The force field/radiation scanner thing never really bothered me. It's clear what the dramatic purpose was for; the in-universe explanation doesn't trouble me. It's esoteric high tech something-or-other that Naboo engineers obviously realized they needed in that corridor. It fits with the mise en scene established in other sections of the generator complex so I buy it. Don't take this as sarcasm or a flame, but if the lack of explanation is upsetting, I've got no argument for you. The fact that we're never told why ESB's carbon freezing chamber is raised so high up off the ground (aside from the production designer's requirements) or why the edges don't have guard rails (aside from dramatic license required by the script) never bothered me.
It's like the power coupling for podracer engines or visible beams of light coming from blasters. They work the way Lucas says they work because he says they work that way.
This is why I'm in the EU=Canon crowd. The other writers think through the things GL tends to ignore.
EU=crapola. Droid Jedi, non-stop and unnecessary movie references and other junk. The only EU I've ever read that *felt* like Star Wars was Shadows of the Empire (which deserves a CG-animated movie) as well as the Han Solo and Thrawn trilogies (and even those were hit and miss). There's some okay stuff out there but most of it is dreck.