Re: THORIUM AND URYNAL COMPOUNDS

[David Scherer <scherer@uiuc.edu>]

At 03:16 PM 5/21/96 -0500, Myung Chul Jo wrote:

>Uranyl nitrate and thorium nitrates are considered oxidizers, refer to 40
>CFR 261.21. and 49 CFR 172, and radioactive. However, 40 CFR 268.9
>have "Special rules regarding wastes that exhibit a characteristic". U, Th
>nitrates exhibit the characteristic of ignitability. The waste analysis and 
>recordkeeping requirements are stated in 40 CFR 268.7. 
>
>Here is what I did, (1) file waste analysis and treatment plan to regional
>EPA  (2) Our treatment plan was to deactivate the ignitability of U, Th
>nitrate powder by solidifying in concrete (3) After approval from the EPA,
>U, Th nitrates are mixed with concrete and solidified. (4) The solidified
>nitrates no longer exhibit the characteristic of ignitability. (5)
>Therefore the solidified nitrates are treated as low level
>radioactive waste.  
>
It is my understanding that the Resource Conservation Recovery Act
specifically excludes materials regulated under the Atomic Energy Act.
Since U and Th are defined as source material, they are AEA-regulated and
exempt from RCRA.  Mixed waste comes into the picture only when the
AEA-regulated materials are comingled with RCRA-regulated materials.  For
example Pb-210 would not be mixed waste, because it is byproduct material.
If it were mixed with stable Pb in a form that was a characteristic waste,
the combination would be mixed waste.  (At least, that was the guidance I
received at an EPA mixed waste workshop in Chicago during February, 1992.)
It would appear that U and Th wastes would follow similar considerations.

Any comments from EPA employees or other experts?

Dave Scherer
scherer@uiuc.edu