I'll just make the assumption that it explodes in a shitty milky glassy mess, with slightly rewarding visual affects, that would be greately outweighed by the saddening departure of the beloved family microwave. Oh woe.
So, unless you have a spare microwave, or someone you dont like has a microwave, then you probably shouldnt try this at home. I suggest doing it at someone elses house, that way you'll still have a place to live when the inevotable BOOM happens.
Much fun can be had with radiation, kids. Why not try putting some 9 volt batteries in there, maybe a hand grenade even. 🙂