The Best-estimate Methods – Uncertainty and Sensitivity Evaluation (BEMUSE) programme promoted by the Working Group on Accident Management and Analysis (WGAMA) and endorsed by the Committee on the Safety of Nuclear Installations (CSNI), represents an important step towards reliable application of high-quality best-estimate and uncertainty and sensitivity evaluation methods. The activity consists of two main steps, devoted to the application of these methods to a transient of type large-break loss-of-coolant accident (LB-LOCA).
Phase I is the presentation a priori of the uncertainty methodologies to be used by the participants and the (final) Phase VI is the synthesis of the results of the previous phases with conclusions and recommendations.
This report presents the results of Phase III, i.e. the phase devoted to uncertainty and sensitivity analysis applied to the LOFT L2-5 test. Ten (10) participants from nine organisations and seven countries took part in the exercise (not including an additional participation which arrived too late). Five thermal-hydraulic codes were used, sometimes with different versions. The end users for the results are expected to be industry, safety authorities and research laboratories.