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]
> dunno if the life vest bit comment of yours was sarcastic, but it is a funny remark for sure :-)
It was a quote of the linked article:
"Holtec International, which owns the closed nuclear facility, reported the worker was a contractor who was wearing all required personal protective equipment, including a life vest while working near the pool without a barrier in place."
Rather more like "Guy fell over looking into the volcano but fortunately there's a metal fence". The most immediate danger to you is that you'll drown because radioactive water is water and you can't breathe. So the life vest avoids this. In contrast volcanic lava absolutely can kill you before you drown, no problem.
Yes, radioactivity isn't good. You should not, for example, drink this water, or swim in it once a week for good luck. But, it isn't magic death fluid, the worker will have been decontaminated - destroying clothing, washing skin and so on, and the additional exposure means they might get more monitoring, but they're probably fine.
In addition to that they increased their likelihood to get cancer earlier than they would otherwise. Many things have this effect, for example alcohol. In the end everyone get cancer eventually, some just die before from
other causes.
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.
PDE5 (viagra, cyalis) improve the health of the cardiovascular system, thus improve kidney health and I greatly enjoy them.
This is well researched and just like with semaglutide I believe a big part of the population should take daily tadalafil.
Better cardiovascular health, more erections and many positive downstream effects (lower E:T ratio, weight loss) that are beyond the scope of this comment.
Better than exercise is a better normal lifestyle. Trying to compensate in an hour what went wrong most of the day or week, and with your diet, is far from optimal.
From a personal experience, so it's just a guess, a contributor may be fluid movement in the body. Fluid in blood vessels are pumped directly, but must fluid is not in blood vessels. The heart has a diminishing effect outside the vessels (capillaries have small holes to let water and small molecules through into extracellular space, and then to collect it back, rest goes through the lymphatic system which also drains back into the bloodstream). Muscle and body movement helps. From what I experienced and experimented, just walking did a lot more than running. I focus on this specifically due to personal health experiences that I don't want to go into that let me feel a clear difference, where intensive running did hardly anything but then just walking did, an experiment I performed during a period of my life when "getting stuff out from all over my body" mattered.
Personally, I choose to run only when my brain/body tell me to, when I feel like it. Definitely not when I would have to fight myself to get going. (If your body/brain tells you the opposite then it is what it is, personal feel over generic advice)
Doctors have been telling us that for decades now and still noone does it despite overwhelming evidence. I guess the average Joe will always need a cheap workaround drug rather than putting themselves at any level of physical discomfort.
Every person has a limit of how much time and energy they can put into exercise. If they can go beyond that with a pill (with no other cost), why wouldn't you want everyone to take it?
It might be empirically sound, but it does not make a priori sense that exercising a body will improve it. If I use almost any object in the universe frequently, it typically degrades rather than improves.
The health benefits of exercise are most likely due to improved blood flow and related physiological effects. In principle, pills could theoretically achieve similar outcomes by enhancing circulation or other underlying mechanisms.
> It might be empirically sound, but it does not make a priori sense that exercising a body will improve it. If I use almost any object in the universe frequently, it typically degrades rather than improves.
Rejecting all evidence, denying observations, and leaning heavily on half-baked hypothesis that culminate somehow on a gotcha. That sounds an awful lot like something someone who "does their own research" would say.
Yes, extreme levels of high-intensity exercise have adverse side effects. Cross-fit and rhadbo is an example.
Drinking water also does everyone good, and everyone's health will improve if they increase their water intake, but drinking water in excess can also be fatal. Does this mean that the idea that drinking water does you good "does not make a priori sense"?
In the context of running, physiological benefits I’m familiar with include improvements to bone density and joint health, increased capillarisation and therefore blood flow in the muscles and improved energy efficiency in cells.
I suspect you’re not going to find a pill or combination of pills that can achieve those outcomes. And again, we’re ignoring the mental health benefits.
Do you not have any negative side effects? When I tried I felt this tightness and weird headache that I don't otherwise ever experience, brain fog and also nasal symptoms.
unfortunately i was surprised that even the generic is kinda pricey to take every day. At the smallest available dose it was 5 usd a pill (last i checked in China)
I just checked my text from Walmart last week saying my
Tadalafil was ready for pickup. It was literally $25.60 for a 30 day supply of 10mg and I currently don't have insurance. 100% out of pocket.
Copying the abstract here, just in case anybody don't have access:
Emily Austin, Hilary S. Myron, Richard K. Summerbell, Constance A. Mackenzie,
Acute renal injury cause by confirmed Psilocybe cubensis mushroom ingestion,
Medical Mycology Case Reports, Volume 23, 2019, Pages 55-57, ISSN 2211-7539,
Abstract: Psilocybe mushrooms are consumed for their hallucinogenic properties. Fortunately, there are relatively few adverse effects associated with their consumption. This is the first reported case of acute kidney injury (AKI) secondary to confirmed ingestion of Psilocybe cubensis mushroom. A 15-year-old male developed symptomatic AKI 36 h post-ingestion of Psilocybe cubensis mushrooms. He was admitted to hospital with hypertension, nausea and abdominal pain and a creatinine of 450 mmol/L. A sample of the crop of mushrooms was confirmed by mass spectrometry to contain psilocin. On day 5 post-admission, he was discharged home. Outpatient follow-up confirmed complete resolution of his renal function.
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.
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.
For reference, this is about the same in your hair that you’d get from a few hours in a pub in the 90s, never mind working in one - surprising amount of radiation in cigarette smoke from polonium and lead-210.
It does say that. Can you translate that into a measurement of radioactivity & medical risk? I don't think it is obvious.
EDIT The report below it seems to literally be "nothing interesting happened". The thresholds here for something to be reportable are very low. Frankly I don't know why this story is upvoted so much but I'm not about to make a bigger deal about it than one sentence.
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.
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 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.
However, it's not nothing either. It's maybe no problem for this person only because they avoided ingesting the water and the water was very quickly washed off and presumably their hair was cut off and all clothes etc removed as fast as possible. It's clearly at least "rather hot" and you can't just play in it and have prolonged exposure and ingestion. It doesn't seem to be "basically zero".
The report doesn't read like something involving 500 rem and potential death in 3 weeks. It says "Non Emergency". Can you link to this converter? It seems to be a rather key step that got handwaved. Wiki says [0] there isn't a standard on what a "count" counts.
This website [0] gives the same numbers (300 CPM -> 500 REM). Seems like a candidate for what was used at the very least, and nothing else obviously appeared to claim a similar CPM -> REM conversion capability.
Assuming this website was used, it looks like it does a naive multiplication by 5/3, which seems... simplistic? The rest of the page doesn't exactly fill me with confidence either. No indication of how the conversion factor was derived and there's a bunch of links to other CPM -> <radiation-related unit> calculators. On top of that, the landing page for the root domain boasts about AI capabilities and their AI page prominently features "Elevate Your Content Creation" and "Generate high-quality AI content with ease!"
I'd love to know how they got to 5/3. It also offers CPM to half-life conversion which has to be at least poorly labelled. That would imply that if two piles of different radioactive substances emit the same amount of radiation (obviously different masses in each pile) they have the same half life. That isn't the case, half life depends on what the substance is which is radiating, not the measured amount of radiation emitted.
Given their CPM to half-life conversion amounts to dividing by 60 (not to mention the nonsensical units), I'm not sure I'd place much faith in the website at all.
Not necessarily nuclear (since chemical and industrial accidents are much, muhc more likely), but highly recommended if you're interested in such incidents and their causes.
> 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.
300CPM above background is considered very low - likely why they classified this as non-emergency - the only reason it was reported was per NRC cfr that states any time there is transportation of a radioactively contained person offsite, it must be notified.
For reference, in Canada, that is considered trace contamination and not dose. You would experience 300-800 CPM on a commercial airliner during the entirety of your flight, for comparison.
edit: adding to this that the site in question, Palisades, is shut-down and is under decommissioning and was not operating at the time - so while the water would have had some radioactivity due to exposure to the formerly active core, it was not like falling into an operating reactor or into moderating heavy water... also something that cannot happen with a pressurized reactor such as this one.
