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
2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
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
May 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
June 2024
Nuclear Technology
Fusion Science and Technology
Latest News
Proving DRACO will deliver
The United States is now closer than it has been in over five decades to launching the first nuclear thermal rocket into space, thanks to DRACO—the Demonstration Rocket for Agile Cislunar Orbit.
S. Dulla, P. Ravetto, M. M. Rostagno, G. Bianchini, M. Carta, A. D'Angelo
Nuclear Science and Engineering | Volume 149 | Number 1 | January 2005 | Pages 88-100
Technical Paper | doi.org/10.13182/NSE149-88
Articles are hosted by Taylor and Francis Online.
The paper considers some physical aspects of the neutron space kinetics of critical and source-driven subcritical systems. The possibility of introducing some indicators to qualify the spatial nature of neutronic transients is investigated. It is shown theoretically and then proved by numerical examples that the separation of the eigenvalues of the mathematical operator defining the problem can be taken as a good indicator of the importance of space effects in time-dependent conditions. To obtain good physical insight into the phenomena, paradigmatically simple configurations are considered, and whenever possible, a fully analytical approach is used. The presented results evidence the limits of applicability of classic simplified models for transient analyses, such as point kinetics. In a second part, the paper considers the open problem of the choice of the weighting function to be used either for the generation of the kinetic parameters of pointlike models or for the exploitation of quasi-static procedures, analyzing comparatively the effect of different options on the results of transient calculations.