5 ms·

I don’t know how to read that chart. How do we know the levels increased? What did they used to be? who operates that site? What are safe levels?

by Rd6n6 5y ago

CommieBobDole 5y ago
Each of the detectors has a detail graph of radiation over time if you click on it - a lot of them show a many-fold increase in radiation in the last few hours. Particularly concerning are some near the reactor building itself that went to a fairly high reading very quickly (65500 nSv/h in one case, which is likely offscale high) and then stopped reporting at 21:50 local time (it's currently 03:30). 65500 nSv/h is definitely not 'you're going to die right now' radiation levels, but it's definitely getting into the territory of stuff you don't want stand around in for too long. If I've done the math right, I think that's about three times the allowed annual exposure for radiation workers every hour. Edit: I think I didn't do the math right and am off by 1000x. 65500 nSv/h is like three chest x-rays an hour. Which is still not good, but would take quite a bit longer to get really dangerous.
- freemint 5y ago
  Note that 65500 = round(typemax(UInt16)/100)*100 and no higher value exists on the map it might actually be worse how much we can't tell though.
  - hirenj 5y ago
    What a grim coincidence if this type of saturation error pops up again in relation to Chernobyl.
    - dTal 5y ago
      Is it a coincidence? Or are dosimeters commonly calibrated for a maximum reading of "not great, not terrible" for best sensitivity in the range they're likely to be needed for? This maximum reading is 50 times less than the famous "3.6 Roentgens".
  - dTal 5y ago
    Nice use of Julia to communicate with humans. However, since you've chosen to communicate through code, strictly speaking it ought to be '==' :p
    - freemint 5y ago
      Yes, I write Julia but I didn't use Julia on purpose. It just feels natural syntax, which I guess is an compliment to Julia.
- Rd6n6 5y ago
  Very helpful, thanks!
- deleted 5y ago
  [deleted]
Thetawaves 5y ago
Click on one of the sensors to see the trend.
Pinegulf 5y ago
Safe when it comes to radiation is tricky question. Since potential damage is random you might get cancer from first gamma-ray or you might survive nuclear fallout. (www.en.wikipedia.org/wiki/Daigo_Fukury%C5%AB_Maru) However, in practice yearly 'safe' limit for civilian population is 20 mSv (ref: https://www.stuklex.fi/en/ohje/ST7-2 https://www.stuklex.fi/en/ohje/ST7-2) The map is nSv /h. Lets take dot with 2000 nSv/h. In order to obtain yearly limit you need to hang around for 10 hours. Whereas 65000 area would be around ~20 minutes. Please bear in mind that this is gross simplification.
- rkwasny 5y ago
  You are off by 1000x: 2000 nSv/h * 10 hours = 20 μSv (microsieverts) = 0.02 mSv (millisieverts)

I don’t know how to read that chart. How do we know the levels increased? What did they used to be? who operates that site? What are safe levels?

by Rd6n6 5y ago

I don’t know how to read that chart. How do we know the levels increased? What did they used to be? who operates that site? What are safe levels?

CommieBobDole 5y ago

Each of the detectors has a detail graph of radiation over time if you click on it - a lot of them show a many-fold increase in radiation in the last few hours. Particularly concerning are some near the reactor building itself that went to a fairly high reading very quickly (65500 nSv/h in one case, which is likely offscale high) and then stopped reporting at 21:50 local time (it's currently 03:30). 65500 nSv/h is definitely not 'you're going to die right now' radiation levels, but it's definitely getting into the territory of stuff you don't want stand around in for too long. If I've done the math right, I think that's about three times the allowed annual exposure for radiation workers every hour. Edit: I think I didn't do the math right and am off by 1000x. 65500 nSv/h is like three chest x-rays an hour. Which is still not good, but would take quite a bit longer to get really dangerous.

freemint 5y ago
Note that 65500 = round(typemax(UInt16)/100)*100 and no higher value exists on the map it might actually be worse how much we can't tell though.
- hirenj 5y ago
  What a grim coincidence if this type of saturation error pops up again in relation to Chernobyl.
  - dTal 5y ago
    Is it a coincidence? Or are dosimeters commonly calibrated for a maximum reading of "not great, not terrible" for best sensitivity in the range they're likely to be needed for? This maximum reading is 50 times less than the famous "3.6 Roentgens".
- dTal 5y ago
  Nice use of Julia to communicate with humans. However, since you've chosen to communicate through code, strictly speaking it ought to be '==' :p
  - freemint 5y ago
    Yes, I write Julia but I didn't use Julia on purpose. It just feels natural syntax, which I guess is an compliment to Julia.
Rd6n6 5y ago
Very helpful, thanks!
deleted 5y ago
[deleted]

Thetawaves 5y ago

Click on one of the sensors to see the trend.

Pinegulf 5y ago

Safe when it comes to radiation is tricky question. Since potential damage is random you might get cancer from first gamma-ray or you might survive nuclear fallout. (www.en.wikipedia.org/wiki/Daigo_Fukury%C5%AB_Maru) However, in practice yearly 'safe' limit for civilian population is 20 mSv (ref: https://www.stuklex.fi/en/ohje/ST7-2 https://www.stuklex.fi/en/ohje/ST7-2) The map is nSv /h. Lets take dot with 2000 nSv/h. In order to obtain yearly limit you need to hang around for 10 hours. Whereas 65000 area would be around ~20 minutes. Please bear in mind that this is gross simplification.

rkwasny 5y ago
You are off by 1000x: 2000 nSv/h * 10 hours = 20 μSv (microsieverts) = 0.02 mSv (millisieverts)