[ RadSafe ] Skyshine measurements

[Olsson Mattias :MSO]

Hi all,

One BWR plant is to do a power uprate to 120% of the original effect.
During the testing period there will be dose rate measurements in
selected places around  the plant to observe changes in skyshine from
the steam lines in the turbine building. In the documentation it says
that the measurements should be done during weather with "low clouds".
This is supposedly because low clouds will give you a conservative
measurement. There is no source given and I don't have the necessary
software to make a model of it. So what I want to ask is if any of you
could say if it is obviously conservative to measure skyshine with low
clouds (compared to high clouds or sunny weather) and if there is some
standard practice for skyshine measurements around nuclear plants. Being
a humble chemist, it's not obvious to me, although it seems reasonable
that clouds could cause more scattering.

All the best,

Mattias Olsson
Forsmark, Sweden