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
Isotopes & Radiation
Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
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.
James F. Jackson, William E. Kastenberg
Nuclear Science and Engineering | Volume 42 | Number 3 | December 1970 | Pages 278-294
Technical Paper | doi.org/10.13182/NSE70-A21218
Articles are hosted by Taylor and Francis Online.
A numerical investigation of space-time effects in the dynamic behavior of fast breeder reactors is presented. The basic approach is to compare results from point kinetics and time-dependent diffusion theory. The accuracy of point kinetics is determined for different approximations to the shape function used in calculating the initiating reactivity and feedback coefficients. Several space-dependent feedback models are studied. The importance of considering spatial effects that arise from two sources is shown. The first type consists of those induced by local reactivity perturbations. Usually, these can be adequately accounted for through the proper selection of a shape function. For example, it is found that when calculating rapid, localized ramp insertions, a good choice is the flux shape at prompt critical. The second type consists of those induced by feedback with strong space dependence. Spatial effects of this type are shown to be difficult to cope with when applying point kinetics.