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This division promotes the development and timely introduction of fusion energy as a sustainable energy source with favorable economic, environmental, and safety attributes. The division cooperates with other organizations on common issues of multidisciplinary fusion science and technology, conducts professional meetings, and disseminates technical information in support of these goals. Members focus on the assessment and resolution of critical developmental issues for practical fusion energy applications.
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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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.
R. K. Lane, L. W. Nordheim, J. B. Sampson
Nuclear Science and Engineering | Volume 14 | Number 4 | December 1962 | Pages 390-396
Technical Paper | doi.org/10.13182/NSE62-A26247
Articles are hosted by Taylor and Francis Online.
The problem of resonance absorption is investigated for materials in which the absorber is lumped in small grains imbedded in a matrix of moderator. The point of departure is to take the grains themselves as the fundamental elements in heterogeneous geometry. It is important to treat correctly the mutual shielding between the grains, that is, the Dancoff correction. Introduction of this correction solves immediately the case of macroscopically homogeneous assemblies. The result can be expressed in terms of “shielded” cross sections for the lumped absorber. Utilization of this concept permits also the treatment of additional macroscopic heterogeneities. Existing calculational methods can be employed if the macroscopic heterogeneities are treated with the help of the equivalence relations, and this procedure permits an adequate comparison between the grain structured and homogeneous compounds. Numerical examples are given in Section IV. The average shielding is nearly linear in the grain size. For grains of ThO2 in a graphite matrix, the reduction is about 15% for grains of 0.06 cm diam. On the other hand, the temperature derivative of the resonance integral is increased slightly, particularly at higher temperatures. One can, therefore, either maintain the Doppler coefficient of reactivity with a reduced resonance absorption or increase the Doppler coefficient for the same resonance absorption.