36. 



return, somewhat decayed, for eventual disposal. We are going to 

 have to put those some place and have somebody concerned about 

 them for an extended period of time. 



This focuses attention on the processes described earlier which 

 may be characterized as "pulling the teeth" of these wastes. This 

 refers to the selective and essentially quantitative removal of the 

 Cesium 137 and the Strontium 90 isotopes. If and when the "teeth" 

 can be removed, practically and economically, from the mixtures of 

 fission products, two different problems are created. The first has 

 been mentioned. The effective half-life of the mixed products obtained 

 from fissioned uranium has been estimated to be of the order of hun- 

 dreds of years. If strontium and cesium are removed, the effective 

 half-life of the remaining mixture is reduced by perhaps a factor of 

 ten; thus the remaining material might have an effective half-life fig- 

 ured only in tens of years but indiscriminate return to the environment 

 of material with such radioactivity is, nevertheless, unthinkable. 



The possibility of fixing these radioactive materials on an earth 

 carrier is being studied. At Brookhaven the radioactive ions have 

 been fixed on montmorillonite clay primarily by ion exchange; then, 

 by heating the clay, the exchange reaction is made irreversible. 

 This "hot" clay could be stored in special locations that would prevent 

 the radioactive material re-entering the human environment. 



A.E.C. employees who labor daily with this problem are faced 

 with the constant question, "When can we stop building tanks? or, 

 When can we do something with these wastes other than putting them 

 in tanks ? " The chemical technologists , the physical chemists, the 

 biologists, and many other disciplines have a part to plan in finding 

 the solutions. What are the facts in the earth sciences field that bears 

 on the possibility of putting these wastes in the ground? Then, just 

 how do we go about deciding whether it is possible to put this stuff in 

 the ground and at which locations? Then, just how do we go about put- 

 ting these wastes in the ground? Specifically, the questions to be an- 

 swered are as follows: 



a. What are the problems, environmental and geological, asso- 

 ciated with putting this material in the ground? 



b. Assuming that underground disposal is feasible, where can 

 we do this, and under what conditions? 



