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Division Spotlight
Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
Meeting Spotlight
2025 ANS Annual Conference
June 15–18, 2025
Chicago, IL|Chicago Marriott Downtown
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!
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Latest News
NRC v. Texas: Supreme Court weighs challenge to NRC authority in spent fuel storage case
The State of Texas has not one but two ongoing federal court challenges to the Nuclear Regulatory Commission that could, if successful, turn decades of NRC regulations, precedent, and case law on its head.
Jerry B. F. Champlin
Nuclear Technology | Volume 8 | Number 3 | March 1970 | Pages 283-289
Paper | Analysis | doi.org/10.13182/NT70-A28675
Articles are hosted by Taylor and Francis Online.
The void space in a variety of objects can be obtained by a neutron activation method utilizing the normal argon content in the air filling the pores and voids of such samples. The activation reaction used is 40Ar(n, γ)41Ar which has a cross section of 0.63 b. Argon-41 decays by beta emission with a half-life of 1.85 h to the stable isotope of potassium, 41K. If the quantity of air in a sealed container is known, the air can be used as an activation “foil” to estimate the total flux seen by the sample while in the reactor. After standard air volumes have been evaluated, porous solids containing air can be analyzed for void space if placed under the same conditions of geometry and efficiency and the activity acquired used as a measure of the total air present relative to a standard. It is possible to use this technique with substances for which the porosity (void space/bulk volume) is difficult to measure in other ways.
