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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.
R. C. Lloyd, R. A. Libby, E. D. Clayton
Nuclear Science and Engineering | Volume 82 | Number 3 | December 1982 | Pages 325-331
Technical Paper | doi.org/10.13182/NSE82-A19393
Articles are hosted by Taylor and Francis Online.
Experiments were performed with a 122-cm-diam sphere to determine criticality of aqueous solutions of plutonium in a system having low-neutron leakage. The plutonium in the chemical form of Pu(NO3)4 had a 240Pu content of 2.52 wt%. The critical-sphere concentration obtained in this experiment was analyzed along with data from eight additional critical experiments to evaluate the minimum critical concentration for plutonium. The limiting critical concentration was determined to be 7.62 g Pu/ℓ, for Pu(NO3)4 without excess acid and 7.59 g Pu/ℓ for a 239Pu-water mixture. From these data, the Maxwellian-averaged thermal value of the number of fission neutrons emitted per neutron absorbed by 239Pu, eta, was determined to be 2.056 ± 0.037. The value at 2200 m/s is 2.100 ±0.041.
