= 2 
The solvent extraction processes may be grouped into three general 
categories for the purpose of describing the characteristics of the wastes 
which they produce. 
A salted process uses a solvent which favors the formation of organic 
soluble nitrate like ether. It is necessary to add an inorganic complex 
of uranium and plutonium. The salting agent, such as aluminum nitrate or 
copper nitrate, is contained in the waste and is the principal chemical to 
be dealt with in the disposal problem. The nitric acid salted system uses 
another solvent, tributyl phosphate, diluted with a hydrocarbon diluent. 
This system has the advantage of requiring no salting agent other than 
nitric acid so that the wastes contain few inactive salts since the nitric 
acid can be removed by evaporation. The enriched we? diluent salted process 
is quite similar to the salted natural uranium-plutonium process, but in 
this the salting agent may be the alloying element in the fuel assembly. . The 
diluent follows fission products into the highly radioactive first cycle waste 
stream. 
Physical Properties of Wastes: The physical properties of the wastes 
resulting from the processes described are listed in Table 5. The solid 
salted process waste may be concentrated by a factor of 3 by evaporation, but 
this is the limit for the residue is then solidly set-up. The volume of solids — 
in some of these wastes after evaporation may be reduced by only a factor of 2 
because of bulking. 
Wastes may be stored as they come from the extraction tower, but some 
are neutralized, usually with sodium hydroxide, before they are stored. A 
large volume increase upon neutralization in the enriched uo? process occurs 
due to the presence of amphoteric salts which require a large volume of 
neutralizing agent. The neutralized volume is approximately 4 times the un- 
neutralized volume. 
DECLASSIFIED 
