4 ms·
Here's numbers and a primary source [0]: "For perspective, the maximum potential radiation dose received by any ship's force personnel aboard the ship when it
by throwaway_yy2Di 13y ago
Here's numbers and a primary source [0]:
"For perspective, the maximum potential radiation dose received by any ship's force personnel aboard the ship when it passed through the area was less than the radiation exposure received from about one month of exposure to natural background radiation from sources such as rocks, soil, and the sun."
Meaning ~300 uSv, or three orders of magnitude short of acute radiation poisoning [1].
"Using sensitive instruments, precautionary measurements of three helicopter aircrews returning to USS Ronald Reagan after conducting disaster relief missions near Sendai identified low levels of radioactivity on 17 air crew members. The low level radioactivity was easily removed from affected personnel by washing with soap and water. They were subsequently surveyed, and no further contamination was detected."
(edit) By the way, [0] says the carrier was 100 miles from Fukushima at the time. Overlay that with the calculated I-131 dose map [2] (from [3]) (I-131 is the largest early dose component); it makes it really hard to believe any of these claims.
The paper [3] is relevant too: it shows off the ability to measure internal I-131 dose, long after the fact. And claims that people far closer to the disaster, with presumed far higher radiation exposures [2], are relatively safe.
[0] http://www.navy.mil/submit/display.asp?story_id=59065 http://www.navy.mil/submit/display.asp?story_id=59065
[1] http://xkcd.com/radiation/ http://xkcd.com/radiation/
[2] (figure only) http://www.nature.com/srep/2012/120712/srep00507/fig_tab/srep00507_F1.html http://www.nature.com/srep/2012/120712/srep00507/fig_tab/sre...
[3] (full paper) http://www.nature.com/srep/2012/120712/srep00507/full/srep00507.html http://www.nature.com/srep/2012/120712/srep00507/full/srep00...
- moocowduckquack 13y agoIf any of them have manage to ingest any of the snow, then they could be subject to long term internal exposure and depending on the type of source, it could be very difficult to scan for.
- toomuchtodo 13y agoOnce a radioactive source is in your body, even alpha radiation will kill you.
- jackweirdy 13y agoA note about your choice of the word "even" - Alpha radiation will kill you a lot more effectively than Gamma when it's inside you. This is for the same reason it's not damaging outside - Alpha radiation doesn't travel very far before being absorbed. When held close to skin, the majority is absorbed by the top layers of flesh and only a small amount will penetrate deeper. Conversely, when inside you, only a small amount will escape your body.
- sliverstorm 13y agoI'm still confused why the snow was radioactive. Snow = water. Did it form around radioactive particles?
- frankydp 13y agoThe low on the 13th was 33 around Fukushima. If the humidity was low enough it would not be impossible to have ground level or especially 250ft off the water snow. EDIT: misread your question. If the steam was radiated it "could" carry that downwind but the nature of decay would greatly reduce the possibility for anything at the size of snow to stay frozen at sea level.
- sliverstorm 13y agoRight, but to my understanding water can't become radioactive. It can contain radioactive things, but H2O doesn't turn radioactive. So I'm wondering why the snow was radioactive.
- moocowduckquack 13y agoIt may have nucleated around radioactive particles in the plume.
- awakeasleep 13y agoWe're all aware that seems feasible to a non-expert. Right now we're looking for someone who knows how to calculate possible radiation levels of snow.
- moocowduckquack 13y agohere ya go - "Tracking Radioactive Fallout from the Fukushima Dai-ichi Accident in Arctic Snow" http://adsabs.harvard.edu/abs/2011AGUFM.C33A0632O http://adsabs.harvard.edu/abs/2011AGUFM.C33A0632O
- 13y ago