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
Materials Science & Technology
The objectives of MSTD are: promote the advancement of materials science in Nuclear Science Technology; support the multidisciplines which constitute it; encourage research by providing a forum for the presentation, exchange, and documentation of relevant information; promote the interaction and communication among its members; and recognize and reward its members for significant contributions to the field of materials science in nuclear technology.
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
Norway’s Halden reactor takes first step toward decommissioning
The government of Norway has granted the transfer of the Halden research reactor from the Institute for Energy Technology (IFE) to the state agency Norwegian Nuclear Decommissioning (NND). The 25-MWt Halden boiling water reactor operated from 1958 to 2018 and was used in the research of nuclear fuel, reactor internals, plant procedures and monitoring, and human factors.
Matthew A. Gonzales, Brian C. Kiedrowski, Anil K. Prinja, Forrest B. Brown
Nuclear Science and Engineering | Volume 191 | Number 1 | July 2018 | Pages 1-45
Technical Paper | doi.org/10.1080/00295639.2018.1442546
Articles are hosted by Taylor and Francis Online.
The heavy-gas model with specific energy-dependent absorption cross sections is used to construct analytical, semi-analytical, and numerical free-gas scattering benchmarks for the neutron spectrum, effective multiplication factor k, and temperature coefficient in an infinite, homogeneous medium. The energy dependences considered are piecewise constant, constant plus inverse in energy, and piecewise linear. Analytic forms for k and in terms of hypergeometric functions are obtained for piecewise-constant absorption with two energy ranges and for constant-plus-inverse-in-energy absorption. Analogous semi-analytical integral expressions are obtained for piecewise-linear absorption with two energy ranges. Numerical solutions of a linear system are obtained for piecewise-constant and piecewise-linear absorption for greater than two energy ranges. The heavy-gas model solutions of k are compared with continuous-energy Monte Carlo calculations; the results converge to the heavy-gas model with increasing target mass ratio A, demonstrating the heavy-gas model’s utility as a verification benchmark.