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.
Explore membership for yourself or for your organization.
Conference Spotlight
2026 Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
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
Nov 2025
Jul 2025
Latest Journal Issues
Nuclear Science and Engineering
December 2025
Nuclear Technology
Fusion Science and Technology
November 2025
Latest News
Nuclear power’s new rule book: Managing uncertainty in efficiency, safety, and independence
The U.S. nuclear industry is standing at its most volatile regulatory moment yet—one that will shape the trajectory and the safety of the industry for decades to come. Recent judicial, legislative, and executive actions are rewriting the rules governing the licensing and regulation of nuclear power reactors. Although these changes are intended to promote and accelerate the deployment of new nuclear energy technologies, the collision of multiple legal shifts—occurring simultaneously and intersecting with profound technological uncertainties—is overwhelming the Nuclear Regulatory Commission and threatening to destabilize investor and industry expectations.
J. Nilsson and R. Sandlin
Nuclear Science and Engineering | Volume 23 | Number 3 | November 1965 | Pages 224-233
Technical Paper | doi.org/10.13182/NSE65-A19555
Articles are hosted by Taylor and Francis Online.
An investigation has been carried out concerning the transmission of thermal and fast neutrons in air-filled annular ducts. A calculational model to predict the air-gap flux is developed and fitted to the results from foil-activation experiments in a Fe-D2 O configuration, the duct length being about half a meter and the annular air gaps varying from 0.5 to 2.0 cm. It is based upon the condition that the flux is theoretically and experimentally divided into uncollided and collided components for both thermal and fast neutrons. The model may be applied to most of the straight annular ducts that occur in reactor shielding, but it is especially designed for the problems met with in short ducts.
