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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
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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
First astatine-labeled compound shipped in the U.S.
The Department of Energy’s National Isotope Development Center (NIDC) on March 31 announced the successful long-distance shipment in the United States of a biologically active compound labeled with the medical radioisotope astatine-211 (At-211). Because previous shipments have included only the “bare” isotope, the NIDC has described the development as “unleashing medical innovation.”
Jeremy M. Osborn, Evans D. Kitcher, Jonathan D. Burns, Charles M. Folden, III, Sunil S. Chirayath
Nuclear Technology | Volume 201 | Number 1 | January 2018 | Pages 1-10
Technical Paper | doi.org/10.1080/00295450.2017.1401442
Articles are hosted by Taylor and Francis Online.
A nuclear forensics methodology has been developed that is capable of source attribution of separated weapons-grade plutonium in case of an interdiction. The methodology utilizes plutonium and contaminant fission product isotopes within the separated plutonium sample to determine the characteristics (reactor parameters) of the interdicted material. The reactor parameters of interest include source reactor type, fuel irradiation burnup, and time since irradiation. The MCNPX-2.7 radiation transport code was used to model reactor cores and perform neutronics simulations to estimate the resulting isotopes of irradiated UO2 fuel. The simulation results were used to create a reactor-dependent library of irradiated fuel isotope ratio values as a function of fuel burnup and time since irradiation. Ratios of intra-element isotopes (fission product or actinide) are used as characteristics to determine a combination of reactor parameters of interest that could have produced the interdicted sample. The isotopes selected for the attribution methodology development were based upon the initial criteria of isotope production yield in fuel and half-life. Subsequently, intra-element isotope ratios were formed with the criterion that the ratio must have a functional dependence on at least one of the reactor parameters of interest. The developed methodology compares the values of reactor-dependent intra-element isotope ratios in the library developed to the same ratios of the interdicted sample. A maximum likelihood calculation methodology was utilized to perform the aforementioned multiple intra-element isotope ratio comparison to produce a single metric to depict the result of the comparison. The methodology can predict the reactor type, fuel burnup, and time since irradiation of the sample by selecting the array of reactor-dependent intra-element isotope ratios that provides the maximum likelihood value. The methodology was tested with intra-element ratios of pseudo interdicted sample data and found to be viable for source attribution.
