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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.
Hans G. Kaper, Gary K. Leaf, Arthur J. Lindeman
Nuclear Science and Engineering | Volume 49 | Number 1 | September 1972 | Pages 27-48
Technical Paper | doi.org/10.13182/NSE72-A22525
Articles are hosted by Taylor and Francis Online.
This paper contains the results of detailed comparison studies of the efficiency of high order finite element approximations vs low order finite difference approximations, for the numerical solution of the static multigroup diffusion equation in two dimensions. The comparisons are based on the execution times for a Keff calculation with a prescribed precision for two particular computer programs— HOD (finite elements) and D ARC2D (finite differences). The calculations were performed for three different types of reactor configurations: a simple two-zone configuration with two energy groups, a multizone configuration [1000-MW(e) LMFBR mockup] with four energy groups, and a loosely coupled configuration with two energy groups. The conclusions are: 1. The use of high order approximation procedures based on finite element methods leads to substantial execution time savings and offers not just a viable alternative to the use of low order approximation procedures based on finite difference methods; it is, indeed, a significant advancement in computational capability. 2. With high order approximation procedures based on finite element methods it is possible to obtain, at reasonable cost, solutions to the multigroup diffusion equation which are sufficiently accurate that any errors can be attributed to either the diffusion theory approximation or other approximations in the reactor model, rather than to the numerical approximation procedure. 3. Solutions obtained with the finite element method provide as much accuracy in the flux inventories as in the multiplication factor.