RE: Barite (barium sulfate) - rad shield qualities?

["Jacobus, John (OD/ORS)" <jacobusj@ors.od.nih.gov>]

Shane,

I am not sure why you would want to build a fallout shelter, since

evacuation is the preferred method..  (For some reason, I picture someone

riding around in a pickup truck carrying bags of barium sulfate to set up a

fallout shelter in a moments notice.)  



Barium sulfate is the primary ingredient used in plaster and in barite

concrete, which was used in the construction of older diagnostic radiology

facilities.  I good source for comparing the attenuation ability of

different materials is

http://physics.nist.gov/PhysRefData/XrayMassCoef/cover.html  There are

graphic representations of mass attenuation data that may be helpful.  Since

the elemental composition of ordinary concrete is 30% silicon and 4% calcium

by weight (I do not know of what your dirt is composed), barium sulfate

which is 58% barium by weight would make a much better shielding material

for photons.  Of course, the size of the bags may be a factor in the size of

the shelter you build since the density of barium sulfate is three times the

density of dirt.



-- John 

John Jacobus, MS

Certified Health Physicist 

3050 Traymore Lane

Bowie, MD  20715-2024



E-mail:  jenday1@email.msn.com (H)      



-----Original Message-----

From: Shane Connor [mailto:shanec@gvtc.com]

Sent: Monday, December 17, 2001 12:03 PM

To: radsafe@list.vanderbilt.edu

Subject: Barite (barium sulfate) - rad shield qualities?





Radsafers,

We've had some inquiries from visitors to our sites

that some here might help me to correctly respond to.



Another member here was also good enough to point

me to an interesting study on the radiation shielding

qualities of barite. This brief 2-page report that tested

and compared it to lead and lead glass is here...



http://www.irpa.net/irpa10/cdrom/01213.pdf



My question is: Does the quality of barite as a gamma

radiation shielding material extend beyond its simply

being a high density material?



More specifically, if 100 lb sacks of it were used in an

expedient fallout shelter, and the likely isotopes to be

encountered in fallout from nuke bombs, terrorist dirty

nuke bombs or nuke plant catastrophes, is barite any

better a shielding material than simply piling on more

100 lb sacks of dirt? (Ignoring cost differences here.)

. . .

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