I thought 50-130 CPM above background was considered trace exposure. But yeah I didn't realize it was a decommissioned core... idk there are so many red flags in this story.
EDIT: 300-600 CPM above background radiation levels is for EXTERNAL environmental monitoring, not for POST-DECONTAMINATION readings on a contaminated person.
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?
I maintain the complete archive of every publication my father did from 1969 to 2019 and continue to update the archive based on new publications. I use the data to train Nuclear Radiochemistry AI Agents and while I do not have my father's credentials, I actively use this dataset to learn about his field, and from my limited knowledge here I felt the need to comment. After all, what is skepticism if we can't share and teach each other what we know, right?
> I use the data to train Nuclear Radiochemistry AI Agents and [...]
As someone who is not involved in this ongoing discussion, I have to just say that invoking LLM agents when asked for credentials is not going to go in your favor.
My use case for data that exists that is pre-AI scientifically vetted work is completely divorced from the specifics of this conversation actually. If I want to do paper-maché sculptures with printouts of these papers, and I still commented on this post, would that be better or worse for you, here?
I was just sharing background. I want to make good models that can help scientists do work. Your personal feelings about LLMs and their capabilities feels quite distinct from the focus on this post, and the chain of comments that have led us here.
So you don't have the necessary credentials, and you still wouldn't be qualified to comment even if you did have them unless you had access to the internal data. But no worries, I'm sure you'd be OK getting surgery from a surgeon's son who never went to medical school nor read your chart.
I would take the advice of a surgeons son, who is also somewhat active in the field, that something sounds fishy about a operation, to further look into it. That is very different from letting him perform the surgery.
There is incentive to play down accidents. No idea what happened here, I actually rather think it recived publicity because falling into a nuclear reactor pool sounds way more dramatic than it is, but ... not my area. Still was happy to get arthurcolle's input.
Yep you know better than the people who have the credentials you don't and the access to internal data you don't. I don't see what's holding you back from doing surgery, qualifications and context are no barrier to the application of your self-imagined expertise.
I don't claim to know better. But restarting a $1.5B plant after 2 years of inactivity and having a worker fall into a vat of radioactive water and still being at 300 CPM after a decontamination procedure is not normal.
> 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.)
> On August 31st, 2010, a diver was servicing the spent fuel pool at the Leibstadt nuclear reactor in Switzerland. He spotted an unidentified length of tubing on the bottom of the pool and radioed his supervisor to ask what to do. He was told to put it in his tool basket, which he did. Due to bubble noise in the pool, he didn’t hear his radiation alarm.
When the tool basket was lifted from the water, the room’s radiation alarms went off. The basket was dropped back in the water and the diver left the pool. The diver’s dosimeter badges showed that he’d received a higher-than-normal whole-body dose, and the dose in his right hand was extremely high.
The object turned out to be protective tubing from a radiation monitor in the reactor core, made highly radioactive by neutron flux. It had been accidentally sheared off while a capsule was being closed in 2006. It sank to a remote corner of the pool floor, where it sat unnoticed for four years.
The tubing was so radioactive that if he’d tucked it into a tool belt or shoulder bag, where it sat close to his body, he could’ve been killed. As it was, the water protected him, and only his hand—a body part more resistant to radiation than the delicate internal organs—received a heavy dose
One of my favourite bits (and a fine example of Randall's sublime humour), comes right at the end:
But just to be sure, I got in touch with a friend of mine who works at a research reactor, and asked him what he thought would happen to you if you tried to swim in their radiation containment pool.
“In our reactor?” He thought about it for a moment. “You’d die pretty quickly, before reaching the water, from gunshot wounds.”
> A CPM value means nothing without additional context
Here to confirm this. If you're googling "CPM" you'll find charts that say different things. That's why you need to read carefully. Better, just chill, it is okay that you don't know. It's nuclear physics. It's not a subject you're expected to know about.
For CPM, what matters is "CPM of <WHAT>"
CPM just tells you the number of particle detection. It does not tell you the particle type (e.g. alpha, beta, gamma) nor the energy level (i.e. eV). Without context, it is meaningless.
As an example, I can confidently say you are getting over 100bn CPM right now. The reason it doesn't matter is that this is neutrinos and they're not interacting with you[0]. 1CPM or 1e20CPM, who cares. Conversely, 1 CPM can be deadly. You definitely don't want to be hit by a single ReV (10^27) proton (good luck producing that though). Context matters.
> This is why the Sievert exists as a unit.
Which still needs context.
Sievert is joule per kilogram. So energy divided per mass, much like pressure is force over area. But determining biological impact still takes interpretation. You have weight factors by particle types (e.g. alpha = 2x beta) and there is also weighting factor for internal/external dose and locations like soft tissue (e.g. higher weighting for dose at throat vs dose at hands).
This is why it is incredibly important to use caution when interpreting radiation values. If you don't have training in this it is incredibly easy to unknowingly make major errors. The little details can dramatically change the outcome. Context is critical.
I'm not here to tell you how to actually do the calculation (you'll need a lot more info), I'm here to tell you that it's not easy and you're likely doing it wrong. The experts are not dumb. You're just missing context and a first order approximation is nowhere near enough for an accurate conclusion. It's nuclear physics lol
It shouldn't need be said, but nuclear physics is, in fact, complicated.
> [Y]ou are getting over 100bn CPM right now. The reason it doesn't matter is that this is neutrinos and they're not interacting with you.
I mean, if you actually had a neutrino detector that produced 10e10 CPM over your cross-section, then it would matter for you, because particle physicists would kidnap you to learn the secret :)
Honestly, the military would probably come after you first. Or maybe an oil company? Frankly because if you could detect neutrinos at that resolution you would be able to produce a really good mapping of... just about anything. From the inside of the Earth to the inside of a secret military facility on the opposite side of the planet. Not to mention you've also invented a communication device that is essentially unjammable[0].
Sufficient to say that you'd be very popular, but in probably the least fun way possible.
Thank you for the followup (familiar with the XKCD)
Dumb question from a true non-expert:
So CPM varies with all those factors you mention, but wouldn't the site HP team know exactly what detector they used, the geometry, distance, etc.? They could convert to dose if they wanted, right?
Why report the ambiguous "300 CPM" instead of an actual dose estimate in mSv/μSv? Seems like that would be more useful for any medical team, any set of potential regulators or regulatory bodies as well as just general public understanding (drawing on my father's work here as he always emphasized the tension between "public fears radiation unnecessarily" and "industry safety protocols are inconsistent")
Follow-up: Is there any legitimate reason to report CPM instead of dose after a contamination event? Or does staying with CPM keep things conveniently vague?
Because from my limited understanding, if they did a proper survey, they have everything needed to calculate dose.
> Why report the ambiguous "300 CPM" instead of an actual dose estimate in mSv/μSv?
It is a technical document. It is meant to communicate between experts, not to the public.
> Is there any legitimate reason to report CPM instead of dose after a contamination event?
It's not nefarious, it is the measurement that they had. CPM is an easier measurement to get. And keep in mind that these notices are just a small part of the communication going on. They're meant to be brief.
To get the actual effective dosage you'll need a lot more information and calculations. The CPM can give you a decent estimate, if you already know context, but it is meaningless if you don't. So to an expert in that space it's a good quick estimate, but to an average person it isn't (even to above average people).
In context is also being used as a stepping stone for quick evaluation. They sent the guy to the hospital and he'll get a better estimate of dosage there. I'm sure they also were doing those calculations prior to sending him out. It may just be customary to use CPM units. That part I don't know. Here's the page they reference though[0] (there's only a single (xii) so easy to find).
[disclosure] I have training in nuclear physics, including in radiation dosages (I worked on developing shielding materials), but I have not worked on a reactor (though I've seen reactors and Cherenkov Radiation :) so the customs of the bureaucracy are beyond my wheelhouse. But from my experience I'm not surprised by this. I would expect a lot more documentation and accurate measurements are being passed through other channels.
