Endoscopes. A bundle of fiberoptic passively moves the image a few meters back to where a camera can run outside of the high radiation. Or even older-school, use mirrors/lenses/prisms as one would in a submarine's periscope to move the image far enough away.

Do you really think the engineers building a robot to go into Fukishima have never once looked at the first handful of google results for "radiation hardened camera"?

Eh, I did some work with a team building a robot for maintenance inspections on an accelerator. Their client had come to the conclusion that the cost-benefit on radiation hardened cameras was questionable, and advised them to select inexpensive off-the-shelf cameras that could be regularly replaced in a cost effective way.

Radiation hardening is tricky, there are tradeoffs involved and lots of reasons you might choose different points on the spectrum from "disposable robot" to "robot expected to have a long service life in a radiation environment."