The reason I'm not worried is because we have (albeit tired, understaffed and under resourced) experienced engineers on the ground.
It's not as if it's just random people watching rods of metal in water tanks going 'oooo pretty'.
Even if the worst happened, and all the pumps failed and electricity goes out I'm sure the engineers would come up with a good solution. (Please remember in the event of complete coolant system failure it would take a few weeks for the water to evapourate).
Hypothetical worst case scenario (VERY VERY UNLIKELY)
Ok, let's say ALL the engineers got their degree from youtube tutorials and an online correspondence course, on par with Homer Simpson, and that they have ZERO resources (They actually have a lot of gear on hand, but let's forget about that for a moment). Lets then say that Vlad the tank operator decides to shoot all the pumps with his T-72 because he's bored. In this very unlikely scenario, you would see clouds of radioactive steam evapourate. Please note, this steam would not be very radioactive, and unlikely to kill someone not at the power plant. You would also be bombarded with nuclear radiation if you stood near the now empty pool (remember water basically acts as a big sponge when it comes to nuclear radiation, so if you remove the water someone standing near the pool will be exposed to a lot of radiation).
TL;DR:
Even in the worst case scenario it would only affect people working at the plant, and if shit hit the fan the personnel there would have many weeks of notice to skedaddle.
Edit: This only applies to Chernobyl, please don't take this out of context and apply it to other Ukrainian nuclear power plants, if an active reactor got blown up by a bunker buster, it would be a million times worse than described above.
