ESTABLISHMENT OF AN APPLICABLE VERSION OFTHE CIAU METHODOLOGY

摘要

The best-estimate calculation results fromcomplex system codes are affected byapproximations that are un-predictable without theuse of computational tools that account for thevarious sources of uncertainty. The Code with (thecapability of) Internal Assessment of Uncertainty(CIAU) has been proposed by the University of Pisato realize the integration between a qualified bestestimatethermal-hydraulic system code and asuitable uncertainty methodology and to supplyproper uncertainty bands each time a nuclear powerplant transient scenario is calculated. In the frame ofa cooperation with The Pennsylvania StateUniversity, the CIAU code has been recentlyextended to evaluate the uncertainty of coupled 3-Dneutronics/thermal-hydraulics calculations. Theresult of this effort is CIAU-TN. The derivation ofthe methodology and the adopted qualificationprocesses ("internal" and "external") are describedin the paper. Uncertainty, Accuracy, Best-estimate,UMAE, CIAU.