Looking at these bulletins, they appear to be quick summaries of pretty much any nuclear related incident that happens in the US, no matter how minor. I would assume that these are mostly intended for public transparency, and as for a quick reference point for regulatory action. Introductory slide on a PowerPoint sort of material.
In that context, I'd guess that the 300 CPM figure is just a signpost that says "we measured the worker to make sure that he was safe to release to a hospital."
Is the information intended to be given out to the public in a manner in which the general public can interpret? No. It's encoded lol. But you can hear that on the radio and if you're trained (could go to a public library to train yourself) and yeah it makes sense. It is specifically intended to be concise and communicate only the absolute minimum amount of necessary information.
For another example, look at arXiv. Is it public? Yes. Are the papers published there written for the general public? No. They are written for peers.
So yes, it is "public transparency", but not for transparency to people who aren't train in nuclear physics. (Which is what I previously said)
>Is there any legitimate reason to report CPM instead of dose after a contamination event?
Basically, the procedures for certain environments differ. If you want to gather dosage data, you use a dosimeter. If you want a binary Yes/No method of detecting contamination, you use a geiger counter and determine if the count rate is above a certain range (depending on background radiation and other factors).
The 300CPM metric just indicates whether they're clean or not after they've been scrubbed down. It doesn't measure the dose they took.
I would imagine the on-site team would know, yes. I don't know why the report only gives a measurement in CPM, but just because the person was sent off-site doesn't mean the levels were dangerous. Thresholds at nuclear facilities tend to be very low for safety.
The USNRC is currently not operating normally due to the government shutdown. Perhaps that has something to do with it.
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.
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!
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....
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.
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".
Townsville's Strand has a number of them for example. (Really bad lighting, but I believe it's that green board: https://maps.app.goo.gl/x7gggCjGwxVqDBx79?g_st=ac) I went down the Qld coast a couple of weeks ago and they're still very common.
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.
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.
They bite (and suck) with their (elongated and specialized) mouthparts. Insects don’t have noses (they breathe through their skin and smell primarily with their antennae).
Oh I thought I couldn't hate them anymore and I learn this. My leg currently has large hives on it from multiple bites, the antihistamines I have are doing bugger all.
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.
I heard a story from colleagues when working at a foundry of a guy falling into a vessel that had previously held molten metal. It was empty but still red hot inside. He fell front a small cavity on the top when doing some clean up work. They heard him scream for about a minute.
Why didn't they shave off the hair and measure again before sending off to medical? They have the opportunity to report lower numbers, and would enable identifying non-hair-adsorbed radiatioactive matter on the subject. It sounds so easy and actionable it boggles the mind that it's not part of the protocol.
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.
“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
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.
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.
You describe incidents which become political. At some point the normal rules are being ignored by those on the top of the information food chain. That says nothing about the rules of the game, but does say a lot about the people involved.
> What if I took a swim in a typical spent nuclear fuel pool? Would I need to dive to actually experience a fatal amount of radiation? How long could I stay safely at the surface?
> Assuming you’re a reasonably good swimmer, you could probably survive treading water anywhere from 10 to 40 hours. At that point, you would black out from fatigue and drown. This is also true for a pool without nuclear fuel in the bottom.
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?
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.
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.
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?
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?
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.
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?
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).
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.
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.
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.
> They had 300 counts per minute which would e around 6200 mSv year
Are you sure about that? 6200 mSv is 6.2 Sv, which I understand to be near-universally deadly. That dosage would be profoundly incompatible with the news that the worker was being sent offsite to seek non-emergency medical attention.
Poking around, it looks like "counts per minute" have to get converted to a dosage using an instrument-specific formula. I CBA to go find that formula, but you're quite welcome to.
Rate matters. 6.2Sv in a single hour is fatal. 6.2Sv in a single year is probably less than average for a human from background radiation. The measurement units for ionizing radiation are very complicated and confusing. That's why people are told to not try to compute this stuff yourself. I have code that computes these units and conversions, its not simple. Here is a brief and simplified explanation of how you calculate this stuff.
There are 4 types of ionizing radiation: alpha, beta, gamma/x-rays and neutron flux. Each one has a different rate it is blocked by different materials (water, air, etc). Each one has a different risk to people. You have to compute counts per unit time emitted from a point source for each of the different types of radiation. Then you have to compute the amount of "arc" the person is in. Then you have counts being absorbed and you next multiply each count by a fixed factor depending on the type of radiation. This final number gives you total Greys per unit time, then you then have to divide by the mass of the person. Then you multiple that number by the total amount of time and that gives you total Greys absorbed. That's the number you use to assess risk to the person. For reference, this guy probably got less than 1 Grey. Someone getting radiation treatment for cancer might get 75 Greys.
So please stop trying to calculate this stuff yourself. I'm pretty sure you are doing it wrong. This guy will be fine.
PS Sieverts are a physical measure, Greys are a measure of biological "harm".
> PS Sieverts are a physical measure, Greys are a measure of biological "harm".
The US's NRC disagrees with you. From [0], they say this about the sievert and rem:
Dose equivalent
A measure of the biological damage to living tissue as a result of radiation exposure. Also known as the " biological dose," the dose equivalent is calculated as the product of absorbed dose in tissue multiplied by a quality factor and then sometimes multiplied by other necessary modifying factors at the location of interest. The dose equivalent is expressed numerically in rems or sieverts (Sv) (see 10 CFR 20.1003). For additional information, see Doses in Our Daily Lives and Measuring Radiation.
and have this to say about the gray:
Dose, absorbed
The amount of energy absorbed by an object or person per unit mass. Known as the “absorbed dose,” this reflects the amount of energy that ionizing radiation sources deposit in materials through which they pass, and is measured in units of radiation-absorbed dose (rad). The related international system unit is the gray (Gy), where 1 Gy is equivalent to 100 rad. For additional information, see Doses in Our Daily Lives and Measuring Radiation.
Grays seem to be "amount of radiation absorbed per kg". Looking further, the "Measuring Radiation" page at [1] directly contradicts your claim. Speaking about rems and Svs, it says:
Dose equivalent (or effective dose) combines the amount of radiation absorbed and the medical effects of that type of radiation. For beta and gamma radiation, the dose equivalent is the same as the absorbed dose. By contrast, the dose equivalent is larger than the absorbed dose for alpha and neutron radiation, because these types of radiation are more damaging to the human body.
I'm definitely not an expert, but the NRC is pretty official, and their explanations sound pretty clear to me. Is what they're saying here incorrect?
> 6.2Sv in a single year is probably less than average for a human from background radiation.
Are you sure about that? <https://xkcd.com/radiation/> claims 4 mSv per year as normal radiation dosage, and 50 mSv per year as maximum permitted annual dosage for "US radiation workers", whatever that means.
I think you're off by a factor of a thousand for the typical exposure level and off by a factor of a hundred for the exposure level where they stop letting you work near the radioactives for a year.
no not sure. yeah I used the an average instrument specific rate. The point is a) everything emits, b) we have no idea on severity from the info, could be a little, could be a lot. Could also be short term (haircut) or longer term (ingested) exposures.
> yeah I used the an average instrument specific rate.
Would you provide a link to the source of this average instrument specific rate?
I'm interested in knowing which instruments designed to detect low-to-medium-level radiation sources on a human are configured so that five detections per second would equate to a "You're fucking dead; there's really no hope for you" dose.
(Did you ask an LLM to "convert counts per minute to mSv" and fail to sanity-check the confident-sounding result it gave you?)
> ...everything emits...
Given that the crust and sea and air of this planet are chock full of radioactives, and that every living thing on the planet builds itself out of that material, that goes without saying.
You need a device that can measure the different types of radiation. Then you have to do a bunch of calculations to estimate absorption. Only then can you calculate Greys which is the measurement that matters.
PS 300 CPM is nothing. There are places where people live where the natural background radiation is higher than that. Also, background radiation is mostly Gamma rays which is more dangerous than what comes off of fission products or nuclear fuel.
