[13:37:30] [Server thread] [FML/WARN]:
HBM's Nuclear Tech - Extended Edition loaded a new chunk [23, -16] in dimension 0 (overworld) while populating chunk [24, -15], causing cascading worldgen lag.
This problem seems to happen a lot and I have no idea how to fix this

There is no fix; that's just hbm loading stuff, it doesn't really affect gameplay. If you want it to stop showing in console, you can go to the forge config file and disable cascading worldgen logging