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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.
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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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.
John G. Kollas and Allan F. Henry
Nuclear Science and Engineering | Volume 60 | Number 4 | August 1976 | Pages 464-471
Technical Note | doi.org/10.13182/NSE76-A26907
Articles are hosted by Taylor and Francis Online.
A method for obtaining homogenized group-diffusion-theory parameters for heterogeneous nodes (fuel regions plus control elements plus structure) in slab geometry is described. The parameters obtained reproduce exactly the neutron leakage and the integrated reaction rates of the node when it becomes part of a reactor. However, for asymmetric nodes they depend on the fluxes and currents at the surfaces of the node. The sensitivity of this dependence is examined for a one-group model, and numerical examples are given to illustrate that for symmetric nodes, the equivalent parameters are indeed exact and independent of conditions outside the node. For unsymmetric nodes, it is shown that using a set of parameters that is an average of two sets of “exact parameters,” one appropriate to large values of current-to-flux ratio at one of the nodal surfaces and the other appropriate to small values, still yields quite accurate results. For both cases comparisons with results obtained using standard flux-weighted parameters are made.