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
Aug 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
Fusion Science and Technology
August 2025
Latest News
Powering the future: How the DOE is fueling nuclear fuel cycle research and development
As global interest in nuclear energy surges, the United States must remain at the forefront of research and development to ensure national energy security, advance nuclear technologies, and promote international cooperation on safety and nonproliferation. A crucial step in achieving this is analyzing how funding and resources are allocated to better understand how to direct future research and development. The Department of Energy has spearheaded this effort by funding hundreds of research projects across the country through the Nuclear Energy University Program (NEUP). This initiative has empowered dozens of universities to collaborate toward a nuclear-friendly future.
R. Roy
Nuclear Science and Engineering | Volume 123 | Number 3 | July 1996 | Pages 358-368
Technical Paper | doi.org/10.13182/NSE96-A24199
Articles are hosted by Taylor and Francis Online.
The integral transport equation is solved in square unit cells by assuming the existence of a fundamental mode. The equations governing the Bn method are given without making the small buckling approximation. First, the angular flux is factorized into two parts: a periodic microscopic fine-structure flux and a macroscopic form with no angular dependence. The macroscopic form only depends on a buckling vector with a given orientation. The critical buckling norm, along with the corresponding fine-structure flux, is obtained using collision probability calculations that are repeated until criticality is achieved. The procedure allows the periodic or reflective boundary conditions of the unit cell to be taken into account using closed-form contributions obtained from the cyclic tracking technique. Numerical results are presented for one-group heterogeneous cell problems with isotropic and linearly anisotropic scattering kernels, some of which include void regions.