Conjugate heat transfer and boundary condition phenomena in rod bundle experiments with liquid metals

Research outputpeer-review


The maximum fuel cladding temperature is a key factor for the safety assessment of heavy-liquid-metal cooled reactors. In this context, experiments at prototypical operating conditions in terms of temperature, flow velocities and power density using electrically-heated fuel pin simulators have been completed recently and further ones are currently under construction at several laboratories worldwide. In parallel, computational fluid dynamics (CFD) is used for simulating the temperature distribution in the experiments and extrapolating the results to postulated accident scenario in the reactor. For a better agreement between the CFD results and the experimental data, conjugate heat transfer phenomena must be taken into account, including some specific features of the experiments which might be different than in the reactor core geometry. In this work, experiments performed at KIT (Germany) using 19-rod wire-wrapped bundle (with and without blockages) cooled by lead-bismuth eutectic are simulated using CFD with different models representing the conjugate heat transfer and boundary conditions. In a first model, a uniform heat flux boundary condition is applied at the solid-liquid interface. A second model incorporates the heat conduction in the rod cladding and wire spacers. In the third model, a volumetric heat source inside the pins is imposed and a detailed representation of the internal solid components is taken into account. This last effect is shown to have a significant influence on the predicted temperature profiles, particularly for asymmetric scenarios, like the presence of a local blockage.
Original languageEnglish
Title of host publicationThe 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics
Subtitle of host publicationNURETH19
Place of PublicationMol, Belgium
PublisherSCK CEN
Number of pages16
ISBN (Electronic)9789076971261
StatePublished - 6 Mar 2022
Event2022 - NURETH - 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics - Brussels
Duration: 6 Mar 202211 Mar 2022
Conference number: NURETH19


Conference2022 - NURETH - 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics
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