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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
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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
Take steps on SNF and HLW disposal
Matt Bowen
With a new administration and Congress, it is time once again to ponder what will happen—if anything—on U.S. spent nuclear fuel and high-level waste management policy over the next few years. One element of the forthcoming discussion seems clear: The executive and legislative branches are eager to talk about recycling commercial SNF. Whatever the merits of doing so, it does not obviate the need for one or more facilities for disposal of remaining long-lived radionuclides. For that reason, making progress on U.S. disposal capabilities remains urgent, lest the associated radionuclide inventories simply be left for future generations to deal with.
In March, Rick Perry, who was secretary of energy during President Trump’s first administration, observed that during his tenure at the Department of Energy it became clear to him that any plan to move SNF “required some practical consent of the receiving state and local community.”1
W. A. Haller, R. W. Perkins, J. M. Nielsen
Nuclear Technology | Volume 3 | Number 7 | July 1967 | Pages 436-443
Technical Paper and Note | doi.org/10.13182/NT67-A27842
Articles are hosted by Taylor and Francis Online.
An instrumental method has been devised and tested for the direct measurement of 137Cs in fission product mixtures. The method is based on beta-gamma coincidence counting, and involves beta counting of the mixture in a liquid or plastic scintillator while simultaneously measuring the gamma-ray spectrum with a NaI(Tl) detector-multichannel analyzer arrangement. Cesium-137 is unique among the long-lived fission products in that its decay (actually its 137mBa daughter, T1/2 = 2.8 min) does not involve a prompt beta-gamma coincidence. The 137Cs is then measured from a noncoincidence gamma spectrum with comparatively little interference from the other fission products. The method is not directly applicable to recently irradiated fuels but has been applied to the quantitative measurement of 137Cs in 8-month-, 1.3-year- and 2.0-year-old material with standard deviations of about 3, 0.8, and 0.7%, respectively.
