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
Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
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.
C. B. Mills, G. I. Bell
Nuclear Science and Engineering | Volume 12 | Number 4 | April 1962 | Pages 469-473
Technical Paper | doi.org/10.13182/NSE62-A26093
Articles are hosted by Taylor and Francis Online.
In this paper we present calculated critical masses of homogeneous water-moderated assemblies containing low enrichment uranium. The calculations were made using the multigroup DSN code with eighteen energy groups. Effective absorption cross sections for U238 were computed with the “infinite mass” and “narrow resonance” approximations. The calculations have been compared with various experiments and rather good agreement was found. The results are presented as a parametric survey for U235/U atom ratios from 0.014 to 0.300 and for all H/U235 ratios for which criticality is possible. The decrease in critical radius with an infinite water reflector is also shown. We find that a bare homogeneous system with U235/U < 0.010 cannot be made critical at any H/U235 ratio.
