ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Explore membership for yourself or for your organization.
Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
Standards Program
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!
Latest Magazine Issues
Jul 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
August 2025
Nuclear Technology
Fusion Science and Technology
July 2025
Latest News
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.
Cheikh M. Diop, Mireille Coste-Delclaux, Sébastien Lahaye
Nuclear Science and Engineering | Volume 170 | Number 1 | January 2012 | Pages 87-97
Technical Note | doi.org/10.13182/NSE10-94TN
Articles are hosted by Taylor and Francis Online.
In the frame of neutral-particle (neutron, gamma) transport, the uncertainty propagation calculation regarding the uncertainties on cross sections is often carried out without explicitly taking into account their probabilistic distribution. We investigate a new uncertainty propagation formalism where the cross-section uncertainty distributions are represented by probability tables.This technical note develops this approach for the steady-state slowing-down equation without upscattering and in an infinite medium. This work is based on a deterministic multiband formalism that takes into account multilevel probability tables for cross sections. The first level represents the variation of cross sections versus lethargy (or energy) in each group of the multigroup lethargy mesh and thus corresponds to the classical cross-section probability tables. The higher levels represent the uncertainties on each step of the first-level cross-section probability table. This method is validated against a Monte Carlo calculation in a case of neutron slowing down in a 238U-hydrogen homogeneous mixture, showing fully consistent numerical results. The main interest of the deterministic multilevel multiband formalism is that it gives not only the mean value and the variance but also a probabilistic distribution of the fluxes.In the near future, we plan to investigate more deeply the robustness of this new approach in relation to high values of cross-section uncertainties and to introduce cross-section uncertainty correlations as well. Meanwhile, the promise of this work is its extension to the general transport steady-state equation solved by the discrete ordinates (SN) or Monte Carlo methods.