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A worker fell into a nuclear reactor pool

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Re: A worker fell into a nuclear reactor pool

#501

Post by Movah »

I wonder if it had anything to do with the empty "alcoholic bottles" being found?

FITNESS FOR DUTY (FFD) EVENT

The following information was provided by the licensee via phone and email:

"On 10/25/25, at approximately 1230 EDT, 3 empty alcohol bottles were found in the protected area by a contract employee. Site security was notified and took possession of the empty bottles which were removed from the protected area. The individual who accidentally brought in the empty alcohol bottles with other non-alcoholic empty bottles was tested for FFD and was negative. This event is reportable in accordance with 10 CFR 26.719(b).

"The NRC Resident Inspector has been notified."

Re: A worker fell into a nuclear reactor pool

#502

Post by dundercoder »

djtriptych wrote: post #356
afiori wrote: post #246

Earlier quoted context omitted.

My understanding is that reactor and waste pools are some of the least radioactive environments as they are constantly monitored for leakage.

I'm pretty sure the engineer at the nuclear plant I visited in elementary school drank a glass of water out of that pool to demonstrate how safe it was. 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.

Had a buddy on a nuclear sub drink water from the primary coolant loop when he joined the team.

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.

Re: A worker fell into a nuclear reactor pool

#503

Post by dundercoder »

ErroneousBosh wrote: post #375
djtriptych wrote: post #356

Earlier quoted context omitted.

I'm pretty sure the engineer at the nuclear plant I visited in elementary school drank a glass of water out of that pool to demonstrate how safe it was. 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.

Serious question, as daft as it might sound - do they have to chlorinate the water to stop stuff growing in it? I'd expect it'd be about "swimming pool" warm so just great for all sorts of manky algae growing.

Chlorinating the water would have adverse effects on material strength and longevity. Even irradiated and heated to 50c, I’ll bet there’s some extremophile bacteria in there somewhere.

Re: A worker fell into a nuclear reactor pool

#504

Post by haskellshill »

quantumcotton wrote: post #431
haskellshill wrote: post #427

Earlier quoted context omitted.

> People can drown on dry land from about a tablespoon of water getting into their lungs. Well, I don't think there's such a big risk of that. Falling into a pool is something most of us have probably done. Being pushed by a friend as a kid for example. The risk of drowning is probably pretty comparable to the risk from the radiation (negligible).

I didn't expect this level of ignorance here. Maybe reddit but this is crazy.

I didn't expect this level of unfounded ignorant hysteria here. Have you really never gone swimming and inhaled some water? Did you go to the hospital?

> In the past, these terms were used to try to explain that some fatal drowning victims had very little water in their lungs at autopsy. Now it is understood that little water enters the lungs during drowning. Moreover, when water enters the lungs, it is rapidly absorbed when breathing starts again. The amount of water that enters the lung does not determine the amount of injury or determine the treatment of drowning. The amount of injury from drowning is due to how long the victim is without oxygen.

Source: Red Cross

Re: A worker fell into a nuclear reactor pool

#505

Post by qjh »

Brian_K_White wrote: post #121
happyopossum wrote: post #80

Earlier quoted context omitted.

Then where did their radioactive hair come from?

That's what I was thinking, but it does look like 300 cpm for a few hours is essentially nothing, or it looks real bad, I can't tell. I found this: Days to receive chronic dose for increase cancer risk of 1 in a 1,000 432 (at 100 CPM) 86 (at 500 CPM) Ok so 300 for an hour (we'll assume the hair is cut off and the exposure either stops or 90% reduces) means no problem. Don't do that every day that's all. But it's from…

Obligatory not a nuclear safety or health physics person, but I am a particle physicist and I deal with radiation. CPM is a rather annoying unit because it doesn't convert to dose very well. If you have external 300 cpm (eg. hair), but all of that is in the form of alpha radiation, your actual dose is essentially zero.

It's worth noting that humans are typically radioactive to the level of 3 kBq, or 3000 disintegrations per second, so if I ever realised I had 300 cpm of radiation on my skin as measured by a device that is sensitive to alpha, beta, and gamma, I probably would just shrug and wash it off. Where it might be a problem is if I am dealing with only alpha and beta isotopes, and I'm getting 300 cpm on a gamma-sensitive detector, meaning that the _secondary radiation alone_ is 300 cpm.

