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.
Division Spotlight
Decommissioning & Environmental Sciences
The mission of the Decommissioning and Environmental Sciences (DES) Division is to promote the development and use of those skills and technologies associated with the use of nuclear energy and the optimal management and stewardship of the environment, sustainable development, decommissioning, remediation, reutilization, and long-term surveillance and maintenance of nuclear-related installations, and sites. The target audience for this effort is the membership of the Division, the Society, and the public at large.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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
Apr 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
May 2025
Nuclear Technology
April 2025
Fusion Science and Technology
Latest News
First astatine-labeled compound shipped in the U.S.
The Department of Energy’s National Isotope Development Center (NIDC) on March 31 announced the successful long-distance shipment in the United States of a biologically active compound labeled with the medical radioisotope astatine-211 (At-211). Because previous shipments have included only the “bare” isotope, the NIDC has described the development as “unleashing medical innovation.”
Richard Sanchez, Li Mao, Simone Santandrea
Nuclear Science and Engineering | Volume 140 | Number 1 | January 2002 | Pages 23-50
Technical Paper | doi.org/10.13182/NSE140-23
Articles are hosted by Taylor and Francis Online.
Boundary conditions are an essential part of the approximations used in the numerical solution of the transport equation. The collision probability and the characteristic methods are considered, and exact and approximated tracking methods to be used in the implementation of geometrical motions and albedo conditions are analyzed. The analysis of the exact boundary-condition treatment is carried out for finite domains and infinite lattices, where periodic trajectories must be used. Albedo-like boundary conditions may be used to approximate exact geometrical motions via spatially piecewise constant and either piecewise constant or discrete angular approximations for the boundary fluxes. We also have examined angular product quadrature formulas and shown that the recently proposed Bickley-Naylor quadratures do not respect particle conservation in the presence of anisotropy of scattering. Numerical examples show that the approximated albedo-type boundary method converges toward the results obtained with the exact boundary treatment. However, because of problems related to the multigroup implementation, numerical extra burden in group iterations prevents the efficient use of approximated boundary conditions for multigroup calculations. Nevertheless, this method remains a candidate of choice for use in multidomain calculations via interface boundary fluxes.
