The Global Assessment of Nuclear Data, GANDR

The GANDR project was initiated by the IAEA in 2001 with several ambitious goals, including the eventual provision of assistance to data experts in the planning of new measurements. We describe a hardware and software system developed in support of this project, now in operation in the IAEA Nuclear Data Section. A specific design goal of the system is to be able to track, in complete detail, the impact of new experiments on the uncertainties and correlations of 91000 independent parameters. This number is sufficient, for example, to describe the broad, energy-dependent features of most cross section types for 130 different target materials. Applications of GANDR to date have utilized experimental data from the EXFOR database. EXFOR includes only the diagonal elements of the data covariance matrix (variances), and often the supplied variances describe only the statistical part of the data uncertainty, so the GANDR system offer several options for modifying and supplementing the available experimental uncertainties.