Optimization method for the design of hexagonal fuel assemblies
2015 (English)In: Annals of Nuclear Energy, ISSN 0306-4549, E-ISSN 1873-2100, Vol. 75, 498-506 p.Article in journal (Refereed) Published
The duct wall and inter-assembly gap make up 5–15% of the volume of a typical fast reactor core and these components have a profound impact on the system neutron economy. In this paper, a methodology for the design of optimum hexagonal fuel assembly geometries was developed. For each nuclear reactor core made up of ducted assemblies there exists a unique optimum solution of duct wall thickness and inter-assembly gap, where these components have the minimum impact on the core neutron balance while adhering to applicable structural constraints. The assembly duct wall must maintain its structural integrity and intended function while being exposed to a harsh environment of pressure, temperature and neutron fluence causing elastic and inelastic deflections and swelling. Analytical expressions, appli- cable to any internally pressurized hexagonal structure, were defined for the peak stress and elastic wall deflection. Detailed analysis of fuel assembly duct designs requires finite element code analysis, radial bowing analysis codes and the full temperature, flux and stress distribution over the lifetime of the assembly in the core to accurately estimate creep deformation. The simple analytical methodology pre- sented in this paper can provide a good initial guess for an optimal geometry to be iteratively improved and refined using more advanced codes and methods.
Place, publisher, year, edition, pages
2015. Vol. 75, 498-506 p.
IdentifiersURN: urn:nbn:se:uu:diva-232494DOI: 10.1016/j.anucene.2014.08.060ISI: 000347493400061OAI: oai:DiVA.org:uu-232494DiVA: diva2:748440