Compilation, evaluation, and dissemination of covariances in microscopic nuclear reaction data

Accurate uncertainty and covariance in microscopic nuclear reaction data (e.g., resonance parameters, cross sections) are needed for safe and economic design of new reactors. Evaluators of nuclear data libraries are trying to collect, evaluate, and distribute uncertainty and covariance information to satisfy those needs. To support these tasks, the IAEA Nuclear Data Section (NDS) is actively developing the experimental data library, appropriate evaluation methods and dissemination tools that will be reviewed in this paper.