Hair can't hold that much water compared to any ingested amount. Whether contaminated or activated, internal irradiation from that much will be pretty bad.
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 the feeling that you don't know how complicated calculating radiation exposure is. There are plenty of interest in fear mongering against nuclear. Almost all the people talking about how much radiation 300 CPM is have absolutely no idea what they are talking about. Some confuse total measurement units for rates; others are using just the wrong units; still others are talking about levels that are 1000x or 1000000x higher than 300 CPM.
Or to put it another way, 300 CPM (which is a rate) is less than how much radiation you get when on a flight, or how much radiation you get at higher elevations. Even giving a simple explanation of how to calculate Greys (the actual measure you are looking for) takes up the better part of a page. Hell, your bones are radioactive. Yet there are plenty of people posting that somehow the risk to this guy is radioactivity. In reality, his biggest problem is probably going to be finding a new job.
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.
Huh why not. It's far less dangerous than, say, a train station or a viewpoint where everyone can just jump and die. Many reactors are open for kids and class trips where everyone can stare into a reactor
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.
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.
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)
There is a deeper point here, not just pedantry. The point is that harm is a spectrum not a binary and one cannot meaningfully answer a question that assumes a binary.
Personally, my belief in my own immortality only increases the older I get. Yes, Socrates died, but he clearly wasn't smart if he died. Me, on the other hand? I'm batting a thousand.
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.
Hopefully the worker is okay. I have to agree that the non-emergency classification seems odd. This should warrant a proper investigation and steps to avoid this in the future.
I thought you could safely swim in that water so long as you stay a few meters clear of the rods? water being a good absorber of radiation and all. Is this just a precautionary reaction?
Scrolling up and down the list, just how onerous is this reporting regulation? It seems almost cartoonishly excessive, even for critical safety applications.
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.
> Sea-drilling rigs (oil) have far more potential for environmental damage than modern nuclear plants
Key word: "modern". A key aspect of a modern nuclear plant, that supports its high level of safety, is the required incident reporting and followup.
The relevant issue is not really about a single worker being injured or dying. It's about detecting safety issues which could lead to a catastrophe far beyond what a sea oil drilling rig can, at least when it comes to human life and habitability of the surrounding area.
For example, after Chernobyl, much of Europe had to deal with contamination from cesium 137.
The entire planet's geological history shows when the nuclear age started, because humans are irresponsible in aggregate. (See also global warming.)
> Aaaand it’s this alarmist attitude ...
You're providing an object lesson in why humans can't really be trusted to operate systems like this over the long term.
> You're providing an object lesson in why humans can't really be trusted to operate systems like this over the long term.
Ironically so are you. The coal we burn puts far more radioactivity into the environment than nuclear plants do. Yet we make sure nuclear isn't viable and burn coal like crazy. We do this only because of the type of risk telescoping you are doing. If you do a rational risk assessment, you will see that even operating nuclear plants as shown in the Simpsons would have less risk than what we are doing now. There is a risk to doing nothing. You are missing that part in your assessment.
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.
Not really hard: nuclear power generation uses radiation and radioactive material, but tries very hard not to release it. Coal power generation burns a substance that contains a small amount of radioactive material, and makes no effort not to release radiation.
It's not that surprising. We're burning a rock we dug out of the ground and turning it into a vapor. Rocks found underground contain some amount of natural radioactive material, for example granite/marble tend to be higher in radiation. If you burn that into a powder and put it into the atmosphere it'll spread around and expose the nearby area to very slightly radioactive pollution.
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.
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.
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
"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.
They keep the water in an LWR pretty clean to avoid corrosion problems. Thing is the slightest almost of tritium in the water will light up a portal detector like a pinball machine on tilt.
Man in Michigan potentially exposed to radiation levels equivalent to undergoing 4 x-rays at the doctors office.
Meanwhile, in Texas, 1.5 people die every day working in Oil and Gas extraction.
A few people die every year installing or falling off of wind turbines.
But by all means, let's make this a news story instead and keep making nuclear sound scary. I’m sure the person who posted this to HN with this clickbait title has zero political beliefs.
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.
I find it highly informative that the required PPE for working in that location is a life jacket so you float in case you fall in, rather than a tether and fall arrest harness so that it's not possible to fall in.
300 CPM is nothing, background levels might be 150.
Background is probably a bit lower depending on where you're at. My counter went through airport security luggage scans 'cause they wouldn't let me wear it through the metal detector. It beeps for a few seconds and then comes out about a days' dose of natural radiation higher. The count was higher than 300 CPM, but obviously only shortly.
That poor bloke might stay at 300 (if ingested and he can't scrub it off) for a while but it's still not very discouraging long-term. Pilots have about that at cruising altitude.
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...
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"
> dunno if the life vest bit comment of yours was sarcastic, but it is a funny remark for sure :-)
It was a quote of the linked article:
"Holtec International, which owns the closed nuclear facility, reported the worker was a contractor who was wearing all required personal protective equipment, including a life vest while working near the pool without a barrier in place."
My understanding is that reactor and waste pools are some of the least radioactive environments as they are constantly monitored for leakage.
Rather more like "Guy fell over looking into the volcano but fortunately there's a metal fence". The most immediate danger to you is that you'll drown because radioactive water is water and you can't breathe. So the life vest avoids this. In contrast volcanic lava absolutely can kill you before you drown, no problem.
Yes, radioactivity isn't good. You should not, for example, drink this water, or swim in it once a week for good luck. But, it isn't magic death fluid, the worker will have been decontaminated - destroying clothing, washing skin and so on, and the additional exposure means they might get more monitoring, but they're probably fine.
In addition to that they increased their likelihood to get cancer earlier than they would otherwise. Many things have this effect, for example alcohol. In the end everyone get cancer eventually, some just die before from other causes.
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.
FYI:
Fuck me, is there anything fun that isn't nephrotoxic?
Menu tonight is neurotoxic or nephrotoxic
PDE5 (viagra, cyalis) improve the health of the cardiovascular system, thus improve kidney health and I greatly enjoy them.
This is well researched and just like with semaglutide I believe a big part of the population should take daily tadalafil.
Better cardiovascular health, more erections and many positive downstream effects (lower E:T ratio, weight loss) that are beyond the scope of this comment.
What about migraines though? Or do you keep the dose low enough to avoid that?
People should probably try improve their CV health via exercise, rather than pills, wherever possible.
Better than exercise is a better normal lifestyle. Trying to compensate in an hour what went wrong most of the day or week, and with your diet, is far from optimal.
One of many, looking at just one detail (sitting): https://www.health.harvard.edu/staying-healthy/sitting-may-i...
From a personal experience, so it's just a guess, a contributor may be fluid movement in the body. Fluid in blood vessels are pumped directly, but must fluid is not in blood vessels. The heart has a diminishing effect outside the vessels (capillaries have small holes to let water and small molecules through into extracellular space, and then to collect it back, rest goes through the lymphatic system which also drains back into the bloodstream). Muscle and body movement helps. From what I experienced and experimented, just walking did a lot more than running. I focus on this specifically due to personal health experiences that I don't want to go into that let me feel a clear difference, where intensive running did hardly anything but then just walking did, an experiment I performed during a period of my life when "getting stuff out from all over my body" mattered.
Personally, I choose to run only when my brain/body tell me to, when I feel like it. Definitely not when I would have to fight myself to get going. (If your body/brain tells you the opposite then it is what it is, personal feel over generic advice)
Doctors have been telling us that for decades now and still noone does it despite overwhelming evidence. I guess the average Joe will always need a cheap workaround drug rather than putting themselves at any level of physical discomfort.
Lazy people will be lazy, whatever nasty side effect it brings down the line. These days they will also 'brag' about it online.
Why not both?
Every person has a limit of how much time and energy they can put into exercise. If they can go beyond that with a pill (with no other cost), why wouldn't you want everyone to take it?
Sure, but let’s start with promoting the 90 percenter rather than the 1 percenter then.
Why?
Because of all the other physiological and mental benefits that come from the exercise that the pill won’t give you?
