JAIF reports radiation readings as of 09:00, Mar. 30th (20:00:00 Tuesday March 29 ET)
- 1.05 mSv/h (1050 μSv/h) at the south side of the office building
- 169 μSv/h at the Main gate
- 78 μSv/h at the West gate
Previous readings at the West Gate
- 120.0 μSv/h at 21:30, Mar. 28 (08:30 am Monday March 28 ET)
- 122.8 μSv/h at 15:30, Mar. 28 (02:30 am Monday March 28 ET)
- 132.5 μSv/h at the West gate at 16:00, Mar. 27 (03:00 am Sunday March 27 ET)
I was wondering if you had perused this document.
http://www.meti.go.jp/press/20110319002/20110319002-2.pdf
On page 2 at 17:00 hours it gives a reading of 5055. micro/s/h. Does this translate in to 5 milli/s/h? It looks to be in ten min. increments so while not a stable number isn't it high?
I think alpha radiation can be blocked by a variety of things and maybe beta by some. How much will the workers be affected by radation if exposed to say 2.5 milli/s/h over a periods of several days?
Do Beta burns appear immediately or is their a period of latency? I thought I read that some of the burns take almost 20 days to appear?
Thanks for you time.
Posted by: Trina Bashore | March 30, 2011 at 02:10 PM
Very interesting document. It looks like you're right. The reading is 5055 μSv/h, or 5.055 mSv/hr. That is very high. In Canada the recommended maximum annual exposure for the public is 1 mSv/yr, and for nuclear workers 50 mSv/yr.
The types of radiation are alpha (helium nuclei), beta (electrons and positrons), and gamma (short wavelength electromagnetic). A piece of paper can stop alpha particles, but gamma requires lead.
Radiation sickness symptoms are seen when one is exposed to approximately 1 Sv or higher over a short period of time, and symptoms can appear in a matter of hours. Long term exposure to elevated radiation levels increases the risk of cancer.
Posted by: Geoff | March 30, 2011 at 08:21 PM