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Division Spotlight
Thermal Hydraulics
The division provides a forum for focused technical dialogue on thermal hydraulic technology in the nuclear industry. Specifically, this will include heat transfer and fluid mechanics involved in the utilization of nuclear energy. It is intended to attract the highest quality of theoretical and experimental work to ANS, including research on basic phenomena and application to nuclear system design.
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.
D. C. Wade, R. G. Bucher
Nuclear Science and Engineering | Volume 64 | Number 2 | October 1977 | Pages 517-538
Technical Paper | doi.org/10.13182/NSE77-A27387
Articles are hosted by Taylor and Francis Online.
Flux weighting for the generation of broad-group cross sections is designed to preserve eigenvalue, flux spectrum, and reaction rates; however, it will not preserve adjoint spectrum and reactivity worths. Bilinear (flux-adjoint) weighting preserves all of the above quantities except reaction rates. Bilinear weighting also makes the eigenvalue of the broad-group calculation less sensitive to distortions of the spectrum away from the fundamental mode over which the cross sections were collapsed than is the case when flux weighting is used. A series of 29- and 11-group numerical tests has been made to assess the size of errors (relative to a fine-group standard) in eigenvalue, reaction rate ratios, isotopic worth components, and spectral shapes resulting from the use of the two energy collapse procedures. The errors in adjoint spectrum and calculated worth of scattering materials are found to be large when flux weighting is used.