16 



SUMMARY 



A number of formulas have been given in the preceding discussion in the 

 attempt to shed some li^t on the question of maximum conceivable concentrations 

 of radioactivity which may result in the vicinity of a low level radioactive disposal 

 area on the sea bed in relatively shallow water. The distribution at distances well 

 outside the disposal area is reasonably illustrated by Table I which is based upon 

 Eq. (27) for a water depth of 30 meters, a very small diffusivity (1 cm^/sec) 

 and a relatively weak current (5 n. mi/day), and applies to the case of Cs ^^' at 

 an estimated supply rate of 100 curies per year. Concentrations for other isotopes 

 can be estimated by proportion (based upon their rate of supply relative to 100 

 curies/yr) . 



The maximum possible activity concentration in the water within the disposal 

 area is simply the concentration within any individual package ( C . ) , considering 

 that the package is suddenly destroyed. The peak concentration as a function of 

 time at the source, in this event, is shown in Fig. 3. The maximum relative 

 concentration as a function of distance based upon a single source is shown in Fig. 4. 

 This is pertinent only in consideration of the distribution of concentration within the 

 disposal area. 



An analysis of the rate of leaching of the packages indicates that an accumulation 

 of the order of 10 to 20 years is required in order to establish an overall leaching 

 rate which equals the rate of accumulation.. This indicates that the natural decay, 

 which is ignored in the preceding considerations will lead to concentration much less 

 than the example computations given in Table I, if it is considered that leaching is 

 the governing factor in regard to the supply of radioactivity to the water. 



