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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.
Per Seltborg, Jan Wallenius
Nuclear Science and Engineering | Volume 154 | Number 2 | October 2006 | Pages 202-214
Technical Paper | doi.org/10.13182/NSE06-A2626
Articles are hosted by Taylor and Francis Online.
The distribution of actinides in the core of an accelerator-driven system loaded with plutonium, americium, and curium has been studied in order to optimize the proton source efficiency *. The optimization of * was performed by keeping some important characteristics of the system, e.g., the radial power profile and the reactivity of the core, constant. One of the basic assumptions of the study, that the magnitude of * is sensitive primarily to the composition of actinides in the inner part of the core, whereas only marginally to that in the outer part, has been confirmed. It has been shown that the odd-N nuclides (those nuclides with an even number of neutrons) in general and 241Am and 244Cm in particular have favorable properties with respect to improving * if they are placed in the innermost part of the core. The underlying reason for this phenomenon is that the energy spectrum of the source neutrons in the inner part of the core is harder than that of the average fission neutrons. Moreover, it has been shown that loading the inner part of the core with only curium increases * by ~7%. Plutonium, on the other hand, in particular high-quality plutonium consisting mainly of 239Pu and 241Pu, was found to be a comparatively source inefficient element and is preferably located in the outer part of the core. The differences in * are due to combined effects from relative changes in the average fission and capture cross sections and in the average fission neutron yield.