot, Jean Tommasi, Gérald Rimpault
Nuclear Science and Engineering | Volume 184 | Number 2 | October 2016 | Pages 190-207
Technical Paper | doi.org/10.13182/NSE16-5
Articles are hosted by Taylor and Francis Online.
In neutron chain systems with material symmetries, various k-eigenvalues of the neutron balance equation beyond the dominant one may be degenerated. As shown in a companion paper, the power iteration method can be used to compute higher eigenfunctions in symmetric systems, provided that the global problem is partitioned into symmetry class–related lower-sized problems with appropriate boundary conditions. Those boundary conditions have been implemented in the diffusion solver of the ERANOS code system in rectangular geometry and within the framework of a discontinuous Galerkin spatial approximation of the multigroup discrete ordinates transport equation in the SNATCH solver. Numerical results in homogeneous geometry are provided for verification purposes, as well as the first eigenfunctions of the Takeda benchmarks. Finally, the transport effect on the first flux harmonics for an industrial-sized reactor ZPPR-18 is discussed.