The melting point of uranium metal may be around there, but these reactors would use a much higher temperature fuel form, such as the everyday uranium oxide (UO

The melting point of uranium metal may be around there, but these reactors would use a much higher temperature fuel form, such as the everyday uranium oxide (UO₂) used in nearly all commercial reactors, which melts around 2900°C. Usually it's the coolant and structural materials that limit temperature in nuclear reactors. These could use exotic materials like SiC for structure. Interesting that they use liquid metal heat pipes in this study to transfer the heat to the rock melting surfaces.