Core melting and molten migration behavior are hot and difficult issues in the field of nuclear reactor severe accident research. The Moving Particle Semi-implicit (MPS) meshless method has　potential　to　simulate　free-surface　and　multiphase　flows. In this study, the MPS method was utilized to simulate the melting process of UO~2~-Zr rod-type and dispersion plate-type fuel elements. The models of heat conduction with phase change, simplified UO~2~-Zr eutectic reaction, viscous flow and surface tension were implemented with the framework of standard MPS method. Then, the improved MPS code was used to simulate and analyze the process of high-temperature melting and characteristics of molten migration and solidification in the coolant channel, aiming at revealing the severe accidents for light water reactors (LWR), particularly the early core damage. The results showed that the degradation process of the dispersion plate-type fuel element may be faster than that of the conventional rod-type fuel element, and the melt was more likely to cause blockage of the coolant flow path. In addition, this study also demonstrated the potential of the MPS method for the study of complicated severe accident phenomena in not only traditional LWR but also advanced nuclear reactors in the future.


Numerical Study of Fuel Melting and Molten Migration Based on the Mps Method

Division / Sponsors: 
Power Division & Nuclear Engineering Division (NED)

Power Conference
Paper Proceedings: https://asmedigitalcollection.asme.org/POWER/POWER2020/volume/83747

International Conference on Nuclear Engineering
Paper Proceedings: https://asmedigitalcollection.asme.org/ICONE/ICONE2020/volume/83761

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