Why can't you "See" inside a nuclear reactor?

Yet another question about nuclear reactors in the wake of the quake…

From the CNN Website:

Well, of course there’s no way to directly see inside a reactor, and I understand they have to judge whether or not there’s a meltdown by gauging things like the pressure build-up, but why are there not more sophisticated methods of determining what’s going on in there? It just seems so low tech and uncertain for something that is potentially a wee bit hazardous.

Here’s the link: http://www.cnn.com/2011/WORLD/asiapcf/03/12/japan.quake/index.html?iref=NS1

I’s hard to make sensing equipment (lenses, cameras, illumination, etc) that can withstand the extreme heat, pressure, and radiation inside a reactor. Even if you put in a quartz porthole, it would eventually get fogged by radiation damage.

To bright to see whats going on anyway?

It’s not too “bright” in the visible light spectrum during normal operation to see what’s going on. Except, as beowulff mentions, no remote viewing equipment can survive very long in the core environment. Here are some pictures of what light (Cherenkov radiation) that is visible looks like.