About this Journal Submit a Manuscript Table of Contents
Science and Technology of Nuclear Installations
Volume 2013 (2013), Article ID 437409, 10 pages
http://dx.doi.org/10.1155/2013/437409
Research Article

Uncertainty Analysis of Light Water Reactor Fuel Lattices

1Department of Physics and Nuclear Engineering, Technical University of Catalonia, 08034 Barcelona, Spain
2Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802, USA

Received 20 August 2012; Accepted 18 November 2012

Academic Editor: Carlo Parisi

Copyright © 2013 C. Arenas et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The study explored the calculation of uncertainty based on available cross-section covariance data and computational tool on fuel lattice levels, which included pin cell and the fuel assembly models. Uncertainty variations due to temperatures changes and different fuel compositions are the main focus of this analysis. Selected assemblies and unit pin cells were analyzed according to the OECD LWR UAM benchmark specifications. Criticality and uncertainty analysis were performed using TSUNAMI-2D sequence in SCALE 6.1. It was found that uncertainties increase with increasing temperature, while decreases. This increase in the uncertainty is due to the increase in sensitivity of the largest contributing reaction of uncertainty, namely, the neutron capture reaction 238U(n, γ) due to the Doppler broadening. In addition, three types (UOX, MOX, and UOX-Gd2O3) of fuel material compositions were analyzed. A remarkable increase in uncertainty in was observed for the case of MOX fuel. The increase in uncertainty of in MOX fuel was nearly twice the corresponding value in UOX fuel. The neutron-nuclide reaction of 238U, mainly inelastic scattering (n, n′), contributed the most to the uncertainties in the MOX fuel, shifting the neutron spectrum to higher energy compared to the UOX fuel.