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Organized to promote the advancement of knowledge in the use of nuclear science and technologies in the aerospace application. Specialized nuclear-based technologies and applications are needed to advance the state-of-the-art in aerospace design, engineering and operations to explore planetary bodies in our solar system and beyond, plus enhance the safety of air travel, especially high speed air travel. Areas of interest will include but are not limited to the creation of nuclear-based power and propulsion systems, multifunctional materials to protect humans and electronic components from atmospheric, space, and nuclear power system radiation, human factor strategies for the safety and reliable operation of nuclear power and propulsion plants by non-specialized personnel and more.
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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.
Xiaotian Li, Xiaowei Li, Li Shi, Zhengming Zhang, Shuyan He
Nuclear Technology | Volume 174 | Number 1 | April 2011 | Pages 29-40
Technical Paper | One-Phase Fluid Flow | doi.org/10.13182/NT11-A11677
Articles are hosted by Taylor and Francis Online.
The hot gas duct vessel (HGDV) is an important part of the high-temperature reactor-pebble-bed module (HTR-PM) primary loop pressure boundary system. It connects the reactor pressure vessel (RPV) and steam generator pressure vessel. Because the dimensions of the HGDV are smaller than those of the other two vessels, it is often considered the weakest of the three vessels. Therefore, the safety of the HGDV has become one of the most important issues in the design of the HTR-PM. In the present paper, a comprehensive safety analysis of the HGDV in the HTR-PM was performed with an emphasis on the structural features. The designs of the HGDV and the support system of the primary loop pressure boundary are first described. A preliminary safety analysis of the HGDV, including the stress calculations and leak-before-break (LBB) analysis, is then presented. The results show that the stress levels of the HGDV under various accidents have a safety margin of at least 55.3% compared with the stress limits specified in American Society of Mechanical Engineers code, and the stress intensity factor at the postulated flaw is less than the critical stress intensity factor. The LBB analysis indicated that the leak detection system is capable of detecting leaks caused by a postulated through-thickness crack in the HGDV before it reaches the critical size. Although the preliminary analysis has proved the safety of the HGDV, the consequences of a hypothetical HGDV double-ended break accident were also studied to further investigate the safety features of the HTR-PM. Several mitigation measures were employed based on the original design. The structural integrity of the support system, the reactor internals, and the containment under double-ended break accident were evaluated. The results show that these main structures could maintain integrity under the HGDV double-ended break accident.
