Re: Heavy concrete info

[William V Lipton <liptonw@dteenergy.com>]

Quality control is crucial when using such materials, since the heavy components
tend to sink to the bottom.  A wall, for example, would have to be poured in such a
way that the lower layers cure enough to prevent migration of the heavy components,
but not so long that the concrete doesn't cure properly.

If the shield wall is for neutrons, it is also important to use materials with low
activation cross sections.  Trace elements can be a problem, so it is necessary to
have detailed specs for the concrete.

The opinions expressed are strictly mine.
It's not about dose, it's about trust.

Bill Lipton
liptonw@dteenergy.com


Dave Brown wrote:

> >I have designed a shielding enclosure specifying "heavy concrete", with a
> >density of ~3.2 g/cc rather than 2.35 for ordinary concrete. Our construction
> >people have no idea where to get this product. It seems that heavy concrete
> >can be mixed by adding magnetite or barytes to normal concrete (see Chilton
> >et al., "Principles of Radiation Shielding"). Are there suppliers that can
> >provide a mixture in the right proportions? I would appreciate any information
> >and pointers.
> >Thank you in advance
> >
> >Vashek Vylet
> Check out Reactor Experiments, they can probably help you or direct you to
> someone who can.....you could also try making it yourself.....
>
> http://www.nnc-usa.com/products_r.html
>
> Regards,
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Dave Brown, CHP
> National Institute of Standards and Technology
> 100 Bureau Drive, Stop 3543
> Bldg 235 Rm A136
> Gaithersburg, MD  20899-3543
>
> 301-975-5810 - office
> 301-921-9847 - fax
> david.brown@nist.gov
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> *The content of this message has not been endorsed by my employer*
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