I’m sorry to hear that Remmy. I will look into the best I can, however, as a reminder we do have WorldGuard enabled on the server. It’s not a perfect solution but it does secure most inventories/machines.
The turbines turning off, well I have had that issue myself, especially if there was a server crash. But even on some server restarts some of the turbines will just forget they were turned on. This could have also, with the turbine off, increased the heat of your reactor as there was no longer a steady flow of water back from the turbine. The increased heat would likely have increased the fuel consumption, but not sure if this is what happened for you.
I think this might have actually been the issue. I think around that time, I mistakenly had only a portion of the reactor chunk loaded. If the reactor acted wonky, and overheated burning hot, it might have burned though all the yellorium. Strangely, I did not have the equal amount of Cyanite. Since I have increased my chunk load, I haven’t had any missing yellorium. Who knows.