You're just confusing him now...
1.When the emblem of a sheild is plutonium its special effect is stronger
2.The body of a plutonium shield currently does not have a special effect, bs hasn't added it to the game yet (Or does it? skip to 5.), but when it does have a special effect you'll be the first to know.
3.All shields block things, the plutonium sheild does the same.
4.Theoretically uranium should be the powerhouse since it's one of the heaviest metals known to man, but I suppose that would require a small nuclear reaction...(Oh and fyi all elements higher then the atomic number 100 are unstable)
5.Finally, the special effect for the plutonium shield is...Confusion & Awe, It works on people!!! (Its more or less a side effect, the special effect for monsters is being worked on)
6.If you're still confused then I'll probably teach my dog how to control a nuclear reaction sooner then you'll understand.