39. 



feet above the ground water table. The volume of waste that goes 

 into this crib is determined by laboratory tests, and the tests are 

 extrapolated, witn adequate safety factors, to an actual field instal- 

 lation. There is an elaborate system of wells around the crib to 

 detect the presence of radioactivity away from the crib installation. 



DR. JAMES GILLULY: What about under it? 



DR. LIEBERMAN: Well, they can tell what is getting in the 

 ground water . 



DR. GILLULY: I wouldn't expect anything to move laterally 

 300 feet above the water table. I would expect the changes to take 

 place under the crib. 



DR. LIEBERMAN: The monitor wells might be on the order 

 of 30 or 50 feet away from the crib, and activity has been detected 

 in these wells. When field installation is made, only the volume of 

 soil in the 30 by 30-foot column under the crib down to the water table 

 is considered; the operators feel they are getting the benefit of a big- 

 ger volume as far as exchange capacity is concerned. It is known that 

 an element like ruthenium will go right through the column, but it is 

 also known that ruthenium has a half-life of one year and that the travel 

 time of the water from the bottom of the crib to the Columbia River 

 is of the order of magnitude of tens of years or hundreds of years. 

 The rate of flow is the subject of debate among the ground water geol- 

 ogists, but in any case, they are sure that before this water which 

 might be contaminated with ruthenium gets to a place where somebody 

 can use it, it will have decayed to the point where it is no longer harm- 

 ful. 



I am sure that the people who are involved in this work at Hanford 

 would be the first ones to say that we can't take the results that we are 

 getting here and apply them to any other place. Obviously, it is a 

 question of environment, every location on its own merits. 



DR. H. C. THOMAS: It is true, then, that no spot other than 

 Hanford has actually been investigated from this point of view? 



DR. LIEBERMAN: That isn't quite true. This afternoon Dr. 

 Struj-aiess and Mr. Morton will summarize the investigative work being 

 done at Oak Ridge in connection with surface pits that Floyd Culler 

 mentioned earlier. But on a routine production basis, shall I say, at 