(Realistically, I and the radiation safety officer overseeing whatever I was doing would be in serious trouble and have a ton of paperwork, but I just mean it in the abstract)

I mean, 10 grams of potassium has ~300 Bq (that is 300 disintegrations per second) of radiation, so I think I should be able to get my hair far more radioactive than 300 cpm on a beta-sensitive geiger counter if I just slather myself in low-sodium salt from the grocery salt. The salt might be bad for my scalp, I don't know, but the radiation is fine. My point here, though, is that I don't know what equipment the 300 cpm is measured with, what the thresholds are and what the window material is, and that can change things greatly, but my non-professional opinion as the wrong kind of doctor is that it's...probably not a big deal.

We've actually used KCl as a low-level radiation source before, and we joked that when the experiment is done we can just take it home and use it to season dinner.

Re: A worker fell into a nuclear reactor pool

#506

Post by jjk166 »

wiz21c wrote: post #490
johnisgood wrote: post #408

Earlier quoted context omitted.

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

On the picture, the fuel rods are indeed protected by a huge quantity of water above them. But what happens below them ? They seem to be in direct contact with the ground...

People tend to avoid casually tunneling under nuclear pools.

Re: A worker fell into a nuclear reactor pool

#507

Post by jjk166 »

ErroneousBosh wrote: post #489
monkpit wrote: post #483

Earlier quoted context omitted.

Your lungs can handle a tiny amount of water just fine. It’s not pleasant but it’s fine. You’re probably thinking of something along the lines of pneumonia, which is different than breathing some water and coughing it back up. For the record, I think the GP comment is way off-base saying drowning is uncommon.

No, I'm not talking about pneumonia. If there's a bit of water in your lungs, a surprisingly small amount, it causes massive inflammation and your lungs start to fill with fluid. It's called "secondary drowning", and it happens a couple of hours after. My water rescue course is up to date. When's yours due for renewal?

https://www.redcross.org/take-a-class/resources/articles/dry...

Re: A worker fell into a nuclear reactor pool

#508

Post by haskellshill »

ErroneousBosh wrote: post #489
monkpit wrote: post #483

Earlier quoted context omitted.

Your lungs can handle a tiny amount of water just fine. It’s not pleasant but it’s fine. You’re probably thinking of something along the lines of pneumonia, which is different than breathing some water and coughing it back up. For the record, I think the GP comment is way off-base saying drowning is uncommon.

No, I'm not talking about pneumonia. If there's a bit of water in your lungs, a surprisingly small amount, it causes massive inflammation and your lungs start to fill with fluid. It's called "secondary drowning", and it happens a couple of hours after. My water rescue course is up to date. When's yours due for renewal?

As the saying goes, "a little bit of knowledge is a dangerous thing". Your "water rescue course" taught you something that's clearly wrong, as we see with the sibling comment, while my common sense and just everyday life experience led me to the correct conclusion.

Re: A worker fell into a nuclear reactor pool

#509

Post by IAmBroom »

dundercoder wrote: post #502
djtriptych wrote: post #356

Earlier quoted context omitted.

I'm pretty sure the engineer at the nuclear plant I visited in elementary school drank a glass of water out of that pool to demonstrate how safe it was. 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.

Had a buddy on a nuclear sub drink water from the primary coolant loop when he joined the team. 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 t…

That makes zero sense. Radiation is not a component of water; it is literally photons[0]. In the nanosecond after you fill the glass, all the radiation in it has left the volume.

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).

Re: A worker fell into a nuclear reactor pool

#510

Post by dundercoder »

IAmBroom wrote: post #509
dundercoder wrote: post #502

Earlier quoted context omitted.

Had a buddy on a nuclear sub drink water from the primary coolant loop when he joined the team. 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 t…

That makes zero sense. Radiation is not a component of water; it is literally photons[0]. In the nanosecond after you fill the glass, all the radiation in it has left the volume. 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,…

Radiation isn’t contained in the water as photons, but the coolant itself becomes radioactive through neutron activation. Even with intact fuel rods, oxygen in the water turns into N-16 with a half-life of about seven seconds, and trace metals like nickel and cobalt form isotopes such as Co-58 and Co-60. These emit strong gamma radiation while the reactor operates.

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...

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