I would think that radiation level would definitely depend on the size of the fuel "chunk" as you put it. Inside the core itself, sure, I could believe that level of radiation intensity, but, also remember, the 3 most important factors in reducing radiation dose.. Time, Distance, Shielding..focus on distance for this case.. no matter if they were looking into the core, standing above it, etc, there was still quite a distance between the emission and thier location. So, while inside the core may have been 20k/hr, I doubt the persons "observing" the core would have experienced that dose rate, it would have been, while still QUITE lethal, quite a bit less than that... Whereas int he scenerio Kappa and you were speaking about (the irradiated fuel rod in open air over a fuel pool) the dose rate would be significantly higher, since the distance between the source, and the person observing, would be measured in feet, rather than tens or hundreds of feet...
Again, I don't work in this industry, nor do I have any training in it, although if I were starting out fresh and new, I would seriously consider it, I am just a person who is fascinated by all things science, and especially nuclear power/physics... so take my post here for what it's worth...