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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.
M. Z. Youssef, A. Kumar, M. Abdou, M. Nakagawa, K. Kosako, Y. Oyama, T. Nakamura
Fusion Science and Technology | Volume 19 | Number 3 | May 1991 | Pages 1891-1902
Neutronic | Proceedings of the Ninth Topical Meeting on the Technology of Fusion Energy (Oak Brook, Illinois, October 7-11, 1990) | doi.org/10.13182/FST91-A29619
Articles are hosted by Taylor and Francis Online.
Effort in Phase IIC of the US/JAERI Collaborative Program on Fusion Neutronics was focused on performing integral experiments and post analyses on blankets that include the actual hetergeneities found in several blanket designs. Two geometrical arrangements were considered, namely multilayers of Li2O and beryllium in an edge-on, horizontally alternating configuration for a front depth of 30 cm, followed by the Li2O breeding zone (Be edge-on, BEO, experiment), and vertical water coolant channels arrangement in which one is placed behind the first wall and two other channels (width of 0.5 cm each) are placed at depths of 10 and 30 cm from the first wall (WCC experiment). The objectives are to experimentally verify the enhancement in tritium production in the first experiment and to examine the accuracy of predicting tritium production and other reaction rates around these heterogeneities in the two experiments. In the BOE system, it was shown that, with the zonal method to measure tritium production from natural lithium (Tn), the calculated-to-measured values (C/E) are 0.95 − 1.05 (JAERI) and 0.98 − 0.9 (U.S.), which is consistent with the results obtained in other Phases of the Program. In the WCC experiment, there is a noticeable change in C/E values for T6 near the coolant channels where steep gradients in T6 production are observed. The C/E values obtained with the Li-foils to measure T6 are better than those obtained by the Li-glass method. As for T7, calculations and measurements by NE213 method are within ± 15% in JAERI's analysis, but larger values (∼ 20–25%) are obtained in the U.S. analysis. Around heterogeneities, the prediction accuracy for T7 is better than that for T6. In both experiments, the prediction accuracy for high-threshold reactions [(e.g. 93Nb(n,2n)] is within ± 10% as obtained by both Monte Carlo and Sn codes, however, it was shown that the 58Ni(n,2n) cross-section of ENDF/B-V should be increased by 25–30% at high incident neutron energies to give better C/E values.