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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.
David Regnier, Olivier Litaize, Olivier Serot
Nuclear Science and Engineering | Volume 174 | Number 1 | May 2013 | Pages 103-108
Technical Note | doi.org/10.13182/NSE12-12
Articles are hosted by Taylor and Francis Online.
The average total prompt neutron multiplicity [nu with overbar] of 252Cf spontaneous fission is investigated as a function of the total kinetic energy TKE and the mass split of the fragments through the code FIFRELIN. This Monte Carlo device, already described in a previous work, aims at simulating the neutron evaporation from fission fragments. The observables and TKE and the light fragment mass AL are recorded from a sample of 107 fission events. The analyzed results show a value for the inverse of the slope [[partial differential][nu with overbar](TKE)/[partial differential]TKE]-1 equal to -11.0 MeV/n. In addition to this, the average number of neutrons per fission [nu with overbar](TKE, AL) is determined for every possible TKE and AL. For every fragment mass ratio, differences in behavior between [nu with overbar](TKE, AL) versus TKE and [nu with overbar](TKE) with no discrimination made with regard to AL are observed. Those differences are explained by the TKE dependency of fission yield. The approximation consisting of ignoring this TKE dependency of mass yield when calculating the [nu with overbar](TKE) slope is discussed. We estimate that such a calculation could lead to a significant bias on the absolute value of [partial differential][nu with overbar](TKE)/[partial differential]TKE and could explain the discrepancies between calculations found in the literature.
