6. 



or reactors producing liquid waste should be undertaken without delay. 

 The question should not be phrased: "How can we dispose of waste at 

 X site?" but should be: "Can or cannot waste be disposed of at X 

 site?" The possibility of the negative answer should always be con- 

 sidered. 



SPECIFIC RECOMMENDATIONS ON DISPOSAL 



1. Storage in tanks is at present the safest and possibly the 

 most economical method of containing waste. 



2. Disposal in salt is the most promising method for the near 

 future. Research should be pushed immediately on the structural 

 problem of stability vs. size of cavities at a given depth; on the 

 thermal problem - getting rid of the heat or keeping it down to ac- 

 ceptable levels - and on the economics of such disposal. (Appendix F 

 by Heroy) 



3. Next most promising seems to be stabilization of the waste 

 in a slag or ceramic material forming a relatively insoluble product. 

 This could be placed in dry mines, surface sheds or large cavities 

 in salt. 



4. Disposal of waste in porous beds inter stratified with im- 

 permeable beds in a synclinal structure is a possibility for the more 

 distant future. This is of particular interest for disposal of the 

 large volumes of waste to be expected in the future. Very difficult 

 and complex problems have to be solved before it will become feasi- 

 ble . The reaction of the waste with connate waters or constituents 

 of the rocks soluble in the waste solution will have to be studied. 



The composition of the rocks and the connate waters are both variable 

 as will be the composition of the waste solutions so that an almost in- 

 finite variety of circumstances result. In general acid aluminous 

 waste would almost certainly tend to form precipitates which would 

 clog pore spaces. The problem would have to be solved first for a 

 given bed at a given site for a given waste solution at a given dilution. 



137 90 



5. The removal of Cs and Sr from the waste would make 



disposal somewhat easier for the waste free of these isotopes but 

 does not change qualitatively the recommendations made in the report. 



6. In the complex relations between (a) storage time of waste 

 for cooling, (b) transportation cost in shielded carriers and (c) dis- 

 tance to disposal site, the last of these factors must be considered 



