Taming the Crud Problem: A Utility Perspective

Models of crud and oxide deposition were developed to allow prediction of the magnitude of crud and oxide deposits on nuclear fuel cladding. Adjustable parameters for each model were quantified through regression analysis using eddy-current measured crud/oxide thickness for the dependent variable and selected calculated thermal-hydraulic coefficients for independent variables. Insights gained during model development together with the newly acquired ability to predict crud thickness have enabled us to redesign the fuel lattice so as to minimize the adverse impact of crud deposition. The lattice redesign reclaims the benefit of cost efficient ring-type loadings without challenging plant operations and fuel pin integrity