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Division Spotlight
Isotopes & Radiation
Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
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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Ariz. governor vetoes “fast track” bill for nuclear
Gov. Katie Hobbs put the brakes on legislation that would have eliminated some of Arizona’s regulations and oversight of small modular reactors, technology that is largely under consideration by data centers and heavy industrial power users.
Mohamed Sawan, Robert W. Conn
Nuclear Science and Engineering | Volume 54 | Number 2 | June 1974 | Pages 127-142
Technical Paper | doi.org/10.13182/NSE74-A23401
Articles are hosted by Taylor and Francis Online.
Methods for the analysis of neutron pulses slowing down in heavy media are presented. The Green’s function coupling method is reviewed and the application of a prompt-jump approximation to pulses slowing down in heavy media is discussed. In this paper, these methods are applied in particular to the analysis of the lead slowing down time spectrometer (LSDTS) and the application of this device to nondestructive fissile material assay (NDA). The effects of pulse width, spectrometer size, higher order spatial modes, and lead cross-section data on the calibration curve (t versus 1/√E, the dieaway curve N(t) versus t, and the time-dependent spectrum of the LSDTS are reported. For NDA, the assay of fresh light-water reactor (LWR), plutonium recycle, and fast reactor fuel pins, as well as spent LWR fuel pins, is studied. The effects of self shielding and pulse width on the discrimination capability of the LSDTS are assessed. Two energy ranges (27.6 to 43.6 eV and 10.3 to 16.3 eV) are proposed for the assay of mixed-oxide fuel where discrimination between 235U and 239Pu is required. An error analysis of NDA with lead spectrometers that includes the calibration surfaces which occur in the assay of mixed-oxide fuel pins is given.