It might be empirically sound, but it does not make a priori sense that exercising a body will improve it. If I use almost any object in the universe frequently, it typically degrades rather than improves.
The health benefits of exercise are most likely due to improved blood flow and related physiological effects. In principle, pills could theoretically achieve similar outcomes by enhancing circulation or other underlying mechanisms.
Not taking sides here, just reasoning out loud.
> It might be empirically sound, but it does not make a priori sense that exercising a body will improve it. If I use almost any object in the universe frequently, it typically degrades rather than improves.
Rejecting all evidence, denying observations, and leaning heavily on half-baked hypothesis that culminate somehow on a gotcha. That sounds an awful lot like something someone who "does their own research" would say.
Yes, extreme levels of high-intensity exercise have adverse side effects. Cross-fit and rhadbo is an example.
https://en.wikipedia.org/wiki/Rhabdomyolysis
Drinking water also does everyone good, and everyone's health will improve if they increase their water intake, but drinking water in excess can also be fatal. Does this mean that the idea that drinking water does you good "does not make a priori sense"?
No, it doesn't.
In the context of running, physiological benefits I’m familiar with include improvements to bone density and joint health, increased capillarisation and therefore blood flow in the muscles and improved energy efficiency in cells.
I suspect you’re not going to find a pill or combination of pills that can achieve those outcomes. And again, we’re ignoring the mental health benefits.
Do you not have any negative side effects? When I tried I felt this tightness and weird headache that I don't otherwise ever experience, brain fog and also nasal symptoms.
unfortunately i was surprised that even the generic is kinda pricey to take every day. At the smallest available dose it was 5 usd a pill (last i checked in China)
I just checked my text from Walmart last week saying my Tadalafil was ready for pickup. It was literally $25.60 for a 30 day supply of 10mg and I currently don't have insurance. 100% out of pocket.
shrooms
think again
https://www.sciencedirect.com/science/article/pii/S221175391...
Copying the abstract here, just in case anybody don't have access:
Emily Austin, Hilary S. Myron, Richard K. Summerbell, Constance A. Mackenzie, Acute renal injury cause by confirmed Psilocybe cubensis mushroom ingestion,
Medical Mycology Case Reports, Volume 23, 2019, Pages 55-57, ISSN 2211-7539,
https://doi.org/10.1016/j.mmcr.2018.12.007. (https://www.sciencedirect.com/science/article/pii/S221175391...)
Abstract: Psilocybe mushrooms are consumed for their hallucinogenic properties. Fortunately, there are relatively few adverse effects associated with their consumption. This is the first reported case of acute kidney injury (AKI) secondary to confirmed ingestion of Psilocybe cubensis mushroom. A 15-year-old male developed symptomatic AKI 36 h post-ingestion of Psilocybe cubensis mushrooms. He was admitted to hospital with hypertension, nausea and abdominal pain and a creatinine of 450 mmol/L. A sample of the crop of mushrooms was confirmed by mass spectrometry to contain psilocin. On day 5 post-admission, he was discharged home. Outpatient follow-up confirmed complete resolution of his renal function.
Keywords: Psilocybe; Nephrotoxicity; Mushrooms; Kidney injury
Sounds like it was a lot more serious for the water than for the worker
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.
Then where did their radioactive hair come from?
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.
It says "The individual was decontaminated by radiation protection personnel but had 300 counts per minute detected in their hair."
For reference, this is about the same in your hair that you’d get from a few hours in a pub in the 90s, never mind working in one - surprising amount of radiation in cigarette smoke from polonium and lead-210.
It does say that. Can you translate that into a measurement of radioactivity & medical risk? I don't think it is obvious.
EDIT The report below it seems to literally be "nothing interesting happened". The thresholds here for something to be reportable are very low. Frankly I don't know why this story is upvoted so much but I'm not about to make a bigger deal about it than one sentence.
300cpm is lower than what you’d be exposed to on a commercial airline flight (400-900ish cpm).
But is that the same thing? 300cpm says something about the risk to someone near the worker, not about what the worker has been exposed to
CPM is a function of the detector sensitivity/size and radiation level.
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:
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 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.
However, it's not nothing either. It's maybe no problem for this person only because they avoided ingesting the water and the water was very quickly washed off and presumably their hair was cut off and all clothes etc removed as fast as possible. It's clearly at least "rather hot" and you can't just play in it and have prolonged exposure and ingestion. It doesn't seem to be "basically zero".
What does it mean for airline pilots? From what I read, they are exposed to more than 400 CPM thought the year.
Stewardesses become infertile earlier than women working on the ground.
The report doesn't read like something involving 500 rem and potential death in 3 weeks. It says "Non Emergency". Can you link to this converter? It seems to be a rather key step that got handwaved. Wiki says [0] there isn't a standard on what a "count" counts.
[0] https://en.wikipedia.org/wiki/Counts_per_minute
This website [0] gives the same numbers (300 CPM -> 500 REM). Seems like a candidate for what was used at the very least, and nothing else obviously appeared to claim a similar CPM -> REM conversion capability.
Assuming this website was used, it looks like it does a naive multiplication by 5/3, which seems... simplistic? The rest of the page doesn't exactly fill me with confidence either. No indication of how the conversion factor was derived and there's a bunch of links to other CPM -> <radiation-related unit> calculators. On top of that, the landing page for the root domain boasts about AI capabilities and their AI page prominently features "Elevate Your Content Creation" and "Generate high-quality AI content with ease!"
[0]: https://www.inayam.co/unit-converter/radioactivity/counts_pe...
I'd love to know how they got to 5/3. It also offers CPM to half-life conversion which has to be at least poorly labelled. That would imply that if two piles of different radioactive substances emit the same amount of radiation (obviously different masses in each pile) they have the same half life. That isn't the case, half life depends on what the substance is which is radiating, not the measured amount of radiation emitted.
Given their CPM to half-life conversion amounts to dividing by 60 (not to mention the nonsensical units), I'm not sure I'd place much faith in the website at all.
Water itself is activated by neutrons, even if slightly.
The Uranium Isotopes would also not be that terrible. It's the fission products that get you.
The Chemical Safety and Hazard Investigation Board has a great YouTube channel where they carefully analyze similar accidents.
https://www.youtube.com/@USCSB/videos
Not necessarily nuclear (since chemical and industrial accidents are much, muhc more likely), but highly recommended if you're interested in such incidents and their causes.
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.
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?
300CPM above background is considered very low - likely why they classified this as non-emergency - the only reason it was reported was per NRC cfr that states any time there is transportation of a radioactively contained person offsite, it must be notified.
For reference, in Canada, that is considered trace contamination and not dose. You would experience 300-800 CPM on a commercial airliner during the entirety of your flight, for comparison.
edit: adding to this that the site in question, Palisades, is shut-down and is under decommissioning and was not operating at the time - so while the water would have had some radioactivity due to exposure to the formerly active core, it was not like falling into an operating reactor or into moderating heavy water... also something that cannot happen with a pressurized reactor such as this one.
I thought 50-130 CPM above background was considered trace exposure. But yeah I didn't realize it was a decommissioned core... idk there are so many red flags in this story.
EDIT: 300-600 CPM above background radiation levels is for EXTERNAL environmental monitoring, not for POST-DECONTAMINATION readings on a contaminated person.
I learned a few things from my father along the way. I can share my notes if you'd like
https://en.wikipedia.org/wiki/Ronald_Coll%C3%A9?wprov=sfti1
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?
I maintain the complete archive of every publication my father did from 1969 to 2019 and continue to update the archive based on new publications. I use the data to train Nuclear Radiochemistry AI Agents and while I do not have my father's credentials, I actively use this dataset to learn about his field, and from my limited knowledge here I felt the need to comment. After all, what is skepticism if we can't share and teach each other what we know, right?
https://github.com/arthurcolle/Ronald-Colle-Papers
I love how punchy you are! And the astronomy photos. Take care :)
> I use the data to train Nuclear Radiochemistry AI Agents and [...]
