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
Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
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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Nuclear Science and Engineering
August 2025
Nuclear Technology
July 2025
Fusion Science and Technology
Latest News
Supreme Court rules against Texas in interim storage case
The Supreme Court voted 6–3 against Texas and a group of landowners today in a case involving the Nuclear Regulatory Commission’s licensing of a consolidated interim storage facility for spent nuclear fuel, reversing a decision by the 5th Circuit Court of Appeals to grant the state and landowners Fasken Land and Minerals (Fasken) standing to challenge the license.
B. Becker, A. Weltz, J. A. Kulisek, J. Thompson, N. Thompson, Y. Danon
Nuclear Science and Engineering | Volume 175 | Number 2 | October 2013 | Pages 124-134
Technical Paper | doi.org/10.13182/NSE12-66
Articles are hosted by Taylor and Francis Online.
The use of a lead slowing-down spectrometer (LSDS) is considered as a possible option for nondestructive assay of fissile material of used nuclear fuel. The primary objective is to quantify fissile isotopes, particularly 239Pu and 235U, via a direct measurement distinguishing them through their characteristic fission spectra in the LSDS. In this paper, we present several assay measurements performed at the Rensselaer Polytechnic Institute (RPI) to support ongoing feasibility studies of the method and to provide benchmark experiments for Monte Carlo calculations of the assay system. A fresh uranium oxide fuel rod from the RPI Walthousen Reactor Critical Facility, a 239Pu-Be source, and several highly enriched 235U disks were assayed in the LSDS. The characteristic fission spectra were measured with 238U and 232Th threshold fission chambers, which are primarily sensitive to fission neutrons with energies above the threshold. Despite the constant neutron and gamma background from the Pu-Be source and the intense interrogation neutron flux, the LSDS system was able to measure the characteristic 235U and 239Pu responses. All measurements were compared to Monte Carlo simulations complementing previous modeling-based studies. It is shown that the available simulation tools and models are well suited to simulate the assay. An absolute calibration technique of the LSDS, which is required to perform quantitative measurements of the assayed fissile materials, is presented.
