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Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
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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.
Guanyi Wang, Qingzi Zhu, Mamoru Ishii (Purdue Univ)
Proceedings | Advances in Thermal Hydraulics 2018 | Orlando, FL, November 11-15, 2018 | Pages 77-87
As a critical closure equation to the two-fluid model and an important tool to characterize the two-phase flow interfacial transport, interfacial area transport equation (IATE) was formulated by taking various physical mechanisms causing interface area change into account. To fulfill the dynamic prediction advantage of the IATE and further replace the flow-regime-based constitutive relations, the IATE model should be validated by transition data to ensure the model reliability and robustness. Air-water experiments are performed in bubbly to slug transitions flows in a 200×10 mm narrow rectangular duct. Four-sensor conductivity probes are used to measure the local void fraction, interfacial area concentration, and bubble velocity at three axial locations. The sectional void fraction distribution changes significantly with the flow developing. Flow conditions with similar area-averaged void fraction but different superficial mixture velocities are compared, and it is found that the superficial liquid velocity obviously affect the interfacial area concentration. The measured data with developing spatial distribution would be useful to benchmark and improve the current two-phase flow models used in CFD. Besides, the two-group IATE model for narrow rectangular channel is evaluated using the collected data. The average relative error for the interfacial area concentration prediction is 11.4%, but the group II IAC are overestimated for most flow conditions. To realize better prediction in bubbly to slug transition flows, improvement of the current IATE model is required.
