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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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Trinity Test at 80: American Nuclear Society CEO Craig Piercy reflects on the Manhattan Project
By Craig H. Piercy, CEO and Executive Director of the American Nuclear Society
Eighty years ago today, at exactly 5:29:45 a.m. local time* on July 16, 1945, the United States Army detonated the world’s first nuclear bomb in the Jornada del Muerto desert of southern New Mexico. The searing flash and thunderous shockwave marked the culmination of the Manhattan Project, a secret, three-year national effort to harness nuclear fission and hasten the end of the Second World War.
The Trinity test, overseen by Manhattan Project director Major General Leslie Groves and Los Alamos Laboratory director Dr. J. Robert Oppenheimer, was the final act of that race to build the atomic bomb. Hoisted atop a 100-foot steel tower, the plutonium implosion device, known as the Gadget, unleashed a blast equal to 21,000 tons of TNT and temperatures hotter than the center of the Sun.
From ten miles away, observers wearing darkened welder goggles, looked on in stunned silence. “We knew the world would not be the same,” recalled Oppenheimer.
N. Koyumdjieva, N. Janeva, K. Volev
Nuclear Science and Engineering | Volume 137 | Number 2 | February 2001 | Pages 194-205
Technical Paper | doi.org/10.13182/NSE01-A2185
Articles are hosted by Taylor and Francis Online.
There is a significant extension of the region of resolved resonances (RRR) for some nuclei to higher energies, and this has repercussions on the last updated versions of the evaluated nuclear data libraries. This energy extension covers intervals of the resonant cross-section structure, previously treated as an unresolved resonance region (URR). The reality of this situation provides an opportunity to verify a new statistical model of the resonant cross-section structure in the URR based on the characteristic function F of the R-matrix element distribution. For this purpose, the average cross sections and self-shielding factors obtained by the characteristic function model are compared with the corresponding quantities calculated by the Reich-Moore formalism of the R-matrix theory of nuclear reactions with the evaluated resonance parameters in the RRR. The ENDF/B-VI and JENDL 3.2 resolved resonance parameters of 56Fe and 238U are used for the cross-section calculations.
