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
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
Norway’s Halden reactor takes first step toward decommissioning
The government of Norway has granted the transfer of the Halden research reactor from the Institute for Energy Technology (IFE) to the state agency Norwegian Nuclear Decommissioning (NND). The 25-MWt Halden boiling water reactor operated from 1958 to 2018 and was used in the research of nuclear fuel, reactor internals, plant procedures and monitoring, and human factors.
T. D. Beynon, I. S. Grant
Nuclear Science and Engineering | Volume 23 | Number 4 | December 1965 | Pages 368-379
Technical Paper | doi.org/10.13182/NSE65-A21074
Articles are hosted by Taylor and Francis Online.
Double P/0 diffusion theory is shown to be a sufficiently accurate representation for calculating resonance absorption and its temperature coefficient. The theory is formulated to allow for non-uniform temperature distributions and spatial variation of neutron cross sections. It is applied to uranium rods in graphite-moderated reactors, assuming a parabolic fuel-temperature distribution. Volume and surface temperature coefficients for absorption are defined. The energy distributions of these coefficients in strongly absorbing resonances are shown to differ Significantly. It is found that the total volume coefficient exceeds the total surface coefficient by 15% at normal operating temperatures. At higher temperatures the total volume coefficient is larger by 5%. Rowlands' formula for the effective uniform temperature is shown to be reliable for calculating the resonance integral and the volume temperature coefficient, but not for the surface coefficient.
