Archive of [2] (blocked me): https://archive.ph/0pzuY

dunno if the life vest bit comment of yours was sarcastic, but it is a funny remark for sure :-)

it sounds like "guy felt down in a volcano, but fortunately, he had a life vest"

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FYI:

  the primary hazard from acute, high-dose uranium ingestion is chemical toxicity leading to acute kidney failure (nephrotoxicity), not radiation.

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.

Sounds like it was a lot more serious for the water than for the worker

The Uranium Isotopes would also not be that terrible. It's the fission products that get you.

I loce their videos, too, but as far as I know the current US administration will shut them down at the end of this year. [0] [1]

But just now I read that a (sharply reduced) budget had passed the house? [2] does anyone know what the current state is?

[0]: https://www.csb.gov/assets/1/6/csb_cj_2026.pdf

[1]: https://www.pbs.org/newshour/show/only-federal-agency-that-i...

[2]: https://www.safetyandhealthmagazine.com/articles/27090-house...

That happens all the time; it's only news when something unusual happens.

This is not true at all. I have personally looked into a reactor pool. I remember thinking how easy it would be to literally just jump in. I mean, I'd trip about a thousand alarms and probably end up in prison, but....

was this place one of those who suffered firings as a result of the government shutdown? I believe at least 1,000 employs at nuclear facilities have been fired.

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.

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?

> The non-emergency classification is bureaucratic nonsense

FTA: “This is an eight-hour notification, non-emergency, for the transportation of a contaminated person offsite“

I read that as that the “non-emergency” classification isn’t for the victim or the “fell into a nuclear reactor pool”, but for the effects on those outside the facility of sending the victim off site.

A CPM value means nothing without additional context. Counts vary based on detector type and size, radiation type, energy, distance and geometry, all sorts of things. They're not comparable except in identical contexts.

This is why the Sievert exists as a unit.

As a general rule, falling into a reactor pool is probably fine, as long as you don't reach the bottom. (But please don't try it.)

There's even an XKCD "What if" about it. https://what-if.xkcd.com/29/

CPM is a measure of rate, GBq is a total amount. And 300 CPM is basically nothing. People live their entire lives in places where the natural background radiation is higher than that with no increased chance of cancer.

300 CPM on its own is both meaningless and not high.

CPM is a raw stat from the sensor. There’s many different designs of dosimeters and they all read differently so you have to ask “what brand and model did you use?” You then apply a function to the data to normalize it into a real unit.

But CPM is the cool thing that makes the click-click-click sound. (The absolute rate of clicks also is not useful.)

There is no circulation in hair, hair is dead, and it is produced slowly. Nothing about your commentary passes basic scrutiny.

Unless I'm misinterpreting what you mean, I believe if it was reflected in the hair in the immediate aftermath, it wouldn't reflect internal circulation because hair does not grow that fast. It would have been from exposure to the pool rather than any amount ingested.

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"

EDIT: (after 1 hr) - Litvinenko dose was 4GBq - I was wrong by 3 orders of magnitude. My bad

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.

There's no significant immediate threat to life or well-being. It's simply not an emergency. We're all constantly exposed to some ionizing radiation. It's a question of how much.

In this case, not much. It's still an exposure event and absolutely worth giving medical attention to assess continued exposure levels from ingested contamination and generally be overly cautious. But that doesn't mean it's ultimately going to be a significant factor in this workers risk for radiation induced disease. It's certainly better than living in the vicinity of coal mining and processing plants.

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.

Nah this is literally just not an emergency. The water isn't very radioactive.

Or how Brits call a civil war "trouble"

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.

i mean it might be a medical emergency but not a reactor emergency?

I thought this as well but given some other comments the measures numbers are open to interpretation/ spread. Also it could be considered a violation of the person's body if done without his consent.

Dude might prefer to keep his hair? Given the low exposure amount.

A spider will bite this guy and get the powers of a human.

Where is Jimmy Carter when we need him? And Rodney Dangerfield to explain how big Jimmy Carter is.

https://www.reddit.com/r/LiveFromNewYork/comments/1bh2edu/th...

If one falls into a tank like this, what steps are required to guarantee likelihood of developing powers?

same thought here

I've lived through three major nuclear incidents, and what they had in common, regardless of the political systems of the US, The Soviet Union or Japan, was not the transparency, it was the lying. It started immediately after each incident.

I'm essentially pro-nuclear, I just don't trust people who run it.

Can you recommend a book or two in order to learn about that culture? IMO we could use more of it in AI.

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This harmless incident shows us nothing aside from why nuclear is so expensive.

