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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.
Stanley E. Turner
Nuclear Science and Engineering | Volume 151 | Number 3 | November 2005 | Pages 344-347
Technical Note | doi.org/10.13182/NSE05-A2553
Articles are hosted by Taylor and Francis Online.
In recent years, neutron attenuation measurements have demonstrated that neutron absorber panels with discrete boron carbide particles are less effective in neutron absorption than equivalent homogenous absorber panels. The penalty observed in these attenuation measurements with thermal neutrons has been assumed to apply to the criticality analysis of fuel storage cells, without regard to the very significant difference in the neutron spectrum involved. Furthermore, the attenuation measurements are made with a collimated beam of thermalized neutrons impinging perpendicularly on the absorber panel, whereas in fuel storage cells, the neutrons are nearly isotropic and impinge on the panel at all angles. In an effort to understand the phenomena involved and to more accurately determine the effect on criticality safety analyses, calculations were made with the MCNP code, which is capable of explicitly describing discrete B4C particles of various mean size. Results of these calculations, described herein, show that neutron attenuation measurements are only weakly related to criticality analysis and that the penalty seen in attenuation measurements does not apply and should not be directly applied in criticality analyses.