Abstract
Cross section evaluations in the resolved resonance region are based on formalisms derived from the R-matrix theory. As a result, the evaluations provide a set of resonance parameters that can be used to reproduce the experimental data reasonably well. The evaluated nuclear data are used in neutron transport calculations for the analysis and design of nuclear reactor systems, nuclear criticality safety analyses, etc. To achieve the desired accuracy on the nuclear system calculations, the questions frequently asked are how well the nuclear data are known and how the uncertainty in the nuclear data can be propagated into the final nuclear system results. There have been ongoing efforts at several research centers for generating data uncertainties in the resonance and high-energy regions. The biggest issue in relation to the covariance data is how good the calculated uncertainties are or whether the calculated uncertainties are in agreement with realistic uncertainties derived from an experimental nuclear system or nuclear benchmark. In this work an attempt is made to use two distinct and independently developed computer codes, CONRAD and SAMMY, to evaluate and generate covariance data in the resonance region. The verification study has been performed in support of the U.S. Nuclear Criticality Safety program (NCSP) as the NCSP is working to provide improved nuclear data files to support criticality safety analyses. The objective is to check the procedures and the methodologies used in the resonance region for covariance generation. The studies have been carried out using the 48Ti resolved resonance parameters.