There is essentially zero risk to the operation of the plant (or this worker!) from such an event.

Imagine if oil and gas facilities were required for any worker fall to have federal government workers visit onsite, draft a report for review, have it examined by expensive niche lawyers with rounds of revisions, and then have it published it publicly.

This is just a silly example of the hysterical safety-ism involving anything nuclear-related in the US.

Yes, working in any job related to energy carries risks. Just ask a roughneck, lineman, or wind turbine installer.

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?

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?

Literally no amount of incident reporting is excessive when it comes to nuclear power. Not just because of the safety of the plant itself, but because so much is reliant on it.

It's important to identify even small defects or incidents so that patterns can be noticed before they turn into larger issues. You see the same breaker tripping at 3x the rate of other ones, and even though maybe nothing was damaged you now know there's something to investigate.

Having the infrastructure for reporting incidents is the expensive part.

Doing it often doesn’t really add to the cost. More reporting is helpful because it explicitly makes it clear even operational issues can have lessons to be learned from. It also keeps the reporting system running and operationally well maintained.

WebPKI does this as well.

That blog post is about the spent fuel pool. The link is about the reactor cavity.

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?

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.

probably likely just a thing that happens when you suddenly fall into a pool of water?

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.

Not a good place to be a klutz!

More radiation released also which is hard to get your head around.

Ultimately, yes; he will die no matter what.

He will be fine. He might not still have his job in a few months but other that, he will be fine. 300 CPM isn't even close to dangerous. You get a higher dose every time you fly in an airplane, or go to La Paz, Bolivia.

I'm not an expert but it definitely doesn't sound like an immediate threat to his life.

This is enlightening chart. Only Solar beats nuclear in deaths/Wh of energy. Even wind power results in more deaths. Additionally this uses very pessimistic numbers for large nuclear incidents and doesn't count thinks like deaths and health complications due to pollution and emitted radiation from fossil-fuel power sources (which emit way more radiation than nuclear power).

https://ourworldindata.org/grapher/death-rates-from-energy-p...

Really puts it into perspective

I'm not an expert in this topic but I've been working on a book in a related area and had to learn a lot. Here's what I can figure.

Unfortunately radiation medicine is pretty complicated and the report gives us very little info, presumably mostly because they don't have very much info. It will take some time and effort to establish more.

What we do know is that they measured 300 CPM at the person's hair, which was probably where they expected the highest count due to absorbed water (likely clothing was already stripped at this point). CPM is a tricky unit because it is something like the "raw" value from the instrument, the literal number of counts from the tube, and determining more absolute metrics like activity and dose requires knowing the calibration of the meter. The annoying thing here is that radiation protection professionals will still sometimes just write CPM because for a lot of applications there's only one or a handful of instruments approved and they tend to figure the reader knows which instrument they have. Frustrating. Still, for the common LND7311 tube and Cs137, 300CPM is a little below 1 uSv/hr. That wouldn't equate to any meaningful risk (a common rule of thumb is that a couple mSv is typical annual background exposure). However, for a less sensitive detector, the dose could be much higher (LND7311 is often used in pancake probes for frisking because it is very sensitive and just background is often hundreds of CPM). Someone who knows NRC practices better might know what detector would be used here.

That said the field dose here is really not the concern, committed dose from ingesting the water is. Ingesting radioactive material is extremely dangerous because, depending on the specific isotopes involved, it can persist in the body for a very long time and accumulate in specific organs. Unfortunately it is also difficult to assess. This person will likely go to a hospital with a specialty center equipped with a full body counter, and counts will also be taken on blood samples. These are ways of estimating the amount of radioactive isotopes in the body. In some cases tissue samples of specific organs may be taken.

I believe that the cavity pool water would be "clean" other than induced radioactivity (activation products from being bombarded by radiation). Because water shields so well the pool should not be that "hot" from this process. Most of those products have short half-lives which, on the one hand, means that they deliver a higher dose over a shorter period of time---but also means they will not longer forever and are less likely to be a chronic problem if they are not an acute one.

I suspect this will get some press coverage and we will perhaps learn more about the patient's state.

Another way we can get at this question is by the bureaucracy of the notification. An 8-hour notification as done here is required in relatively minor cases. Usually for a "big deal emergency" a one-hour notification is required. The definition of such an emergency depends on the site emergency plan but I think acute radiation exposure to a worker would generally qualify.

Radiation units are fiendishly tricky to convert between. Here, the only indication is that after decontamination their hair was still reading 300 counts per minute. CPM are instrument-specific and doesn't mean that's the correct number of disintegrations per second, nor easily converted to absorbed dose units, and this is after decontamination, and disregarding the amount of water they ingested.

