ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
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Division Spotlight
Isotopes & Radiation
Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
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.
Odmaa Sambuu, Toru Obara
Nuclear Science and Engineering | Volume 177 | Number 1 | May 2014 | Pages 97-110
Technical Note | doi.org/10.13182/NSE13-22
Articles are hosted by Taylor and Francis Online.
In the past decade, greater emphasis has been placed in nuclear reactor design on passive systems for the removal of decay heat. This study focuses on the passive safety feature of decay heat removal in modular high-temperature gas-cooled reactors (HTGRs). The availability of this feature depends largely on reactor dimensions, power, and initial core temperature. It is assumed that the initial temperatures of fuel, graphite matrix, and coolant are the same, and so are represented by the initial core temperature, which is uniformly distributed throughout the core. However, little is known in general about the relationships among the parameters mentioned above or on the ability of the core to passively reject decay heat. To obtain a general understanding of the relationship of those parameters in HTGRs, analyses were performed, estimating the effects of initial core and soil temperatures and of the presence of structural materials on the maximum core temperature, allowable power, and size. Appropriate sizes were evaluated for reactors with given powers having various maximum power densities and operating at different initial core temperatures. Criticality and burnup analyses for the proposed reactors were performed, and it was found that all reactors with 20 wt% of uranium enrichment can be critical for over 16 years of operation.