Have you done a game cache verify?
Does this happen on a previous save or new game?
Are you using mods?
I had this problem, it was actually my power supply... if it is your power supply it will get worse, and eventually start doing it in other games. With Explosions, like for me the Gatling Gun Explosive shot it would happen. But yeah I am betting it may be your psu... as the gpu is asking for more power to handle the explosive affects and lights the game will CTD, eventually it will start just Shutting down your PC randomly while playing. While this was going on I could play other games no issues, even make it though 3dmark Firestrike but was getting about a 1k score lower than most.