A worker fell into a nuclear reactor pool
121 comments
·October 26, 2025Animats
croemer
Archive of [2] (blocked me): https://archive.ph/0pzuY
arthurcolle
300 CPM in hair after decontamination is a massive red flag. If this is from systemic circulation, could be GBq-level total body activity.
The non-emergency classification is bureaucratic nonsense. This is an internal contamination event with unknown but potentially severe consequences.
ramchip
From: https://www.vice.com/en/article/a-nuclear-plant-worker-fell-...
> According to federal reports, the contractor ingested some of the reactor water before being yanked out, scrubbed down, and checked for radiation. They walked away with only minor injuries and about 300 counts per minute of radiation detected in their hair.
> That sounds like a lot, but apparently it isn't terribly serious. He underwent a decontamination scrubdown and was back on the job by Wednesday.
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arthurcolle
Litvinenko had about 10 MBq in his body and died in 3 weeks.
This might be 500+ MBq (0.5 GBq). Yeah it's a different isotope, but clearly not a "non-emergency"
malfist
Can you quantify why you're better qualified to assess risk from this brief report than the nuclear experts on site that know the full picture?
arthurcolle
I learned a few things from my father along the way. I can share my notes if you'd like
malfist
I'm sure your father is a very accomplished gentleman. But I was asking why your armchair analysis is better than the experts who actually know what happened here?
__MatrixMan__
Quantify? What kind of number would satisfy your request?
tt_dev
This is bad but cavity water radiation is usually very weak. Ingestion could be bad but its not like he swallowed a uranium isotope which would be catastrophic.
robocat
FYI:
the primary hazard from acute, high-dose uranium ingestion is chemical toxicity leading to acute kidney failure (nephrotoxicity), not radiation.anothernewdude
Fuck me, is there anything fun that isn't nephrotoxic?
arthurcolle
Menu tonight is neurotoxic or nephrotoxic
IlikeKitties
The Uranium Isotopes would also not be that terrible. It's the fission products that get you.
mlindner
I wouldn't even call it bad. Reactor pools have basically zero radiation at the surface. The water is constantly filtered and kept very pure to remove contaminants that can be activated by neutrons.
Even drinking it I would think would be completely fine. The water itself doesn't get activated.
happyopossum
Then where did their radioactive hair come from?
Brian_K_White
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 a prepper site that doesn't cite their own sources.
I found this: https://www.energy.gov/ehss/articles/doe-ionizing-radiation-...
Which uses rem instead of cpm. An on-line converter of unknown quality says 300 cpm is 500 rem, and the pdf from the .gov site says 500 rem is "death probable in 2-3 weeks", but I think that chart is saying that's whole body & no therapy. Where this is probably mostly hair that can be just cut off totally let alone washed, and so the elevated exposure is is probably both low and short duration, and medical therapy (whatever that means, if any in this case) on top.
I can't tell, could be the same as just visting a country with a slightly higher background that isn't a problem for anyone, to dead in a month. Leaning towards no problem just because of the short time and apparently mostly external and removable source.
roenxi
The pool. But it isn't necessarily a problem - your hair, right now, is radioactive. Presumably wouldn't trip a measuring device because it'd be background levels.
The linked report doesn't say how radioactive his hair is or give any indication of whether the person in question is threatened by this reading. Could be bad, could be nothing, we just know it is higher than normal.
jojobas
Water itself is activated by neutrons, even if slightly.
slicktux
I’ve heard of people falling into the spent fuel pool but never the reactor pool. Usually there are strict FME barriers in place and one cannot even look over into the pool without violating the FME. I wonder what led to the event? Definitely an OSHA recordable!
hshdhdhehd
> Non Emergency
I guess in a nuclear reactor there is a lingual shift and the word emergency cant be used for just any old 911 call.
Like how Australians apparently call a jellyfish bite "uncomfortable"
anakaine
Aussie surfer here, the stings typically are uncomfortable. Some of the deadlier ones can be close to painless and only result in itching and result in you dying from respiratory failure 24 hours later. Others are downright painful with even strong opiate based pain killers struggling to cut through the pain.
viraptor
Also it's in a way normalised to happen in a few places with beaches. There are vinegar stations every 100m or so. Basically a "yes, it will happen to a few of you".
https://www.reddit.com/media?url=https%3A%2F%2Fexternal-prev...
noduerme
Is the deadly itchy one of those tiny box jellyfish? More than sharks or crocs, this is why I was an absolute coward and decided not to get in the water in Queensland. There are lots of ways to die, but I'd prefer not to blame myself in my last moments.
cal_dent
Hahaha eeesh that 2nd sentence took a turn
thayne
It isn't an emergency. It was an accident that required medical attention.
If you fell in a lake and accidentally ingested some wayer known to contain some pathagen dangerous to humans, you might seek medical care, but I don't think most people would consider that an emergency. This is similar.
loeg
Nah this is literally just not an emergency. The water isn't very radioactive.
foobar1962
A bite requires teeth. Sharks bite. Snakes bite. Bees and wasps sting. Jellyfish and bluebottles sting.
