A comprehensive validation approach using the RAVEN code

The RAVEN computer code, developed at the Idaho National Laboratory, is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is a multi-purpose probabilistic and uncertainty quantification platform, capable to communicate with any system code. A natural extension of the RAVEN capabilities is the implementation of an integrated validation methodology, involving several different metrics, that represent an evolution of the methods currently used in the field. The state-of-art validation approaches use neither exploration of the input space through sampling strategies, nor a comprehensive variety of metrics needed to interpret the code responses, with respect experimental data. The RAVEN code allows to address both these lacks. In the following sections, the employed methodology, and its application to the newer developed thermal-hydraulic code RELAP-7, is reported. The validation approach has been applied on an integral effect experiment, representing natural circulation, based on the activities performed by EG&G Idaho. Four different experiment configurations have been considered and nodalized.