Sandblasting Grit

["Mays, Mark" <maysm@wrigem.wpafb.af.mil>]

I am looking for information related to concentrations of naturally 
occurring radionuclides (specifically Th and U) found in sandblasting grit. 
 I have been unable to find reference in NCRP reports.

A government contractor possessed a license for thorium for purposes of 
mag-thor panels for aircraft.  The license was terminated in the 60's.  The 
NRC recently performed a survey of the government owned property and 
confirmed grit on site contained Th and U.  The NRC stated in their report 
"request that you (the Air Force) present evidence that indicates that the 
thorium contained in the grit is not previously licensed material or submit 
your proposal regarding the proper transfer or disposal of the sandblasting 
grit ".   Purchase orders to obtain manufacturer of the grit and perform 
analysis is not available and disposal as radioactive waste is in question.

The concentrations in the grit are 15 pCi/gm Th and 21 pCi/gm U.  The NRC is 
applying the release criteria found in NRC's Branch Technical Position, 
Disposal or Onsite Storage of Thorium or Uranium Wastes From Past Operations 
(Federal Register, Volume 46, Number 205, October 1981, pp 52061-52063). 
 The release criteria is 10 pCi/gm.

Any information regarding this topic will be beneficial.

==================================
Mark L. Mays
WPAFB Radiation Safety Officer
88 ABW/EMB     Bldg 30089
5490 Pearson Rd
Wright-Patterson AFB, OH 45433-5332

Voice:  (513) 257-2010  DSN 787-2010
Fax:      (513)476-1534   DSN 986-1534
e-mail:  maysm@wrigem.wpafb.af.mil