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
Nuclear Criticality Safety
NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
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.
Harvey J. Amster, M. Jahed Djomehri
Nuclear Science and Engineering | Volume 60 | Number 2 | June 1976 | Pages 131-142
Technical Paper | doi.org/10.13182/NSE76-A26869
Articles are hosted by Taylor and Francis Online.
Successive solutions to two coupled integral equations provide the expected statistical error of any Monte Carlo calculation in which the external source is specified and the “score” resulting from each collision has a known probability distribution. Each equation can be transformed into a differential-integro form that is adjoint to the transport equation. This result agrees with the stochastic theory of Bell for those special situations described by both theories. The coupled integral equations in the Monte Carlo theory of Coveyou et al. have other adjoint properties because they describe physically different quantities. In the present theory, the first equation (for the expected value), but not the second (for the expected squared value), can readily be understood in terms of Selengut's general interpretation of adjoint solutions. The principal aim of this work is to provide a method for determining in advance whether or not development of a contemplated Monte Carlo program would be worthwhile. Any of the approximations commonly applied to the transport equation can be used. Some examples are worked out by diffusion theory, interpreted, and tested for accuracy.