As someone who is not involved in this ongoing discussion, I have to just say that invoking LLM agents when asked for credentials is not going to go in your favor.
My use case for data that exists that is pre-AI scientifically vetted work is completely divorced from the specifics of this conversation actually. If I want to do paper-maché sculptures with printouts of these papers, and I still commented on this post, would that be better or worse for you, here?
I was just sharing background. I want to make good models that can help scientists do work. Your personal feelings about LLMs and their capabilities feels quite distinct from the focus on this post, and the chain of comments that have led us here.
So you don't have the necessary credentials, and you still wouldn't be qualified to comment even if you did have them unless you had access to the internal data. But no worries, I'm sure you'd be OK getting surgery from a surgeon's son who never went to medical school nor read your chart.
I would take the advice of a surgeons son, who is also somewhat active in the field, that something sounds fishy about a operation, to further look into it. That is very different from letting him perform the surgery.
There is incentive to play down accidents. No idea what happened here, I actually rather think it recived publicity because falling into a nuclear reactor pool sounds way more dramatic than it is, but ... not my area. Still was happy to get arthurcolle's input.
But I am not doing surgery. I am expressing skepticism at the "oh no it's all fine" from literally everyone reporting on this story
You're being unnecessarily attacked for what is largely a casual forum where people make casual comments and speculation all of the time.
Further, your reasoning is biased towards safety (rather than risk), which seems completely sane.
Agreed. These violent reactions aren’t unusual for HN but they are unnecessary and acutely disappointing.
Yep you know better than the people who have the credentials you don't and the access to internal data you don't. I don't see what's holding you back from doing surgery, qualifications and context are no barrier to the application of your self-imagined expertise.
I don't claim to know better. But restarting a $1.5B plant after 2 years of inactivity and having a worker fall into a vat of radioactive water and still being at 300 CPM after a decontamination procedure is not normal.
That'd be a very interesting statement if you were qualified to make it
> Collé and his collaborators have maintained, expanded and improved radioactivity measurement standards...
Story checks out. I think this would pass.
Quantify? What kind of number would satisfy your request?
> 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/
From the what if:
> On August 31st, 2010, a diver was servicing the spent fuel pool at the Leibstadt nuclear reactor in Switzerland. He spotted an unidentified length of tubing on the bottom of the pool and radioed his supervisor to ask what to do. He was told to put it in his tool basket, which he did. Due to bubble noise in the pool, he didn’t hear his radiation alarm.
When the tool basket was lifted from the water, the room’s radiation alarms went off. The basket was dropped back in the water and the diver left the pool. The diver’s dosimeter badges showed that he’d received a higher-than-normal whole-body dose, and the dose in his right hand was extremely high.
The object turned out to be protective tubing from a radiation monitor in the reactor core, made highly radioactive by neutron flux. It had been accidentally sheared off while a capsule was being closed in 2006. It sank to a remote corner of the pool floor, where it sat unnoticed for four years.
The tubing was so radioactive that if he’d tucked it into a tool belt or shoulder bag, where it sat close to his body, he could’ve been killed. As it was, the water protected him, and only his hand—a body part more resistant to radiation than the delicate internal organs—received a heavy dose
I love this book. Randall is such a gifted artist
One of my favourite bits (and a fine example of Randall's sublime humour), comes right at the end:
But just to be sure, I got in touch with a friend of mine who works at a research reactor, and asked him what he thought would happen to you if you tried to swim in their radiation containment pool.
“In our reactor?” He thought about it for a moment. “You’d die pretty quickly, before reaching the water, from gunshot wounds.”
For CPM, what matters is "CPM of <WHAT>"
CPM just tells you the number of particle detection. It does not tell you the particle type (e.g. alpha, beta, gamma) nor the energy level (i.e. eV). Without context, it is meaningless.
As an example, I can confidently say you are getting over 100bn CPM right now. The reason it doesn't matter is that this is neutrinos and they're not interacting with you[0]. 1CPM or 1e20CPM, who cares. Conversely, 1 CPM can be deadly. You definitely don't want to be hit by a single ReV (10^27) proton (good luck producing that though). Context matters.
Which still needs context.Sievert is joule per kilogram. So energy divided per mass, much like pressure is force over area. But determining biological impact still takes interpretation. You have weight factors by particle types (e.g. alpha = 2x beta) and there is also weighting factor for internal/external dose and locations like soft tissue (e.g. higher weighting for dose at throat vs dose at hands).
This is why it is incredibly important to use caution when interpreting radiation values. If you don't have training in this it is incredibly easy to unknowingly make major errors. The little details can dramatically change the outcome. Context is critical.
I'm not here to tell you how to actually do the calculation (you'll need a lot more info), I'm here to tell you that it's not easy and you're likely doing it wrong. The experts are not dumb. You're just missing context and a first order approximation is nowhere near enough for an accurate conclusion. It's nuclear physics lol
It shouldn't need be said, but nuclear physics is, in fact, complicated.
[0] https://neutrinos.fnal.gov/faqs/
> [Y]ou are getting over 100bn CPM right now. The reason it doesn't matter is that this is neutrinos and they're not interacting with you.
I mean, if you actually had a neutrino detector that produced 10e10 CPM over your cross-section, then it would matter for you, because particle physicists would kidnap you to learn the secret :)
Honestly, the military would probably come after you first. Or maybe an oil company? Frankly because if you could detect neutrinos at that resolution you would be able to produce a really good mapping of... just about anything. From the inside of the Earth to the inside of a secret military facility on the opposite side of the planet. Not to mention you've also invented a communication device that is essentially unjammable[0].
Sufficient to say that you'd be very popular, but in probably the least fun way possible.
[0] https://arxiv.org/abs/1203.2847
Thank you for the followup (familiar with the XKCD)
Dumb question from a true non-expert:
So CPM varies with all those factors you mention, but wouldn't the site HP team know exactly what detector they used, the geometry, distance, etc.? They could convert to dose if they wanted, right?
Why report the ambiguous "300 CPM" instead of an actual dose estimate in mSv/μSv? Seems like that would be more useful for any medical team, any set of potential regulators or regulatory bodies as well as just general public understanding (drawing on my father's work here as he always emphasized the tension between "public fears radiation unnecessarily" and "industry safety protocols are inconsistent")
Follow-up: Is there any legitimate reason to report CPM instead of dose after a contamination event? Or does staying with CPM keep things conveniently vague? Because from my limited understanding, if they did a proper survey, they have everything needed to calculate dose.
To get the actual effective dosage you'll need a lot more information and calculations. The CPM can give you a decent estimate, if you already know context, but it is meaningless if you don't. So to an expert in that space it's a good quick estimate, but to an average person it isn't (even to above average people).
In context is also being used as a stepping stone for quick evaluation. They sent the guy to the hospital and he'll get a better estimate of dosage there. I'm sure they also were doing those calculations prior to sending him out. It may just be customary to use CPM units. That part I don't know. Here's the page they reference though[0] (there's only a single (xii) so easy to find).
[0] https://www.nrc.gov/reading-rm/doc-collections/cfr/part050/p...
[disclosure] I have training in nuclear physics, including in radiation dosages (I worked on developing shielding materials), but I have not worked on a reactor (though I've seen reactors and Cherenkov Radiation :) so the customs of the bureaucracy are beyond my wheelhouse. But from my experience I'm not surprised by this. I would expect a lot more documentation and accurate measurements are being passed through other channels.
Looking at these bulletins, they appear to be quick summaries of pretty much any nuclear related incident that happens in the US, no matter how minor. I would assume that these are mostly intended for public transparency, and as for a quick reference point for regulatory action. Introductory slide on a PowerPoint sort of material.
In that context, I'd guess that the 300 CPM figure is just a signpost that says "we measured the worker to make sure that he was safe to release to a hospital."
I think you're over interpreting. Publicly available doesn't mean "for the general public"
Here, take METAR as an example. This is broadcast on open airwaves and every pilot can read this. Here's the latest one from KSFO[0]
Is this public? YesIs the information intended to be given out to the public in a manner in which the general public can interpret? No. It's encoded lol. But you can hear that on the radio and if you're trained (could go to a public library to train yourself) and yeah it makes sense. It is specifically intended to be concise and communicate only the absolute minimum amount of necessary information.
