Code structure uncertainties (model uncertainty) are a crucial source of uncertainty
quantification for thermal-hydraulics (TH) system codes, an assembly of models and
correlations that simulate physical phenomena and the behavior of system. Technical
challenges dealing with the subject are discussed in this paper with the prospective of TH
codes model uncertainty characterization. A literature review was conducted on the subject
matter to evaluate the state of the art on the topic. A key characteristic of thermal-hydraulics …