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
2025 ANS Winter Conference & Expo
November 8–12, 2025
Washington, DC|Washington Hilton
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
Oct 2025
Jul 2025
Latest Journal Issues
Nuclear Science and Engineering
November 2025
Nuclear Technology
Fusion Science and Technology
Latest News
Ho Nieh, TVA board members, and nuclear fuel recycling bill head to Senate floor
Nieh
Ho Nieh, the Trump administration’s nominee to be a member of the Nuclear Regulatory Commission, and four new board members of the Tennessee Valley Authority were approved in a vote today by the Senate Environment and Public Works Committee and head to the Senate floor for a final vote.
The committee also voted to advance to the Senate floor the Nuclear REFUEL Act of 2025 (S. 2082), which would smooth the regulatory pathway for recycling used nuclear fuel.
President Donald nominated Nieh on July 30 to serve as NRC commissioner for the remainder of a term set to expire June 30, 2029, which was held by former NRC commissioner Chris Hanson, who Trump fired in June.
M. R. Mendelson
Nuclear Science and Engineering | Volume 28 | Number 1 | April 1967 | Pages 127-132
Technical Paper | doi.org/10.13182/NSE67-A18675
Articles are hosted by Taylor and Francis Online.
The sensitivity of three thermal-energy model problems to anisotropic scattering was investigated by comparing double P5 solutions with P3 and P1 scattering expansions. Results indicate that P3 scattering effects can be significant in the calculation of absorption rates in certain sensitive plane-geometry configurations. Monte Carlo calculations were also performed for one of these problems, using two different anisotropic scattering representations: the transport approximation; and a “histogram” kernel, which match the first two and four Legendre moments of the scattering kernel, respectively. The transport approximation was found to give discrepancies of eight to nine percent in thermal absorption rates, and it is concluded that this scattering representation can lead to serious errors in Monte Carlo calculations.
