24. 



results can be gotten by the simple addition of some small quantities 

 of a cheap chemical, eliminating the costs of steam and manpower 

 in evaporation. 



DR. T. P. KOHMAN: Does the ferrocyanide combine? 



DR. CHRISTY: The nickel ferrocyanide forms "floe" and pro- 

 motes sedimentation. 



DR. KOHMAN: Is the nickel salt added separately? 



DR. CHRISTY: The nickel and the salt are added separately. 



DR. H. C . THOMAS: Are you at liberty to say what the rela- 

 tive values of these wastes are? 



DR. CHRISTY: This is the sort' of thing I would rather not com- 

 ment on. 



DR. KOHMAN: Was this precipitation method the result of a 

 hundred different tests? 



DR. CHRISTY: No. The original compound developed in the 

 laboratory was copper ferrocyanide. Hanford optimized the technique, 

 and learned that nickel was a lot better than copper. More is being 

 learned. It has been found that calcium nitrate added to the mixture 

 gives more efficient clean-up of liquors. 



MR. WILLIAM LINDSEY: I think, while Hanford had a very 

 low water table, the waste was permitted to overflow and the soil held 

 all other fission products. 



This precipitation only retains some fission-products. Some 

 fission products flow over the tops of the tanks and into the soil. 

 This would be a serious matter except for the soil conditions at 

 Hanford which permitted it. As time went by, this process proved to 

 have quite a few limitations, one being the fact that we couldn't re- 

 cover the desired element. So another plant was built and is being 

 operated today, which we will call the S plant. This plant had a tank 

 farm and quite recently another large farm had to be added. (Mr. 

 Gorman mentioned tens of millions of dollars in tanks.) 



DR. CHRISTY: The thermal heat generated by the radioactive 

 decay of fission products is used to some degree successfully to 



