If you release a TNT mine cart from a dispenser on a booster track it will stay there..you can repeat this till (the amount of times i did it) around 30 times(check the entities) then activate the booster track,when hit by the activator rail a nuclear explosion similar to big explosions from mods as they explode in the exact same place the exact same time. Don't know how you can fix this, good luck! I forgot to activate the activator track and the tnt minecarts went on forever endlessly (you can see from the coordinates in the screenshots) i then punched the cluster of tnt minecarts and i was blasted into the air and when i went down it was a giant crater, this is cheap to make and could be an easy griefing tool or a vanilla nuclear bomb, as this can be expanded infinitely. (I saw the post about this earlier but that was more than a week ago and it said it was resolved but it wasn't so im reporting my version)