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2026 ANS Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
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DOE signs two more OTAs in Reactor Pilot Program
This week, the Department of Energy has finalized two new other transaction agreements (OTAs) with participating companies in its Reactor Pilot Program, which aims to get one or two fast-tracked reactors on line by July 4 of this year. Those companies are Terrestrial Energy and Oklo.
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.