All that disclaimer aside: a banana produces about 15 Bq (which is s^-1), i.e. 900 cpm.

"count" is that classical Geiger click, so 300 per minute is constant 5/sec gggggggg going on, which sounds bad but we don't know. They're boolean and also equipment dependent.

As others had said, more alarming part is that they ingested the water, which could go like defected Russian spy Alexander Litvinenko. But it could also be like man eating few bananas seasoned with expired Himalayan salt. The report just doesn't say how much of what was ingested.

Not at all. My scintillating counter will do 300 cpm as background. The most concerning thing here will be the ingestion of the water. Even low level emitters can be very bad when the are inside the body

If it was just swimming in it that would be one thing. Ingesting the water could be very bad, depending on what's in it.

Water is a pretty good radiation shield so probably not too much. Certainly not good for your health but probably not seriously threatening.

I guess that U.S. Nuclear Regulatory Commission is required to report any unusual events in the plants in the US, which would be reasonable. A worker falling into a nuclear reactor pool is unusual. The report itself doesn't seem like it's anti-nuclear in any way, and it clearly states "no impact on the health and safety of the public or plant personnel".

If you're asking why it's interesting for HN, I think it's actually because people are fascinated with nuclear, in a positive way.

Because another mutant might be joining our ranks soon.

I can guarantee you there will be a proper investigation and steps taken to avoid this in the future. The non-emergency classification here applies solely to the notification that the contamination was transported off-site. Not to the fact that the incident occurred. Every accidental incident that occurs within the controlled area of a nuclear facility is investigated and evaluated for necessary policy changes.

And the reason the contamination transport off-site was classified as non-emergency was because even though the amount of radiation detected on the guy is less than he'd have gotten from flying in an airplane; nuclear safety standards are so unbelievably rigorous and strict that even that small of an incident needs to be reported; even if it presents absolutely no danger to anyone anywhere (not even the guy that was contaminated) and hence is classified as a non-emergency notification.

FTA: “This is an eight-hour notification, non-emergency, for the transportation of a contaminated person offsite“

⇒ the “non-emergency” classification isn’t about the “fell into a nuclear reactor pool”, but about sending the victim off site.

> Plant officials today confirmed the worker sustained minor injuries from the fall and has already returned to work. - https://www.mlive.com/news/2025/10/michigan-nuclear-plant-wo...

They returned to work the next day with minor injuries due to the fall. It doesn't sound like it was an emergency to me.

I watched the show but if I remember correctly they actually didn’t die. They survived.

> The reality is much more positive than the myth, with all three men escaping such a grisly fate. Indeed, Alexei Ananenko and Valeri Bespalov are believed to be both still alive as of 2024, while Boris Baranov lived until 2005 when he passed away from heart disease.

Source: https://www.history.co.uk/article/the-real-story-of-the-cher...

Which do you consider as being under better control: a technology that we exhaustively create reports on even in the face of incidents like this where the only real chance of harm was that the guy couldn't swim and might have drowned; or a technology where we don't report on anything at all whatsoever and thus have no idea what's actually going on?

Reports don't mean danger, and they don't mean lack of control. Reports are information.

Did a coal miner write this comment?

We’re 50 years behind fusion because of people that now rage against fossil fuels. It’s tough to see it keep happening despite the educational resources we have now vs the 70s and 80s.

It's the reactor cavity in this case, not a nuclear waste storage pool.

Doesn’t seem like the same pool if you measure 300 counts/min from their hair afterwards.

That makes it sound like a feature! Might get some rods for my pool to keep her warm.

> You may actually receive a lower dose of radiation treading water in a spent fuel pool than walking around on the street.

Wow

Is it relevant? It's writing about a pool for storing spent fuel, which is not a part of the actual reactor system.

  This incident report says that the worker fell into a "reactor cavity" containing water and that there was a measurable amount of radiation detected in their hair after the initial clean-up. The two situations don't seem remotely compatible to me.

And a video: https://www.youtube.com/watch?v=EFRUL7vKdU8

So if I understand this correctly (solely from reading the xkcd), then the person might actually be okay?

Video format if anyone prefers it: https://youtu.be/EFRUL7vKdU8

And a video version:

https://www.youtube.com/watch?v=EFRUL7vKdU8&t=11s

This may be the most relevant xkcd yet. It answered all questions I had about this, thank you.

Did you mean “not great, not terrible” or was the change deliberate?

Proper nightmare fuel right here.

I'm interested, email me at contact@fbi.gov