1.9 MWt still seems like a huge amount of energy/heat for something that fits on a truck and is supposedly air-cooled (they claim no water is required).

Where does all that heat go?! They must have some very impressive fans.

Heat transfer has the lovely property of scaling nonlinearly by temperature difference. You need a lot of big fans to cool your CPU from 75C on the die to a 25C room, instead of a 50C difference these reactors will dump heat at hundreds of degrees C warmer than the local environment.

Yes, that's crazy. They say up to 1 MW electric which would mean (33% efficiency) 2 MW of heat to get rid of with air cooling. Later they mention facility heating which sounds more realistic, I guess?