For another example, look at arXiv. Is it public? Yes. Are the papers published there written for the general public? No. They are written for peers.
So yes, it is "public transparency", but not for transparency to people who aren't train in nuclear physics. (Which is what I previously said)
Don't confuse "public" with "for you"
[0] https://aviationweather.gov/data/metar/?ids=KSFO
>Is there any legitimate reason to report CPM instead of dose after a contamination event?
Basically, the procedures for certain environments differ. If you want to gather dosage data, you use a dosimeter. If you want a binary Yes/No method of detecting contamination, you use a geiger counter and determine if the count rate is above a certain range (depending on background radiation and other factors).
The 300CPM metric just indicates whether they're clean or not after they've been scrubbed down. It doesn't measure the dose they took.
I would imagine the on-site team would know, yes. I don't know why the report only gives a measurement in CPM, but just because the person was sent off-site doesn't mean the levels were dangerous. Thresholds at nuclear facilities tend to be very low for safety.
The USNRC is currently not operating normally due to the government shutdown. Perhaps that has something to do with it.
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.
GBq is also a measure of rate; it's a billion decays per second.
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
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!
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....
Palisades was closed down 2022, but just reopened recently at August 27, 2025.
Hair contaminated
> 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"
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.
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...
Just fyi, they don't put vinegars at the beaches anymore, apparently it makes it worse (well I haven't seen any for a long while)
https://www.abc.net.au/news/2014-04-08/vinegar-makes-box-jel...
Townsville's Strand has a number of them for example. (Really bad lighting, but I believe it's that green board: https://maps.app.goo.gl/x7gggCjGwxVqDBx79?g_st=ac) I went down the Qld coast a couple of weeks ago and they're still very common.
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.
Oceans are dangerous, but it's the water that's most likely to get you, even in Australia.
If you ever become prime Minister of Australia, and find yourself on an oceanside bombing range, don't go spear fishing.
Hahaha eeesh that 2nd sentence took a turn
Nah this is literally just not an emergency. The water isn't very radioactive.
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.
Or how Brits call a civil war "trouble"
We’re not that flippant, they’re ‘troubles’, indicating ’ongoing concern’.
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.
Spiders bite. I've never heard it called anything else.
Mosquitos bite with their nose.
They bite (and suck) with their (elongated and specialized) mouthparts. Insects don’t have noses (they breathe through their skin and smell primarily with their antennae).
Oh I thought I couldn't hate them anymore and I learn this. My leg currently has large hives on it from multiple bites, the antihistamines I have are doing bugger all.
and blackflies/moshka just eat you
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.
i mean it might be a medical emergency but not a reactor emergency?
I heard a story from colleagues when working at a foundry of a guy falling into a vessel that had previously held molten metal. It was empty but still red hot inside. He fell front a small cavity on the top when doing some clean up work. They heard him scream for about a minute.
Proper nightmare fuel right here.
Why didn't they shave off the hair and measure again before sending off to medical? They have the opportunity to report lower numbers, and would enable identifying non-hair-adsorbed radiatioactive matter on the subject. It sounds so easy and actionable it boggles the mind that it's not part of the protocol.
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.
“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
That happens all the time; it's only news when something unusual happens.
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.
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.
You describe incidents which become political. At some point the normal rules are being ignored by those on the top of the information food chain. That says nothing about the rules of the game, but does say a lot about the people involved.
Can you recommend a book or two in order to learn about that culture? IMO we could use more of it in AI.
Relevant from Randall Munroe https://what-if.xkcd.com/29/
> What if I took a swim in a typical spent nuclear fuel pool? Would I need to dive to actually experience a fatal amount of radiation? How long could I stay safely at the surface?
> Assuming you’re a reasonably good swimmer, you could probably survive treading water anywhere from 10 to 40 hours. At that point, you would black out from fatigue and drown. This is also true for a pool without nuclear fuel in the bottom.
That blog post is about the spent fuel pool. The link is about the reactor cavity.
I have SOOO many questions, and this report answers SOOO few of them.
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?
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.
Realistically, there is little to do besides decontamination which I'm sure they're equipped to do on site.
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.
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?
Almost certainly a refueling outage, this video will give you a good image of it
https://www.youtube.com/watch?v=IoCfapqYy00
Palisades is not an operating reactor. It has been shut down since 2022. It's in the process of being recommissioned/restarted.
ooh, thank you for this!
It doesn't say worker, just "person." I could understand falling in with some freak accident where you trip. But they ingested the water?!
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?
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.
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?
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).
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/
What you "need to" do is often not decided by a rational risk assessment.
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.
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.
> They had 300 counts per minute which would e around 6200 mSv year
Are you sure about that? 6200 mSv is 6.2 Sv, which I understand to be near-universally deadly. That dosage would be profoundly incompatible with the news that the worker was being sent offsite to seek non-emergency medical attention.
Poking around, it looks like "counts per minute" have to get converted to a dosage using an instrument-specific formula. I CBA to go find that formula, but you're quite welcome to.
Rate matters. 6.2Sv in a single hour is fatal. 6.2Sv in a single year is probably less than average for a human from background radiation. The measurement units for ionizing radiation are very complicated and confusing. That's why people are told to not try to compute this stuff yourself. I have code that computes these units and conversions, its not simple. Here is a brief and simplified explanation of how you calculate this stuff.
There are 4 types of ionizing radiation: alpha, beta, gamma/x-rays and neutron flux. Each one has a different rate it is blocked by different materials (water, air, etc). Each one has a different risk to people. You have to compute counts per unit time emitted from a point source for each of the different types of radiation. Then you have to compute the amount of "arc" the person is in. Then you have counts being absorbed and you next multiply each count by a fixed factor depending on the type of radiation. This final number gives you total Greys per unit time, then you then have to divide by the mass of the person. Then you multiple that number by the total amount of time and that gives you total Greys absorbed. That's the number you use to assess risk to the person. For reference, this guy probably got less than 1 Grey. Someone getting radiation treatment for cancer might get 75 Greys.
So please stop trying to calculate this stuff yourself. I'm pretty sure you are doing it wrong. This guy will be fine.
PS Sieverts are a physical measure, Greys are a measure of biological "harm".
> PS Sieverts are a physical measure, Greys are a measure of biological "harm".
The US's NRC disagrees with you. From [0], they say this about the sievert and rem:
and have this to say about the gray: Grays seem to be "amount of radiation absorbed per kg". Looking further, the "Measuring Radiation" page at [1] directly contradicts your claim. Speaking about rems and Svs, it says: I'm definitely not an expert, but the NRC is pretty official, and their explanations sound pretty clear to me. Is what they're saying here incorrect?> 6.2Sv in a single year is probably less than average for a human from background radiation.
Are you sure about that? <https://xkcd.com/radiation/> claims 4 mSv per year as normal radiation dosage, and 50 mSv per year as maximum permitted annual dosage for "US radiation workers", whatever that means.
I think you're off by a factor of a thousand for the typical exposure level and off by a factor of a hundred for the exposure level where they stop letting you work near the radioactives for a year.
[0] <https://www.nrc.gov/reading-rm/basic-ref/glossary/full-text>
[1] <https://www.nrc.gov/about-nrc/radiation/health-effects/measu...>
no not sure. yeah I used the an average instrument specific rate. The point is a) everything emits, b) we have no idea on severity from the info, could be a little, could be a lot. Could also be short term (haircut) or longer term (ingested) exposures.
> yeah I used the an average instrument specific rate.
Would you provide a link to the source of this average instrument specific rate?
I'm interested in knowing which instruments designed to detect low-to-medium-level radiation sources on a human are configured so that five detections per second would equate to a "You're fucking dead; there's really no hope for you" dose.
(Did you ask an LLM to "convert counts per minute to mSv" and fail to sanity-check the confident-sounding result it gave you?)
> ...everything emits...
