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The division was organized to promote the advancement of knowledge of the use of particle accelerator technologies for nuclear and other applications. It focuses on production of neutrons and other particles, utilization of these particles for scientific or industrial purposes, such as the production or destruction of radionuclides significant to energy, medicine, defense or other endeavors, as well as imaging and diagnostics.
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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.
Anil Kumar
Nuclear Science and Engineering | Volume 82 | Number 3 | December 1982 | Pages 354-358
Technical Note | doi.org/10.13182/NSE82-A19396
Articles are hosted by Taylor and Francis Online.
In the considerations of recriticality of molten fuel assemblies, the presence of bubbles in the fuel plays an important role. In such a situation, there are two opposing contributions to reactivity from (a) the phenomenon of neutron streaming in bubbles (negative contribution) and (b) the phenomenon of changing neutron self-multiplication in the fuel (positive contribution). It is not possible to accurately calculate the individual reactivity contributions of the two phenomena using multidimensional transport theory or Monte Carlo codes. A simple diffusion theory expression given by Nicholson and Goldsmith for estimating reactivity contribution due to neutron streaming alone has been used extensively. As a part of the present contribution, first an attempt has been made to improve the applicability of the Nicholson-Goldsmith work by expressing extrapolation length in terms of the root-mean-square free path in the assembly. It is found that the application of the Trombay criticality formula, particularly its “modified Wigner rational variant,” leads to an expression for bubble reactivity worth, due to neutron streaming alone, that yields the closest agreement with the bubble worth values computed from the two-dimensional transport theory code TWOTRAN and the Monte Carlo code KENO.