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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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Hash Hashemian: Visionary leadership
As Dr. Hashem M. “Hash” Hashemian prepares to step into his term as President of the American Nuclear Society, he is clear that he wants to make the most of this unique moment.
A groundswell in public approval of nuclear is finding a home in growing governmental support that is backed by a tailwind of technological innovation. “Now is a good time to be in nuclear,” Hashemian said, as he explained the criticality of this moment and what he hoped to accomplish as president.
Nicholas W. Touran, John C. Lee
Nuclear Science and Engineering | Volume 179 | Number 1 | January 2015 | Pages 85-103
Technical Paper | doi.org/10.13182/NSE13-85
Articles are hosted by Taylor and Francis Online.
We developed a simulation tool that accelerates the evaluation of design changes on the equilibrium cycle of fast-spectrum nuclear reactors. Within the tool, an implicit equilibrium cycle search is accelerated by a modal expansion perturbation method that expands arbitrary flux perturbations on a large basis of λ-eigenmode harmonics. The harmonics are computed only at the reference state using Krylov subspace iterative methods, and substantial perturbations from this state are shown to be well approximated by computationally efficient algebraic expressions. The modal expansion method is coupled to the equilibrium method to produce the later-in-time response of each design perturbation, resulting in an explicit perturbation-accelerated equilibrium cycle method. Because the method determines the perturbed flux explicitly, a wide variety of core performance metrics may be tracked within optimization frameworks, including the performance of thermal hydraulics, fuel, economics, core mechanical, and transients. This capability strongly differentiates the method from traditional generalized perturbation theory approaches. The motivating end-use of the method is to evaluate objective functions in multidisciplinary optimization of advanced reactor designs, though many other applications are envisioned.