This seems like a perfect opportunity to use robots, since they aren't nearly as vulnerable to radiation as humans are.

For example, here's a description of why attempts to use water canons to cool fuel rods failed:

"Hopes were also raised when several police water cannons, designed for use in riots, were brought in and used to blast water towards the empty pool next to reactor number four in which spent fuel rods were in danger of melting.

Again, the high radiation readings meant the machines could not get close enough to the plant to get the water on target, and at one point the vehicles were forced to retreat, before resuming attempts that had limited success."

http://www.montrealgazette.com/news/Desperate+measures+kamikaze+mission+cool+exposed+fuel+rods/4458612/story.html

Why couldn't have a mobile robot on treads be fitted with a camera and water cannon and be remotely wheeled in to position to aim the cannon at the pool containing the spent fuel rods?

Or this:

"Jaczko, chairman of the Nuclear Regulatory Commission, said his staff in Tokyo had been told by Japanese utility officials that cooling water that normally covers spent fuel was nearly or totally gone from an uncovered concrete pool above reactor Unit 4. ...

'We can't get inside to check, but we've been carefully watching the building's environs, and there has not been any particular problem," Hajime Motojuku, a spokesman for Tokyo Electric, said'"

http://www.nytimes.com/cwire/2011/03/17/17climatewire-fukushima-crisis-worsens-as-us-warns-of-a-lar-9187.html

Why not use a little remotely operated helicopter or plane fitted with a camera, much like many hobbiests do around the world? It could be flown in to and through the building, or at least in a very close flyover of the building, and have a look inside.

Or, even simpler, why not just use a robot mounted on wheels or treads and carrying a camera? It could simply be remotely directed to drive in to the building and send back a video feed of what the cameras showed.

Japan is world-renown for its robotic technology. And yet in this disaster they are not using robots to go where humans can't because of the radiation risk. Why?