Well it certainly seems to have put the situation under control...

if by that you mean it has partially (and to what extent is unknown) isolated the thing we can't control at all and will be cleaning up for 30+ years (stated by nuclear expert in video fta), then yeah it's all fine. unless you can prove that all ill effects are contained within that exclusion zone, it's not control, it's the illusion of control to make yourself feel better.

so if they're finding radiation in rice crops hundreds of km away, is that still control?

As I said, we may not be satisfied with the control, but isolation is in fact a type of control.