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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 cl

300 CPM in hair after decontamination is a massive red flag. If this is from systemic circulation, could be GBq-level total body activity. The non-emergency classification is bureaucratic nonsense. This is an internal contamination event with unknown but potentially severe consequences.

ramchip 1y ago
From: https://www.vice.com/en/article/a-nuclear-plant-worker-fell-into-a-reactor-pool-and-somehow-survived/ 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.
- deleted 1y ago
  [deleted]
arthurcolle 1y ago
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
- orwin 1y ago
  External contamination is not comparable to internal, at all. Bq is a terrible unit to understand radioactive danger. Doses are usually detected in Grey, then converted into Sievert because Grey didn't take into account the difference between Alpha radiation and the others. And even then, when someone is truly contaminated, we calculate effective dose per organ. The poor guy who fell in the pool probably didn't take any Alpha ray, wasn't taking all the radiation on a specific place, and while in my country we would calculate the dose he took before sending him back to work, he would probably work again in the same nuclear sector (this isn't the case for anyone, I know someone who dive to get the radioactive/explosive/poisonous trash we put in the water in the 50s until the 90s, he now cannot work on any radioactive trash.)
malfist 1y ago
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?
- __MatrixMan__ 1y ago
  Quantify? What kind of number would satisfy your request?
- arthurcolle 1y ago
  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 https://en.wikipedia.org/wiki/Ronald_Coll%C3%A9?wprov=sfti1
  - malfist 1y ago
    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?
    - arthurcolle 1y ago
      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 https://github.com/arthurcolle/Ronald-Colle-Papers I love how punchy you are! And the astronomy photos. Take care :)
      - fekxpurrrt 1y ago
        [flagged]
LeoPanthera 1y ago
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/ https://what-if.xkcd.com/29/
- arthurcolle 1y ago
  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.
  - LeoPanthera 1y ago
    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.
  - beeflet 1y ago
    >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.
hunterpayne 1y ago
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.
- kragen 1y ago
  GBq is also a measure of rate; it's a billion decays per second.
Someone 1y ago
> 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.
raggi 1y ago
There is no circulation in hair, hair is dead, and it is produced slowly. Nothing about your commentary passes basic scrutiny.
beowulfey 1y ago
Unless I'm misinterpreting what you mean, I believe if it was reflected in the hair in the immediate aftermath, it wouldn't reflect internal circulation because hair does not grow that fast. It would have been from exposure to the pool rather than any amount ingested.
harrall 1y ago
300 CPM on its own is both meaningless and not high. CPM is a raw stat from the sensor. There’s many different designs of dosimeters and they all read differently so you have to ask “what brand and model did you use?” You then apply a function to the data to normalize it into a real unit. But CPM is the cool thing that makes the click-click-click sound. (The absolute rate of clicks also is not useful.)

ramchip 1y ago

From: https://www.vice.com/en/article/a-nuclear-plant-worker-fell-into-a-reactor-pool-and-somehow-survived/ 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.

deleted 1y ago
[deleted]

arthurcolle 1y ago

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

orwin 1y ago
External contamination is not comparable to internal, at all. Bq is a terrible unit to understand radioactive danger. Doses are usually detected in Grey, then converted into Sievert because Grey didn't take into account the difference between Alpha radiation and the others. And even then, when someone is truly contaminated, we calculate effective dose per organ. The poor guy who fell in the pool probably didn't take any Alpha ray, wasn't taking all the radiation on a specific place, and while in my country we would calculate the dose he took before sending him back to work, he would probably work again in the same nuclear sector (this isn't the case for anyone, I know someone who dive to get the radioactive/explosive/poisonous trash we put in the water in the 50s until the 90s, he now cannot work on any radioactive trash.)

malfist 1y ago

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?

__MatrixMan__ 1y ago
Quantify? What kind of number would satisfy your request?
arthurcolle 1y ago
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 https://en.wikipedia.org/wiki/Ronald_Coll%C3%A9?wprov=sfti1
- malfist 1y ago
  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?
  - arthurcolle 1y ago
    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 https://github.com/arthurcolle/Ronald-Colle-Papers I love how punchy you are! And the astronomy photos. Take care :)
    - fekxpurrrt 1y ago
      [flagged]

LeoPanthera 1y ago

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

arthurcolle 1y ago
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.
- LeoPanthera 1y ago
  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.
- beeflet 1y ago
  >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.

hunterpayne 1y ago

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.

kragen 1y ago
GBq is also a measure of rate; it's a billion decays per second.

Someone 1y ago

> 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.

raggi 1y ago

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

beowulfey 1y ago

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

harrall 1y ago

300 CPM on its own is both meaningless and not high. CPM is a raw stat from the sensor. There’s many different designs of dosimeters and they all read differently so you have to ask “what brand and model did you use?” You then apply a function to the data to normalize it into a real unit. But CPM is the cool thing that makes the click-click-click sound. (The absolute rate of clicks also is not useful.)