Re: in need of advice

[John Andrews <andrewsjp@chartertn.net>]

Think of the surface as if it were a boat hull.  If there is a hole in 

the hull the boat fills with water.  Same with the gasses from radium 

isotopes.  If you don't coverall the surfaces with a substantial 

coating, then the problem will persist, although it may be reduced.  

Epoxy coatings seem to work on floors.  Thoron has a shorter half life 

than radon, so it may be reduced more than radon will be with the same 

coating.  Based on your numbers, there may be more thorium present than 

just a surface coating that could be removed. Is it really a problem?  

Can the exposure be tolerated over 40 hours?  You might also consider 

using local electrostatic filtration or hepa filtration to control the 

levels of the particulates.  Just some thoughts.



John Andrews

Knoxville, Tennessee



Jay Beckel wrote:



> We have an area that has varying amounts of fixed thorium 

> contamination, few hundred to few thousand dpm/100cm2.  As you would 

> guess, the radon (thoron) levels are quite high in some places.  The 

> areas consist of utility tunnels underground with little or no 

> ventilation.  Ventilation seems to be the obvious choice, but would 

> some sort of sealer work at all? Scabbling up the concrete that the Th 

> is embedded in is not really an option due to confined spaces and 

> other obstacles.  If anyone has any advice or knows someone who might 

> be able to help out, let us know!

>

>  

>

> Thanks,

> Jay

>

>  

>

>  

>





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