Thermal equivalence between nuclear fuel rod model and experimental heater simulator

摘要

Method of formulating nuclear fuel rod model (typical materials for pellet and clad, including usual gas-gap), which is thermally equivalent to multi-layer experimental heater simulator (any materials in contact, and/or without/with gas-gap) is presented. Thermally equivalent typical fuel rod model is defined. To validate it, the HECHAN model able to use different layouts of multi-layer rod/simulator geometry with constant and/or temperature dependent thermal-physical properties is used. Comparison with measured data for cladding surface temperatures in both pre- and post-CHF regimes proved applicability of this approach in transients. The rod model is easy to define, without changing the source of standard thermal-hydraulic code—only through input deck. It is qualified for further use in COBRA 3-CP and COBRA-TF codes for their validation on experiments using the particular heater simulator design.