I don’t like that. It took something like a RL week to deplete Co-60 in moderated reactor (so it’s much faster than normal). To get good nuclear fuel, It’s much faster to get U-235 from refining uraninite. And uraninite is available from worldgen.
So I see 2 problems: too much uranium from worldgen (and too little thorium in comparison), maybe too big fuel rod duration.
I don’t have suggestions what to do with worldgen. The same ores can be useful for other mods, so it’s probably not a good idea to reduce their count in vanilla GT6.
Fuel rod duration… it would be nice to have a configurable number, which means “how long is U-235 fuel rod duration in minutes?” (Currently 10 000 minutes). I mean, it would be one multiplier for all fuel rods’ durations.