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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.
Tsuguyuki Kobayashi
Nuclear Technology | Volume 177 | Number 2 | February 2012 | Pages 231-244
Technical Paper | Reprocessing | doi.org/10.13182/NT12-A13368
Articles are hosted by Taylor and Francis Online.
A simple procedure to simulate the important kinetic features of counter-current processes in pulsed columns has been developed. The overall mass transfer coefficient was simplified to be constant along the column, and the stripping of Pu4+ by hydroxylamine is assumed to be instantaneous to avoid complex reaction rate calculations. The number of calculation cells can be determined by making calculations with an increasing number of cells until its influence becomes small enough. The validity of these simplifications was confirmed by comparing the calculation results with a wide range of measured data from extraction and stripping as well as Pu partition tests with laboratory, engineering, and pilot scale columns. This procedure is intended for use in a conceptual design study of a future fast breeder reactor (FBR) reprocessing plant. An example of its application in a flow sheet calculation was demonstrated, where a coextraction process of U and Pu was simulated to find the conditions to obtain a solution with Pu/(U + Pu) ratio being 30% from a typical feed of FBR spent fuel solution.