That's a stretch. The Exclusion Zone[1] is about 2600km^2 (1000 sq mi) but it's only declared uninhabitable, there are people living there (though not saying it's a wise move to settle down there).
There are some areas outside that which is also deemed dangerous, but that's the order of magnitude we're talking about.
For reference, Europe covers an area of about 10 million km^2 (almost 4 million sq mi).
Also note that we don't have a good handle on how lower levels of radiation affects us, and there's discussion around if the prevailing method[2] to estimate exposure effects over-estimates the effects at lower exposures.
Sorry, brain seemed to filter away the crucial "almost".
However it goes back to how "intermediate" levels of radiation affects us. Even if the water had caused the remaining cores to blow up as well[1] then it's still not clear just what the impact would be[2].
I might not be remembering correctly, but I thought they had to tunnel under it to stop the core from burning down into the water table which would spread the nuclear disaster far and wide. Not to stop the steam explosion.
There are some areas outside that which is also deemed dangerous, but that's the order of magnitude we're talking about.
For reference, Europe covers an area of about 10 million km^2 (almost 4 million sq mi).
Also note that we don't have a good handle on how lower levels of radiation affects us, and there's discussion around if the prevailing method[2] to estimate exposure effects over-estimates the effects at lower exposures.
[1]: https://en.wikipedia.org/wiki/Chernobyl_Exclusion_Zone
[2]: https://en.wikipedia.org/wiki/Linear_no-threshold_model#Cont...