KIT -Reply

[FRAMEP@ORAU.GOV]

Johnny:

The collection here (to which you are a generous donor) has one of
these kits.

They date from the 50s' 60s. and contained radioactive material in
various amounts. They were used in high schools for the most part.

They were placed on a sheet of film/paper for a short period (perhaps a
couple of days). The film was developed and the image used to rank the
blocks according to activity.

I can tell you what is in mine and the chances are good you have the
same materials: The thorium series in equilibrium. What the equilibrium
was when these kits were produced I won't guess at. It also has U-238,
U-234, U-235, Th-234, Pa-234m. 

No Ra-226 etc. which means they have processed uranium.

Best wishes

Paul Frame
Professional Training Programs
ORISE
framep@orau.gov