And microwave ? Particle beam ? Mason cannon ? Gravity blast ?

What are you trying to do with your cels ?!? :)

Eh, during the whole production process, people will
put their fingers on cels (sometime coffee, tuna
sandwitch or whatever else), keep them totaly un-protected
in normal room, put them under bright light, scan them
and so on...

It's not a camera film : puting them under light,
even direct sunlight or UV lamp for a little time
won't hurt them. It's only letting them under UV
for a long time that will end-up fading the lines.
(at least several continus days. Sure, it will fade
away faster if you happen to live under the ozon layer
hole)

Cheers,
Yann Stettler