Not sure about spiders. Are their fangs considered to be teeth? Platypus have venomous spurs, not sure what that’s called.
doubled112
Spiders bite. I've never heard it called anything else.
KPGv2
Spiders bite with their fangs, much like vampires bite with their fangs, they don't sting. I might call the tarantula "hair" that makes you itch a sting, but I would feel a bit silly calling it that.
dudidn
“worker fell off roof installing solar panels” — just getting ahead of the ‘anti-nuclear’ folks on here. Energy installations all come with risks, albeit nuclear long tail accidents are mutli-generational and externalised to people not involved in managing the risk
robviren
I greatly appreciate the nuclear industry. Nuclear field engineering was my first "real" job out of college and they really committ to safety. Transparency in this industry is inspiring because everyone involved knows that one screw up and that's the end of the US nuclear industry. Good luck getting oil and gas to be accountable and as transparent about incidents. I carry the culture into the rest of my work and appreciate being involved. Wish events like this didn't happen but it is not of significant danger and I find it great that they communicate even "smaller" issues.
sigmar
It doesn't say worker, just "person." I could understand falling in with some freak accident where you trip. But they ingested the water?!
andy99
Knowing nothing about nuclear reactor design, why would there ever be a dangerous pool that people could walk by that wasn’t covered? Hard to believe it’s like some kind of Bond villain complex with open pools everywhere. This must have been in the course of some kind of servicing that required opening something that normally stays closed?
donatj
Because it's generally speaking, not that dangerous. Water is very good at blocking radiation. That's part of the reason why the pool is filled with it to begin with.
andy99
I personally consider an area dangerous if I need to undergo radiation decontamination after entering it, continue emitting radiation after decontamination, and need to seek medical attention. Maybe the nuclear regulatory bodies have differen definitions?
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forthac
They typically have a railing around them. The circumstances of this incident are unknown beyond a small set of details. The report indicates that the person who fell was wearing a life vest, it is likely they were doing work around the pool beyond the normal safety barriers.
hammock
When I was a kid I was amazed at how many of the other kids would take pool water in their mouth and drool it out, simply as a normal part of their treading water. I thought they were weird for this but it was really about 1 out of every 3 or 4 kids I noticed that did this.
rtpg
probably likely just a thing that happens when you suddenly fall into a pool of water?
pixl97
I mean that's something that happens commonly when people fall into things like pools. When you jump into a pool you tend to take a breath before you do so, so you don't suck in water. When you fall into water it's much more common for people to aspirate or swallow water from the surprise.
viraptor
Depending on a velocity, it also doesn't matter if you took a breath or not. Fall in quickly enough and at just the right angle (you can even do that from a fast water slide) and the water will be forced through your nose into lungs/stomach. (Unless you hold it closed)
_qua
Not a good place to be a klutz!
almosthere
Is he going to die no matter what or is this survivable?
jasongill
Ultimately, yes; he will die no matter what.
almosthere
As you get older this pedantry gets really tiring.
brongondwana
The good news is, you have less time to be annoyed by it
thayne
I'm not an expert but it definitely doesn't sound like an immediate threat to his life.
Hobadee
I have SOOO many questions, and this report answers SOOO few of them.
JasonSage
My question is what happened between when they went in the water and when they got off-site medical treatment. 7 hours seems like a long time. Is there on-site medical that would be doing something during that time?
_qua
Realistically, there is little to do besides decontamination which I'm sure they're equipped to do on site.
analog31
Anecdote: My house mate in grad school was working in a national lab when an experiment caught fire and the fire consumed a certain amount of radioactive material. (Tiny little buttons used for calibrating detectors). He was on shift and was the person who discovered the fire and pulled the alarm.
Among other things, he had to sit inside an enclosure made of scintillator material for a period of time, to make sure he wasn't contaminated. Then he also got blood tests for heavy metals etc. They pretty much went by the book for all of these tests.
Also, the facility is the only place that's equipped for this kind of situation.
slicktux
It’s a process to come into a high radiation area, as well as, a process to come out; I’m sure the worker was not injured so they processed he/she out and decontaminated the individual and did a whole body count. Then release him to medical for evaluation…which in itself is a process.
hshdhdhehd
Like what is a reactor cavity? HN title makes it sound like they fell into the reactor but maybe this is some sort of moat or something? what did they fall into and why?
PaulHoule
Almost certainly a refueling outage, this video will give you a good image of it
Centigonal
ooh, thank you for this!
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_qua
Interesting page overall. Didn't realize reactors get scrammed that often.
Palisades MI reactor. Currently shut down and de-fueled but a restart of this reactor is apparently underway, with new fuel assemblies being delivered.[1]
Worker was wearing a life vest.[2]
[1] https://en.wikipedia.org/wiki/Palisades_Nuclear_Generating_S...
[2] https://www.mlive.com/news/2025/10/michigan-nuclear-plant-wo...