Re: Help! (Basement radiation surveys)

[Dimiter Popoff <tgi@cit.bg>]

Jay,



the only practical measurement I can think of for the case you describe

is by using some portable Ge detector based system. NaI spectgroscopy 

might be sufficient if you know what you are looking for - say, 137Cs

or 60Co or both, but the resolution is much less than what you need

to qualitatively assess an unknown source mixture.



Dimiter



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Dimiter Popoff                                    ++359/2/9923340

Transgalactic Instruments, Gourko Str. 25 b, 1000 Sofia, Bulgaria

http://tgi.cit.bg       tgi@cit.bg     dimiter.popoff@firemail.de

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> We are working on surveying a basement area and part of the surveys 

> include gross gamma counting w/ NaI detectors.  We've done fairly 

> extensive measurements with handheld probes and smears to detect fixed 

> alpha, beta or removable alpha, beta, gamma, but wanted to provide a 

> little extra assurance that we didn't miss something.  Our problem lies in 

> building materials and background in certain areas.  Part of the basement 

> is open top (no ceiling), part is concrete slab ceiling.  Secondly, two 

> areas of the basement are similar to dead end hallways and this is where 

> the concrete ceilings are also.  Naturally, the gamma counts are going to 

> increase as we enter the 'hallway' areas due to increased NORM.  However, 

> I'm looking for a somewhat simple way to quantify this increase and 

> reassure someone who is looking at my data that it is NOT contamination. 

> Does anyone know of any modeling I can apply to this situation?  Anyone 

> have similar experiences?  We have looked all over the site for similar 

> building configurations and have come up empty handed at this time.  If 

> you have any advice, please reply directly to me, or you may reply to the 

> list if you feel there may be some other poor souls out there like me:)

>  

> Thanks,

> Jay

  

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