Freeza, I think that the tubes would cut off the explosion. If you have the fuel tank further away from the space port, its destruction would have no hp impact on the SP. In fact, if I remember correctly, each tube section has emergeny "blast" doors that snap close the second any threat to the stability of the inside of the tube occures (such as the destruction of a building) which is why your AL only damages other structures when they are within a certain distance without wall protection. Even a 1-tile thick wall was enough to severely decrease the damage caused.
Unless you are going to completely change how tubes work in the storyline, I think that this is a good idea