20%+ is highly enriched uranium, which is the maximum enrichment for compact nuclear reactors (like the one shown in the picture).
90%+ is weapon's grade uranium, too much for any reactor unless you want an uncontrolled nuclear chain reaction.
Stupid site is stupid.
Edit: Wait... it's just plated with Uranium around a Californium core and they're talking about "weapon's grade" uranium? Gahhh! This is why I hate "news" sites. (They use Californium to produce extra neutrons so they can get away with a lower grade of uranium)
I think they worded it weirdly to get people to read. They never said the reactor had weapon-grade material, they just said that, that much material (3.5 pounds) wouldn't be enough to make a bomb.
And technically enriched uranium IS used in nuclear weapons, just not the stuff in the reactor.
Still this type of news reporting is a failure.
edit: This line is questionable
But why did Kodak have a hidden nuclear reactor loaded with weapons-grade uranium?
But it really doesn't give any direct information that the reactor had weapon-grade uranium. Heck, it wasn't really "hidden" (maybe to general public)and they told you the reason for the reactor later in the article. Even Fox-news didn't directly link the reactor with weapons-grade material.