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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.
K. D. Kirby, R. A. Karam
Nuclear Science and Engineering | Volume 59 | Number 3 | March 1976 | Pages 215-230
Technical Paper | doi.org/10.13182/NSE76-A26820
Articles are hosted by Taylor and Francis Online.
Effective resonance cross sections used in the analysis of heterogeneous reactors have generally been obtained through the use of equivalence theory and/or integral transport theory. One fundamentally restrictive assumption common to equivalence theory and most integral transport methods is the flat-source approximation. The assessment of this approximation was recently completed and comprised the following: 1. comparison of the broad-group cross sections of 238U in the resolved resonance region using. a. the flat-source approximation b. the exact source distribution c. the rational approximation with a Levine-type factor 2. comparisons in (1) for three types of reactors. a. typical zero power reactor (ZPR) assembly b. liquid-metal fast breeder reactor commercial power station c. light-water power reactor. The main conclusion was that even though there were significant differences between the exactly calculated escape probabilities and those calculated with the flat-source approximation, additional differences between the general energy-dependent reciprocity and the energy-independent (but often erroneously applied as energy-dependent) reciprocity relation almost completely compensated for the error in the flat-source escape probabilities. Due to this unusual and somewhat unexpected compensating effect, the effective capture cross sections of 238U in the resolved resonance region, generated by the three methods stated above, were essentially the same.
