The fuel crew at the airline I work for has to vent the tank(s) to below the explosive level (not ABOVE the explosive level, mind you) before work or entry. (I'm so glad I've "lost" my qualification for fuel tank entry - lol.)

On a slightly different plane, however, I believe the fuel tank explosions are ENTIRELY too huge. There is a nice story in Warpath Across the Pacific about a B-25 with an empty (with a few unusable gallons in it) 60 gallon lower fuselage fuel tank (in place of the useless lower turret) taking a direct AAA hit, catching fire, then exploding, blowing out the windows and the top turret's plexiglas leaving the turret gunner (nobody was seriously hurt) wondering "what the hell just happened?". In game, of course, there wouldn't be anything left...