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Young Members Group
The Young Members Group works to encourage and enable all young professional members to be actively involved in the efforts and endeavors of the Society at all levels (Professional Divisions, ANS Governance, Local Sections, etc.) as they transition from the role of a student to the role of a professional. It sponsors non-technical workshops and meetings that provide professional development and networking opportunities for young professionals, collaborates with other Divisions and Groups in developing technical and non-technical content for topical and national meetings, encourages its members to participate in the activities of the Groups and Divisions that are closely related to their professional interests as well as in their local sections, introduces young members to the rules and governance structure of the Society, and nominates young professionals for awards and leadership opportunities available to members.
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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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.
M. M. R. Williams
Nuclear Science and Engineering | Volume 141 | Number 1 | May 2002 | Pages 13-31
Technical Paper | doi.org/10.13182/NSE02-A2263
Articles are hosted by Taylor and Francis Online.
A method has been developed for calculating the probability distribution of the multiplication factor in a system in which the fissile or absorbing elements are randomly distributed across the core and can have random material properties. It has practical applications to the storage of radioactive waste in drums in which fissile material is stored in a background matrix. The procedure is based upon the source-sink method of heterogeneous reactors developed by Feinberg, Galanin, Horning and Stewart in which the fuel element or absorber is replaced by a point sink of thermal neutrons and a point source of fast neutrons. The positions and material properties are sampled from a random distribution and a probability distribution is built up for the multiplication factor keff. Calculations are made for spheres in a cubic system and probability distributions, mean values and variances are obtained for 1, 2, 3, 5, 10 and 25 spheres in both water and graphite moderated systems. Some interesting fine structure is found in the probability distributions which is attributed to preferred symmetric groupings of the spheres in the lattice. We also examine the effect of small random movements of the spheres about their mean positions and in particular study the effect of anisotropy of motion, i.e. perpendicular to the plane and in the plane, on the mean value of the multiplication factor and the associated probability distributions. Some experimental results obtained by Lloyd on reactivity changes in random lattices are examined and qualitative agreement is obtained. A convenient form of the three dimensional Greens function for a rectangular box is developed which is especially useful for numerical purposes due to its rapid convergence properties.
