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
Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
Meeting Spotlight
International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2025)
April 27–30, 2025
Denver, CO|The Westin Denver 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!
Latest Magazine Issues
Apr 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
June 2025
Nuclear Technology
Fusion Science and Technology
May 2025
Latest News
ANS designates Armour Research Foundation Reactor as Nuclear Historic Landmark
The American Nuclear Society presented the Illinois Institute of Technology with a plaque last week to officially designate the Armour Research Foundation Reactor a Nuclear Historic Landmark, following the Society’s decision to confer the status onto the reactor in September 2024.
P. F. Nichols
Nuclear Science and Engineering | Volume 17 | Number 1 | September 1963 | Pages 144-148
Technical Paper | doi.org/10.13182/NSE63-A17219
Articles are hosted by Taylor and Francis Online.
Reactivity measurements have been made in the Physical Constants Testing Reactor (PCTR) on a series of plutonium-aluminum rods with 0.65 in. diam and 31.00 in. long. The samples were contained in a cadmium cover during the measurements. The series of rods consisted of eight sets of two rods each. Two separate batches of plutonium with different isotopic compositions were used in the two rods within a set. The concentrations of plutonium in the alloys were adjusted in such a manner that (1) the two rods within a set differed effectively only in Pu240 content, and (2) the rod with the most Pu240 in one set had the same quantity of Pu240 as the rod with the least Pu240 in an adjacent set. The difference in reactivity measured between the rods in a set is the result of different resonance absorption rates in Pu240 in the two rods. The sensitivity of the reactor to epicadmium absorption in Pu240 was obtained by calibrating the system with three sets of rods that were all very nearly dilute in Pu240 concentration. The experimental data yield effective resonance integrals of Pu240 for the remaining rods relative to the dilute resonance integral. The value of the effective resonance integral for the rod with the highest concentration of Pu240 is a factor of about seven smaller than the dilute integral.
