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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.
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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.
C. H. Reed, C. N. Henry, A. A. Usner
Nuclear Science and Engineering | Volume 30 | Number 3 | December 1967 | Pages 362-373
Technical Paper | doi.org/10.13182/NSE67-A18399
Articles are hosted by Taylor and Francis Online.
Asymptotic decay constants for pulse-induced “thermalized” neutron fields have been measured for graphite cubical assemblies having geometric bucklings varying from 9.30 × 10–4 cm–2 to 13.44 × 10–3 cm–2. A value of 700 μ sec was observed to be a sufficient time after the neutron pulse to identify and evaluate fundamental-mode decay in the smallest system included in the above interval of buckling. Values of the infinite-medium neutron lifetime –1 “Fick’slaw” diffusion coefficient D0, as well as the so-called “diffusion-cooling” coefficient C, were obtained from least-squares fits to the experimental α/ρ vs B2/ρ2 data and are mutually consistent and stable over a large interval of B2 and in good agreement with theory. The existence of a well-defined negative FB6 term has been verified. An “effective” higher-mode decay of (3570 ± 80)sec–1, independent of system buckling, was obtained and is consistent with the concept of a continuum lying above a critical limit for fundamental-mode decay. An apparent critical limit (v ∑ t)min has been identified in the interval 2392 sec–1 < (v ∑ t)min < 2648 sec–1 which corresponds to the interval of buckling 13.44 × 10–3 cm–2 to 16.53 × 10–3 cm–2.