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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
2023 ANS Winter Conference and Expo
November 12–15, 2023
Washington, D.C.|Washington Hilton
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
Standard on fixed neutron absorbers in nuclear facilities outside reactors just issued (ANS-8.21)
ANSI/ANS-8.21-2023, Use of Fixed Neutron Absorbers in Nuclear Facilities Outside Reactors, has just been issued by the American Nuclear Society Standards Committee. The standard was approved by the American National Standards Institute (ANSI) on June 20, 2023, as a revision and consolidation of ANS-8.21-1995 (R2019) (withdrawn) (same title) and ANS-8.5-1996 (R2022) (withdrawn), Use of Borosilicate-Glass Raschig Rings as a Neutron Absorber in Solutions of Fissile Material. ANSI/ANS-8.21-2023 provides guidance for the use of neutron absorbers, including Raschig rings, as an integral part of nuclear facilities equipment, fissile material, or fuel components outside reactors, where such absorbers are credited to provide criticality safety control.
Tengfei Zhang, E. E. Lewis, M. A. Smith, W. S. Yang, Hongchun Wu
Nuclear Science and Engineering | Volume 186 | Number 2 | May 2017 | Pages 120-133
Technical Paper | doi.org/10.1080/00295639.2016.1273023
Articles are hosted by Taylor and Francis Online.
A two-dimensional/one-dimensional (2D/1D) variational nodal approach is presented for pressurized water reactor core calculations without fuel-moderator homogenization. A 2D/1D approximation to the within-group neutron transport equation is derived and converted to an even-parity form. The corresponding nodal functional is presented and discretized to obtain response matrix equations. Within the nodes, finite elements in the x-y plane and orthogonal functions in z are used to approximate the spatial flux distribution. On the radial interfaces, orthogonal polynomials are employed; on the axial interfaces, piecewise constants corresponding to the finite elements eliminate the interface homogenization that has been a challenge for method of characteristics (MOC)–based 2D/1D approximations. The angular discretization utilizes an even-parity integral method within the nodes, and low-order spherical harmonics (PN) on the axial interfaces. The x-y surfaces are treated with high-order PN combined with quasi-reflected interface conditions. The method is applied to the C5G7 benchmark problems and compared to Monte Carlo reference calculations.