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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.
P. Benoist
Nuclear Science and Engineering | Volume 34 | Number 3 | December 1968 | Pages 285-307
Technical Paper | doi.org/10.13182/NSE68-3
Articles are hosted by Taylor and Francis Online.
In a previous publication by Benoist, a simple and general formulation of the streaming effect in lattices was established which defines the diffusion coefficients by a suitable weighting of the mean-free-paths of the various media; this formulation introduced special types of collision probabilities initially calculated by an iteration technique. However, it appeared better to work with a closed formulation as the series of angular correlation terms evidenced a very slow convergence, especially for large channels. This approach requires the solution of the Boltzmann equation with particular types of sources. This solution is shown to be equivalent to the treatment of a cell in terms of some fictitious reaction. rates which are defined. The problem is essentially analogous to the calculation of the thermal utilization factor, an analogy that has been exploited as far as possible. Finally, by an adjustment on the corresponding void channel system, the treatment of fueled channels is made and a new method is proposed for the direct treatment of the latter case. The new expressions obtained for the diffusion coefficients are very simple and the numerical results obtained with them agree very well with reference calculations made by a variational method which is also exposed. Various auxiliary corrections are studied, and, finally, formulae for practical utilization are given in the Appendix.