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Division Spotlight
Accelerator Applications
The division was organized to promote the advancement of knowledge of the use of particle accelerator technologies for nuclear and other applications. It focuses on production of neutrons and other particles, utilization of these particles for scientific or industrial purposes, such as the production or destruction of radionuclides significant to energy, medicine, defense or other endeavors, as well as imaging and diagnostics.
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!
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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.
Rene Sanchez, David Loaiza, Robert Kimpland, David Hayes, Charlene Cappiello, Mark Chadwick
Nuclear Science and Engineering | Volume 158 | Number 1 | January 2008 | Pages 1-14
Technical Paper | doi.org/10.13182/NSE08-A2734
Articles are hosted by Taylor and Francis Online.
A series of critical-mass experiments using a 6-kg neptunium sphere was performed on the Planet vertical-assembly machine at Los Alamos National Laboratory (LANL). The purpose of the experiments was to obtain a better estimate of the critical mass of 237Np. The configurations that were studied included surrounding the neptunium sphere with highly enriched uranium (HEU) shells as well as reflecting it with iron and polyethylene. An additional experiment using a 4.5-kg -phase plutonium sphere surrounded with HEU was performed to demonstrate how well the computer transport code and the existing cross-section data for uranium and plutonium could reproduce the experiment. For some of the configurations, the prompt-neutron decay constants at delayed critical were measured. These experiments provided an integral measurement of the cross sections for 237Np in the fast-energy and possibly in the intermediate-energy regions. The measured keff from these experiments was compared with the calculated keff from the Monte Carlo N-Particle (MCNP) transport code using ENDF/B-V and ENDF/B-VI and cross-section data evaluated by the Nuclear Theory and Applications group (T-16) at LANL. In all the neptunium experiments, the calculated keff values based on ENDF/B-VI data were ~1% lower than the experimental keff. After adjusting the cross sections for neptunium and 235U to match the bare neptunium/HEU experiment as well as Godiva keff criticality and spectra indexes, the MCNP code yielded a value of 57 ± 4 kg for the bare critical mass of 237Np.
