Re: Getting away from Fiestaware

["Michael P. Grissom" <mikeg@SLAC.Stanford.EDU>]

Actually, the activity was probably in the tile's glazing!

Thorated sands used in the process were often the source.  I
have seen older laboratories where tiles generated such
high backgrounds (>1,000 CPM--normal background 100 CPM--with 
a shielded pancake GM) that wipe surveys (with the wipes read 
outside of the room) were the only way to determine 
contamination status!

An observation,

MikeG.

At 02:39 PM 6/7/96 -0500, you wrote:
>Peter, I don't know the isotopes, so I would make the same assumptions you
>did, but I have often heard that various types of ceramics have elevated
>levels of radioactivity in them.  I remember a case where I had to perform a
>survey at a worker's residence, and found roughly twice bkg on the tiled
>surfaces in the bathrooms.  (I was using a standard pancake gm frisker)
>Since there were no special colorings in the tile, and it was a relatively
>new home, I would assume that the activity was in the clay - probably
>radium, thorium, etc.
>
>Keith Welch
>Thomas Jefferson National Accelerator Facility
>Newport News VA
>welch@cebaf.gov

-----------------------
Michael P. Grissom
Special Assistant, SLAC
mikeg@slac.stanford.edu
Phone:  (415) 926-2346
Fax:    (415) 926-3030