compacting rad waste

[Sharron A Daly <sdaly@csd4.csd.uwm.edu>]

In response to Jim Wickland's inquiry about compacting of rad waste, 
several years ago (5-7) we purchased a "Genie" waste compactor (the size 
that you would store in your garage, not your kitchen) in an attempt to 
reduce the volume of rad waste we were shipping off campus.  The 
paper/glass/plastic (solid waste) we placed in it came out of the 
compactor in a nice, relatively compact "cube" about 24" x 18" x 12".  If 
we place these cubes in a 55 gallon drum we had the problem of the "dead" 
or empty void space around the cube that reminded us of the square peg in 
the round whole problem.  Additionally, after a period of time the 
waste began to re-expand, popping the tie off the plastic bag it was 
contained in and except for the broken glass or plastic tubes, we 
eventually ended up with our original volume.  

We have found a very good use of the compactor, however, as we expanded 
our decay in storage program.  We now use the compactor every day to 
create "cubes" of dry P-32/I-125, etc. waste.  We receive the dry waste, 
insure that it is properly defaced within the bags that come from our 
research labs, remove the outside waste stickers and labels, and are able 
to compact several bags into a P-32 cube.  The cube is placed in a 
cardboard box (the size of the cube -- we purchase them as seconds from a 
vendor here in town), we label the box with the total activity and the 
estimated date of decay and are able to stack them in shelves in our 
waste vault.  We feel that by doing this we have probably tripled our DIS 
capacity.  The boxes serve well as a secondary containment method and we 
haven't experienced any "pop outs" or problems with the waste regaining 
its memory and expanding to it's original volume in the 18 months that we 
have been following this procedure.

For the long lived nuclides, however, we are still evaluating the 
purchase of a compactor from S&G Enterprises that will compact the waste 
and hold it in place with a plate that locks into the ring/groove of the 
55 gallon drum, keeping it under pressure.

Sharron Stenjem Daly
University of Wisconsin - Milwaukee
Radiation Safety Program
P.O. Box 413
Milwaukee, WI  53201
(414)229-4275
sdaly@csd4.csd.uwm.edu