[ RadSafe ] Video of Meter - Up to 10,20 µSv in Ichinoseki, Iwate Prefecture 163km from Fukushima Dai-ichi
Rees, Brian G
brees at lanl.gov
Mon May 23 12:22:40 CDT 2016
OK, 0.18 or so uSv/hr is a slightly high background, but certainly not a level to get too concerned about. Since I live at 6800' (2,070 m) I may see that depending on surrounding soil/rock formations. So it appears that the selection of uSv/hr is appropriate. Since the dose rate light is blinking on the instrument I doubt if the reading is in some unit of count rate.
The meter is moved a meter or so horizontally , and a reading of 0.51 uSv/hr is observed. The 0.51 uSv/hr reading is substantially higher than most backgrounds, and interesting, but again, certainly not a level to get concerned about.
The time constant of the instrument is long, and the reading does not appear to be a result of electronic interference from something like a radar, or other transmitter.
The meter is then moved closer to the ground - it looks to me to be moved about 1-2' (30-60 cm) closer- and a reading of 10.2 uSv/hr is observed. The instrument behavior and increase in reading appears to me to be a result of distance, and if you assume it's being held a few cm from the ground, seems to ROUGHLY follow a 1/r2 relationship. It may be a hot particle, or similar point-like source. This is not a dangerous level, and if the source is at or near ground level, not an external radiation hazard, or a great hazard if ingested (along with however much dirt you'd also be ingesting).
So, it's not a dangerous situation, it's interesting, and since hot particles containing fission products may be found from time to time as a result of the Fukushima reactor accident, shouldn't be terribly alarming.
From: radsafe-bounces at health.phys.iit.edu [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Roger Helbig
Sent: Monday, May 23, 2016 6:52 AM
Subject: [ RadSafe ] Video of Meter - Up to 10,20 µSv in Ichinoseki, Iwate Prefecture 163km from Fukushima Dai-ichi
Is this meter or its reader perhaps being mislead due to lack of experience or other cause?
You are currently subscribed to the RadSafe mailing list
Before posting a message to RadSafe be sure to have read and understood the RadSafe rules. These can be found at: http://health.phys.iit.edu/radsaferules.html
For information on how to subscribe or unsubscribe and other settings visit: http://health.phys.iit.edu
More information about the RadSafe