Bananas emit detectable radiation, so you should probably choose different thresholds of what causes you to consider something dangerous.

They will still try to decontaminate you of any radioactive materials they can scrub off as a matter of course, but 300 counts per minute, while noticeably higher than background radiation levels, is pretty benign in the grand scheme of things. The fact that you can still count individual radioactive emissions is incredibly good news compared to how bad things could be.

Especially since the reactor will have been shutdown for some time by definition, if the reactor cavity is open enough to fall into. Hopefully the low rate of radioactivity evidenced by the counts on the person's hair is matched by the level of radioactivity in the water.

And on that note, medical attention would also be provided as a matter of course after a fall like this, but it seems to me that the physical injury of falling some distance and possibly hitting metal on the way down is going to be more of a danger than the radiation, especially compared to the sources of radiation people naturally run into (especially cigarette smoke, whether primary or secondhand).

I think you're softly implying things are more dangerous than they actually are, possibly due to not understanding just how insanely risk averse the nuclear industry is in the US. You could jog around a reactor chamber every morning and under a "normal person's" risk tolerance, you would never, ever be exposed to any danger. That worker who fell in the reactor pool seems like they got a radiation exposure equal to approximately a dozen chest x-rays (it's ambiguous though because they don't specify what tool was yeilding 300 counts per minute, nor do they give the total mSv).

The NRC would make you attend training and get decontaminated if you had to cross a street if they operated the roads.

It's not open to the public, but workers have to go into dangerous places to do maintenance. The refueling process, for example, requires removing spent fuel rods and inserting new ones, and for that the core has to be opened. It's not running, i.e. fissioning, but it's still radioactive material (water included).

It seems reasonable and prudent to go through decontamination after this sort of thing, but if the worker had just gone home to their family soaking wet without changing, there would still have been close enough to zero risk to anyone (again, cleaning up and making sure this is the case is a very reasonable thing to do).

This sort of place is safe enough to bring your kid into without significant precautions (I got to do this as a kid—it was really cool). The biggest risk by far is drowning.

Relevant XKCD: https://what-if.xkcd.com/29/

In addition to what most of the folks are saying:

0) If you've not read this chart, do carefully read it: <https://xkcd.com/radiation/>. If you've read it before, take some time to carefully re-read it.

1) The guy's getting sent off to seek non-emergency medical attention. I bet you an entire American Nickle that that attention is almost entirely for injuries sustained in the fall, rather than for radiation exposure.

I get a feeling that there are a lot of people trying to minimize this incident for some reason.

What you "need to" do is often not decided by a rational risk assessment.

"Complaining about residual radiation is for the weak." -- Lt. Worf probably

numbers matter. A human naturally gives off 0.2mSv/year. so basically you are emitting radiation right now, just very slowly. They had 300 counts per minute which would e around 6200 mSv year. But how much is that? the limit in a year for some body parts goes up to 500mSv year for workers. But that's if their body are getting that much radiation for the whole year.

TL;DR you're always getting some ionizing radiation, how much matters.