tailieunhanh - Reassessment of gadolinium odd isotopes neutron cross sections: scientific motivations and sensitivity-uncertainty analysis on LWR fuel assembly criticality calculations

This article shows how the most recent gadolinium cross sections evaluations appear inadequate to provide accurate criticality calculations for a system with gadolinium fuel pins. In this article, a sensitivity and uncertainty analysis (S/U) has been performed to investigate the effect of gadolinium odd isotopes nuclear cross sections data on the multiplication factor of some LWR fuel assemblies. | Reassessment of gadolinium odd isotopes neutron cross sections scientific motivations and sensitivity-uncertainty analysis on LWR fuel assembly criticality calculations EPJ Nuclear Sci. Technol. 3 21 2017 Nuclear Sciences F. Rocchi et al. published by EDP Sciences 2017 amp Technologies DOI epjn 2017015 Available online at http REGULAR ARTICLE Reassessment of gadolinium odd isotopes neutron cross sections scientific motivations and sensitivity-uncertainty analysis on LWR fuel assembly criticality calculations Federico Rocchi1 Antonio Guglielmelli1 Donato Maurizio Castelluccio1 and Cristian Massimi2 3 1 ENEA Italian National Agency for New Technologies Energy and Sustainable Economic Development Centro Ricerche E. Clementel Via Martiri di Monte Sole 4 40129 Bologna Italy 2 Department of Physics and Astronomy University of Bologna Via Irnerio 46 40126 Bologna Italy 3 INFN Via Irnerio 46 40126 Bologna Italy Received 8 November 2016 Received in final form 11 May 2017 Accepted 2 June 2017 Abstract. Gadolinium odd isotopes cross sections are crucial in assessing the neutronic performance and safety features of a light water reactor LWR core. Accurate evaluations of the neutron capture behavior of gadolinium burnable poisons are necessary for a precise estimation of the economic gain due to the extension of fuel life the residual reactivity penalty at the end of life and the reactivity peak for partially spent fuel for the criticality safety analysis of Spent Fuel Pools. Nevertheless present gadolinium odd isotopes neutron cross sections are somehow dated and poorly investigated in the high sensitivity thermal energy region and are available with an uncertainty which is too high in comparison to the present day typical industrial standards and needs. This article shows how the most recent gadolinium cross sections evaluations appear inadequate to provide accurate criticality calculations for a system with gadolinium fuel pins. In this article a .