Given that the crust and sea and air of this planet are chock full of radioactives, and that every living thing on the planet builds itself out of that material, that goes without saying.
You need a device that can measure the different types of radiation. Then you have to do a bunch of calculations to estimate absorption. Only then can you calculate Greys which is the measurement that matters.
PS 300 CPM is nothing. There are places where people live where the natural background radiation is higher than that. Also, background radiation is mostly Gamma rays which is more dangerous than what comes off of fission products or nuclear fuel.
Hair can't hold that much water compared to any ingested amount. Whether contaminated or activated, internal irradiation from that much will be pretty bad.
"Complaining about residual radiation is for the weak." -- Lt. Worf probably
Klingon nuclear pools have springboards.
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.
I get the feeling that you don't know how complicated calculating radiation exposure is. There are plenty of interest in fear mongering against nuclear. Almost all the people talking about how much radiation 300 CPM is have absolutely no idea what they are talking about. Some confuse total measurement units for rates; others are using just the wrong units; still others are talking about levels that are 1000x or 1000000x higher than 300 CPM.
Or to put it another way, 300 CPM (which is a rate) is less than how much radiation you get when on a flight, or how much radiation you get at higher elevations. Even giving a simple explanation of how to calculate Greys (the actual measure you are looking for) takes up the better part of a page. Hell, your bones are radioactive. Yet there are plenty of people posting that somehow the risk to this guy is radioactivity. In reality, his biggest problem is probably going to be finding a new job.
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.
Huh why not. It's far less dangerous than, say, a train station or a viewpoint where everyone can just jump and die. Many reactors are open for kids and class trips where everyone can stare into a reactor
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.
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)
Not a good place to be a klutz!
Is he going to die no matter what or is this survivable?
Ultimately, yes; he will die no matter what.
As you get older this pedantry gets really tiring.
The good news is, you have less time to be annoyed by it
There is a deeper point here, not just pedantry. The point is that harm is a spectrum not a binary and one cannot meaningfully answer a question that assumes a binary.
Yes, there is a such a thing as a bad question after all.
Would it kill you? Well, ultimately yes..
Not necessarily. Could get hit by a car later the same day.
Personally, my belief in my own immortality only increases the older I get. Yes, Socrates died, but he clearly wasn't smart if he died. Me, on the other hand? I'm batting a thousand.
Unprovable.
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.
> They ingested some amount of cavity water
Isn't it much worse internally than hitting your outer skin?
I'm not an expert but it definitely doesn't sound like an immediate threat to his life.
Hopefully the worker is okay. I have to agree that the non-emergency classification seems odd. This should warrant a proper investigation and steps to avoid this in the future.
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.
Does the operator go to court for OH&S breaches?
I thought you could safely swim in that water so long as you stay a few meters clear of the rods? water being a good absorber of radiation and all. Is this just a precautionary reaction?
Scrolling up and down the list, just how onerous is this reporting regulation? It seems almost cartoonishly excessive, even for critical safety applications.
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.
Aaaand it’s this alarmist attitude which is why we don’t have abundant cheap nuclear energy.
Sea-drilling rigs (oil) have far more potential for environmental damage than modern nuclear plants
Yet they have no federal public register for when a worker falls overboard (an incident far more likely to result in death).
> Sea-drilling rigs (oil) have far more potential for environmental damage than modern nuclear plants
Key word: "modern". A key aspect of a modern nuclear plant, that supports its high level of safety, is the required incident reporting and followup.
The relevant issue is not really about a single worker being injured or dying. It's about detecting safety issues which could lead to a catastrophe far beyond what a sea oil drilling rig can, at least when it comes to human life and habitability of the surrounding area.
For example, after Chernobyl, much of Europe had to deal with contamination from cesium 137.
The entire planet's geological history shows when the nuclear age started, because humans are irresponsible in aggregate. (See also global warming.)
> Aaaand it’s this alarmist attitude ...
You're providing an object lesson in why humans can't really be trusted to operate systems like this over the long term.
> You're providing an object lesson in why humans can't really be trusted to operate systems like this over the long term.
Ironically so are you. The coal we burn puts far more radioactivity into the environment than nuclear plants do. Yet we make sure nuclear isn't viable and burn coal like crazy. We do this only because of the type of risk telescoping you are doing. If you do a rational risk assessment, you will see that even operating nuclear plants as shown in the Simpsons would have less risk than what we are doing now. There is a risk to doing nothing. You are missing that part in your assessment.
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.
The rest of the event reports are also very active. Reactor sites are fun places to work.
Your periodic reminder that coal is deadlier than nuclear.
https://cns.utexas.edu/news/research/coal-power-killed-half-...
More radiation released also which is hard to get your head around.
Not really hard: nuclear power generation uses radiation and radioactive material, but tries very hard not to release it. Coal power generation burns a substance that contains a small amount of radioactive material, and makes no effort not to release radiation.
It's not that surprising. We're burning a rock we dug out of the ground and turning it into a vapor. Rocks found underground contain some amount of natural radioactive material, for example granite/marble tend to be higher in radiation. If you burn that into a powder and put it into the atmosphere it'll spread around and expose the nearby area to very slightly radioactive pollution.
Interesting page overall. Didn't realize reactors get scrammed that often.
Does anyone have a sense for how significant of a dose of radiation this person got?
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.
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.
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
"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.
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.
They keep the water in an LWR pretty clean to avoid corrosion problems. Thing is the slightest almost of tritium in the water will light up a portal detector like a pinball machine on tilt.
Water is a pretty good radiation shield so probably not too much. Certainly not good for your health but probably not seriously threatening.
Pusat bantuan shopee
No more horseplay around the reactor!
Mandatory xkcd: https://what-if.xkcd.com/29/
Video format if anyone prefers it: https://youtu.be/EFRUL7vKdU8
I can't help but be reminded of relevant xkcd^{TM} https://what-if.xkcd.com/29/
If my childhood taught me anything, it’s that there’s about to be an awesome superhero.
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...
same thought here
and so hulk was born
Man in Michigan potentially exposed to radiation levels equivalent to undergoing 4 x-rays at the doctors office.
Meanwhile, in Texas, 1.5 people die every day working in Oil and Gas extraction.
A few people die every year installing or falling off of wind turbines.
But by all means, let's make this a news story instead and keep making nuclear sound scary. I’m sure the person who posted this to HN with this clickbait title has zero political beliefs.
Really puts it into perspective
Toxic Avenger remake.
Apparently it’s fine according to this xkcd: https://youtu.be/EFRUL7vKdU8
It's the reactor cavity in this case, not a nuclear waste storage pool.
How is that different from the accident point of view. They're both quite radioactive and both sit in deep pools of water.
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.
Relevant xkcd content: https://what-if.xkcd.com/29/
Is it relevant? It's writing about a pool for storing spent fuel, which is not a part of the actual reactor system.
> You may actually receive a lower dose of radiation treading water in a spent fuel pool than walking around on the street.
Wow
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?
They're totally fine.
I find it highly informative that the required PPE for working in that location is a life jacket so you float in case you fall in, rather than a tether and fall arrest harness so that it's not possible to fall in.
300 CPM is nothing, background levels might be 150.
Background is probably a bit lower depending on where you're at. My counter went through airport security luggage scans 'cause they wouldn't let me wear it through the metal detector. It beeps for a few seconds and then comes out about a days' dose of natural radiation higher. The count was higher than 300 CPM, but obviously only shortly. That poor bloke might stay at 300 (if ingested and he can't scrub it off) for a while but it's still not very discouraging long-term. Pilots have about that at cruising altitude.
Not bad, not terrible.
Did you mean “not great, not terrible” or was the change deliberate?
Dude about to have superpowers and go after the government
https://what-if.xkcd.com/29/
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.
relevant xkcd not: https://en.wikipedia.org/wiki/Andreev_Bay_nuclear_accident#A...
Obligatory XKCD: https://what-if.xkcd.com/29/
(Not exactly same but close)
Obligatory xkcd (ish)
https://what-if.xkcd.com/29/