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
Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
Meeting Spotlight
2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
September 2024
Nuclear Technology
Fusion Science and Technology
August 2024
Latest News
Nuclear new build procurement considerations
It may seem counterintuitive, but the best time to enhance the ability to support operations and maintenance for a new plant is before construction starts. This is one of many lessons learned by the currently operating nuclear fleet. As construction and startup of many nuclear facilities was completed, it quickly became evident that the ability to efficiently support operations and maintenance was limited. Most of the information necessary to establish and manage procurement of spare and replacement items, maintenance, and configuration of the facilities was unavailable and had to be gathered on a case-by-case, “on-demand” basis. Absence of necessary information and the associated challenges resulted in the need for staff augmentation and multiyear-long projects to develop equipment bills of material and maintenance programs and to perform technical evaluations for the huge quantities of spare and replacement items being requested.
Tomasz Błeński
Nuclear Science and Engineering | Volume 87 | Number 1 | May 1984 | Pages 84-96
Technical Note | doi.org/10.13182/NSE84-A17449
Articles are hosted by Taylor and Francis Online.
The extrapolation distance in the cylindrical Milne problem (“black” cylinder immersed in a homogeneous, infinite, isotropically scattering and absorbing medium) is calculated in one- and two-group approximations. The method used consists of asymptotic expansions in 1/R and R (R being the radius of the cylinder) for large and small R, respectively, and of a variational method for R = O(1), R measured in mean-free-paths. The numerical results are given for two cases in the one-group (c = 0.90 and c = 0.95) and for two cases in the two-group approximation (both for κ = 1). The results show convergence of the methods and sufficient accuracy of the applied numerical procedures. This conclusion is confirmed by the comparison of the values of the extrapolation distance calculated by variational and asymptotic expansion formulas in regions of R, where both can be applied.