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
Nuclear Criticality Safety
NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
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
Argonne’s METL gears up to test more sodium fast reactor components
Argonne National Laboratory has successfully swapped out an aging cold trap in the sodium test loop called METL (Mechanisms Engineering Test Loop), the Department of Energy announced April 23. The upgrade is the first of its kind in the United States in more than 30 years, according to the DOE, and will help test components and operations for the sodium-cooled fast reactors being developed now.
Adimir dos Santos, Ricardo Diniz
Nuclear Science and Engineering | Volume 178 | Number 4 | December 2014 | Pages 459-478
Technical Paper | doi.org/10.13182/NSE14-10
Articles are hosted by Taylor and Francis Online.
The evaluation of the experiments of the effective delayed neutron parameters and reactivity performed in the IPEN/MB-01 research reactor facility has been successfully accomplished. The evaluated data are of very good quality and fulfill the requirements of a benchmark. The recently released MCNP6 together with the ENDF/B-VII.1, JENDL-4.0, JEFF-3.1.1, ENDF/B-VII.0, and JENDL-3.3 nuclear data libraries has been employed to calculate the effective delayed neutron parameters adopting the benchmark model of the IPEN/MB-01 reactor available in the International Handbook of Reactor Physics Benchmark Experiments. The analysis reveals that all these nuclear data libraries produced satisfactory results for βeff, βeff/Λ, and Λ. The same cannot be said for determining the reactivity using the Inhour equation. It was shown that there is a clear tendency to increase the deviation with the absolute value of the reactivity for negative periods. Only JENDL-3.3 and JEFF-3.1.1 produced results that are inside the 3σ range of the benchmark value uncertainty. Specifically for the case of ENDF/B-VII.1, a good part of this discrepancy is due to the decay constant of the first group of delayed neutrons, which is overestimated according to the experimental value measured in the IPEN/MB-01 reactor.
