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Conference Spotlight
2025 ANS Winter Conference & Expo
November 8–12, 2025
Washington, DC|Washington Hilton
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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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Latest News
Nuclear News 40 Under 40: The wait is over
Following the enthusiastic response from the nuclear community in 2024 for the inaugural NN 40 Under 40, the Nuclear News team knew we had to take up the difficult task in 2025 of turning it into an annual event—though there was plenty of uncertainty as to how the community would receive a second iteration this year. That uncertainty was unfounded, clearly, as the tight-knit nuclear community embraced the chance to celebrate its up-and-coming generation of scientists, engineers, and policy makers who are working to grow the influence of this oft-misunderstood technology.
Alain Hébert, Mireille Coste
Nuclear Science and Engineering | Volume 142 | Number 3 | November 2002 | Pages 245-257
Technical Paper | doi.org/10.13182/NSE01-56
Articles are hosted by Taylor and Francis Online.
As part of the self-shielding model used in the APOLLO2 lattice code, probability tables are required to compute self-shielded cross sections for coarse energy groups (typically with 99 or 172 groups). This paper describes the replacement of the multiband tables (typically with 51 subgroups) with moment-based tables in release 2.5 of APOLLO2. An improved Ribon method is proposed to compute moment-based probability tables, allowing important savings in CPU resources while maintaining the accuracy of the self-shielding algorithm. Finally, a validation is presented where the absorption rates obtained with each of these techniques are compared with exact values obtained using a fine-group elastic slowing-down calculation in the resolved energy domain. Other results, relative to the Rowland's benchmark and to three assembly production cases, are also presented.