[ RadSafe ] Airborne radioactivity

[Harold Careway]

Franz, 
I'm guessing I may know what is going on here but can't really help.  Given
a line carrying a radioactive gas, if that line breaks under water the gases
can be released to the water and depending upon flow rate, gas content,
temperature of the gas and water, and water depth; the resultant bubbles can
be scrubbed in the water resulting in various levels of contamination in the
air above the water as well as in the water. Up to the point of entrainment
in the water, the process is strictly physical and non-chemical.  Once the
material is in the water, chemical variations compound the analysis. The
solution is non-trivial (you need elliptic integrals) and though the NRC has
done significant work in this area, the only really accurate and valid work
I've ever seen was done by GE Nuclear and is strictly proprietary.   

To find what is available you can start with NUREG/CR-5901, "A Simplified
Model of Aerosol Scrubbing by a Water Pool Overlying Core Debris Interacting
With Concrete", then go onto Google and look for "pool scrubbing" and
"DECON".

Frankly, trying to do a realistic calculation or model is extremely really,
really hard to do.  I know of no rules and thumb and would be interested if
anyone else does.

Hal Careway
San Jose, CA
GE Retired.

-----Original Message-----
>From Franz Schönhofer
Sent: Monday, April 09, 2007 4:38 PM

Dear Health Physicist,

This is the first of two messages today, which request from RADSAFErs some
information without giving even the slightest details. As a Health Physicist
you should know, that there are thousands of different radionuclides, which
behave differently, coming in different chemical forms, have different
solubility etc. etc. Do you want to know the radon level to be
expected...... bla, bla, bla. 

Not being a native speaker I regard "air line" being rather in the context
of "DELTA", "Austrian Airlines", "Lufthansa", "Iberia" etc. 

I hope you can explain, what you really want.

Franz



Franz Schoenhofer, PhD
MinRat i.R.
Habicherg. 31/7
A-1160 Wien/Vienna
AUSTRIA


>From Earley, Jack N

Does anyone have any calculations or guidelines for determining the
resulting airborne radioactivity levels from an air line breaking under
water, relative to the air flow rate (or from performing an air sparge
in radioactive water)? 
 
 
 
Jack Earley
Health Physicist
509.372.9532