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
2026 ANS Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
Latest Magazine Issues
Mar 2026
Jan 2026
Latest Journal Issues
Nuclear Science and Engineering
April 2026
Nuclear Technology
February 2026
Fusion Science and Technology
Latest News
2025 annual assessments out for U.S. reactors
The Nuclear Regulatory Commission has released its 2025 annual performance assessments of the country’s 95 operating commercial nuclear reactors. And of the 95 reactors, all but five earned the highest marks.
Nuclear power plant assessments can fall under one of five categories: Licensee Response, Regulatory Response, Degraded Cornerstone, Degraded Performance, and Unacceptable Performance. Ninety reactors fell under Licensee Response, the highest performance category in safety and security. Plants that achieve this level of performance are subject to a Reactor Oversight Process (ROP) baseline inspection.
B. Akherraz, C. Fedon-Magnaud, J. J. Lautard, R. Sanchez
Nuclear Science and Engineering | Volume 120 | Number 3 | July 1995 | Pages 187-198
Technical Paper | doi.org/10.13182/NSE95-A24118
Articles are hosted by Taylor and Francis Online.
Three approaches are presented to treat anisotropic scattering in neutron transport. The approaches are based on the even-odd-parity flux formalism and yield three different second-order equations for the even-parity flux. The first one is based on the total elimination of the odd-parity flux of the second-order equation. In the other two approaches, anisotropic scattering contributions are homogenized and incorporated into the collision term. The numerical solutions of these equations are implemented in the CRONOS code for pressurized water reactor core calculations and are done with a finite element spatial approximation and the discrete ordinates methods (SN) for the angular variable. Numerical results are presented for critical problems (keff) in x-y geometry. Comparisons with the APOLL02 assembly code show the accuracy and the efficiency of the proposed algorithms.