[ RadSafe ] Skyshine measurements

[Olsson Mattias :MSO]

Sounds like sound reasoning to me. If someone asked me to organize this measurement and comparison I would probably suggest to first do all measurements when the weather is clear, to get the relative impact from the reactor effect on the skyshine dose rate under comparable conditions. "Low clouds" sounds a bit vague to me. After that, one or a few measurements could be repeated at any reactor effect with "low clouds", and if the factor (value low clouds)/(value nice weather) > 1, all values are corrected with this factor to include the possible conservatism due to clouds.

(In this case conservatism is mostly interesting because there are offices that are somewhat affected by skyshine, and there is a maximum allowed dose rate level for office spaces.)

Mattias

-----Ursprungligt meddelande-----
Från: radsafe-bounces at health.phys.iit.edu [mailto:radsafe-bounces at health.phys.iit.edu] För JOHN.RICH at sargentlundy.com
Skickat: den 6 mars 2013 16:46
Till: The International Radiation Protection (Health Physics) Mailing List
Ämne: Re: [ RadSafe ] Skyshine measurements

As a first approximation it doesn't seem like it should be a large effect. 
 The N-16 gammas scatter off electrons so the density of electrons is what matters.  Clouds have small water droplets which have a higher electron density than air.  But, is there enough water in the clouds to make a real difference? (I don't have a clue on this one.  Perhaps a meteorologist could calculate the difference in electron density to see if it makes 
enough difference to matter).   Also it depends on the height of the cloud 
cover.  If the clouds are at 1000 meters it might affect the skyshine.  If 
the clouds are at 10,000 meters, it probably won't.   Calculating the 
effect of various cloud covers would be a good master's thesis

Anybody else have any ideas. 

 --jmr