Nuclear Data and Fuel/Assembly Manufacturing Uncertainties Analysis and Preliminary Validation of SUACL

Abstract

As the sensitivity and uncertainty analysis of nuclear system can provide more confident bounds for the Best-estimate Prediction used to assess the performance and safety of nuclear plant, the uncertainty and sensitivity analysis has been a component of analysis of nuclear system. Both the cross section uncertainty and the uncertainty of parameters of fuel/assembly manufacturing are analyzed in this paper. All results of SUACL were found in accordance with the results of reference codes.238U and 235U play an important role in determining the uncertainty of Keff in TMI-1 cell. The uncertainty of Keff in MOX is mainly affected by 239Pu and 238U. It is obvious that the uncertainty mostly depends on the covariance library and insensitivities to cross section library. The uncertainties based on the covariance library obtained from ENDF/B-VII.1 differ from the result of JENDL4.0, which verified the relationship of covariance matrix and the uncertainty of cross section. And the parameters of fuel/assembly manufacturing uncertainty are comparable to uncertainty of some cross section, especially the 235U concentration, clad thickness. The uncertainty analysis of these parameters is of great significance to evaluate the parameter of actual cell and help to improve the model simulated. More attentions need paid to improve the accuracy of the parameters analysis talked in the paper.