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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.
P. A. Pizzica, H. H. Hummel
Nuclear Technology | Volume 56 | Number 2 | February 1982 | Pages 313-321
Nuclear Safety | doi.org/10.13182/NT82-A32860
Articles are hosted by Taylor and Francis Online.
Various loss-of-flow cases have been calculated for a commercial-sized liquid-metal fast breeder reactor. Particular attention has been paid to the development of loss-of-flow-driven transient-overpower (LOF-TOP) conditions. In such conditions, it is crucial to consider when an initial cladding breach might occur in LOF-TOP pins and over what length of time the initial cladding breach might extend in fuel pins failing under burst pressure. This study shows that the neutronic energy deposition in transient calculations including LOF-TOP pin failures can increase substantially compared to a calculation excluding such LOF-TOP failures in two ways. First, there will be an increase if there is no extension of an initial cladding failure in LOF-TOP pins or if there is a relatively long delay in the extension. Secondly, when, in applying a fuel melt fraction criterion for pin failure, the same melt fraction is specified for failure extension as for initial failure, which implies a certain delay time for failure extension, there will be an increase in the energy deposition compared to the case without any LOF-TOP failures only when the specified fuel melt fraction becomes very large. However, even in the case with the largest failure melt fraction, there will be no increase in energy deposition when a rapid enough failure extension is assumed. These calculations make a number of very conservative assumptions. The purpose of the study is not to provide a best estimate of accident conditions but to show how quickly an initial cladding breach must extend in such conservative calculations if it is to limit the increase in neutronic energy deposition.