I hope I'm misremembering that but it's a pretty strong memory that totally locked in for me that that water is not necessarily dangerous.
I bet there's some good chance of getting wacky extremophiles though!
Hot spring baths usually top out around 42-43C
edit: sorry for being lazy, I scrolled a bit more and found it.
But now 100% sure that actually happened. Also it was likely a professor and not a working engineer drinking the water which makes much more sense.
While I do see this as a form of hazing which I am morally opposed to-
8oz (.237 liters) of primary coolant in a properly maintained pressurized water reactor might contain up to 13mrem of orally ingestible radiation, or approximately the radiation of a chest x-ray. (For comparison you get between 3-8 milirem on a 7 hour transatlantic flight)
Don’t make it your primary source of hydration and you’ll be ok. If the fuel is degraded or there is a leak (unlikely in properly maintained PWRs) the radiation dose is significantly higher.
I'd drink it. It's just extremely pure water, with a nuclear flashlight at the bottom of the pool - which no one could see, even if they had gamma-ray glasses on[1], because the water attenuates it so much.
[0] Or ions of hydrogen or helium, in the case of alpha and beta radiation.
[1] Which it turns out were way less cool than the Sea Monkeys(tm).
The primary coolant is not simply pure water; it contains boric acid, lithium hydroxide, dissolved hydrogen, and trace corrosion products like iron, nickel, cobalt, and chromium. Under power level neutron flux, some of these elements become short- or medium-lived radionuclides. Once removed from the core, most of the activity decays within minutes, but during operation the water is measurably radioactive.
An eight-ounce sample taken from the loop at power would carry roughly the dose of a chest X-ray before it decayed away, due to these activated isotopes rather than residual photons [EPRI PWR Primary Water Chemistry Guidelines; NUREG-1437][0].
I was on site for the mid cycle outage of three mile island unit 1 around 2005. I did the data sync and transfer for the steam generator inspection, but got tutored by some old PHDs during the down time.
[0] https://downloads.regulations.gov/NRC-2020-0101-0142/content...
