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Title: An effective thermal-hydraulics methodology for prismatic core HTGR and VHTR

Conference ·
OSTI ID:22105957
 [1];  [1]
  1. Inst. for Space and Nuclear Power Studies, Univ. of New Mexico, Albuquerque, NM (United States)

Optimizing the performance and design of a prismatic core HTGR or VHTR requires a full core thermal-hydraulics analysis. Owing to the complexity and massive core structure, such analysis requires extensive and massively parallelized computation capabilities and a relatively long time (weeks to months) to complete. These demanding requirements are not due to the 3-D simulation of heat conduction in the annular core of the reactor, but rather the 3-D computational fluid dynamics (CFD) simulation of the helium gas flow in the 10-m long cooling channels in the 102 hexagonal fuel elements and the axial graphite reflector blocks in the core. This paper applies and examines the effectiveness of using a 1-D simulation of the helium flow in the core coolant channels, coupled to a 3-D simulation of the heat conduction in the graphite and fuel compacts, to perform thermal-hydraulics analysis of a hexagonal fuel element and of a 1/6 full core. This methodology employs typical cosine and constant axial power profiles and an applicable convective heat transfer correlation for the helium flow in the coolant channels. The correlation has recently been validated for a 10 m tall, single channel fuel module and shown to significantly reduce the computation time and memory requirements without compromising the accuracy of the calculations. The fidelity and accuracy of the present results for a hexagonal fuel element are verified by comparing them to those of a full 3-D numerical analysis. In addition to the temperature fields, results compare the computation time and number of numerical grid elements for implementing the two numerical simulation methods. The results of the thermal-hydraulics analysis of a 1/6 full core with the simplified methodology are also presented. All performed analysis accounts for the temperature dependent properties of helium, graphite in the reactor core and reflector blocks and the TRISO particle fuel compacts. (authors)

Research Organization:
American Nuclear Society, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
OSTI ID:
22105957
Resource Relation:
Conference: ICAPP '12: 2012 International Congress on Advances in Nuclear Power Plants, Chicago, IL (United States), 24-28 Jun 2012; Other Information: Country of input: France; 9 refs.; Related Information: In: Proceedings of the 2012 International Congress on Advances in Nuclear Power Plants - ICAPP '12| 2799 p.
Country of Publication:
United States
Language:
English