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ANS Student Conference 2025
April 3–5, 2025
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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.
Mark L. Williams, Harish Manohara
Nuclear Science and Engineering | Volume 111 | Number 4 | August 1992 | Pages 345-367
Technical Paper | doi.org/10.13182/NSE92-A15483
Articles are hosted by Taylor and Francis Online.
Contributons are the special particles distributed among a general population that generate the response observed on a specified detector. Contributon slowing-down theory describes the transfer of the response through space and energy as it is carried by contributons from the source to the detector. The response flow through space-energy and space-lethargy obeys the contributon slowing-down equation, which expresses conservation of contributons. A four-dimensional vector field is introduced to identify space and energy channels followed by the contributons, and is used to define response flow lines through space-lethargy. Numerical expressions are presented to compute the response current and slowing-down density that define the components of the response flow field. It is shown how these variables can be used to perform energy channel theory analysis of a particle transport problem. The method is applied to two realistic problems. The first determines contributon transport channels followed through space-energy by fission neutrons produced in a pressurized water reactor as they travel from the core to the reactor cavity region, where they activate surveillance dosimeters. The second examines the response transfer from a nuclear weapon burst as it is carried by contributons through space-lethargy channels in air to detectors located at some distance from ground-zero.