the 1,200 mile length of the Atlantic seaboard of the United States. It 

 has been estimated that the average retention time for waters on this 

 shelf is about one year. Hence a conservative estimate of the "new" 

 water area available each month is l/lOth of the total area, or 4 x 10^0 

 m2. 



For unrestricted horizontal mixing, the value of n in equations 5 

 through 8 is 1.0. The value of the diffusion velocity is taken as 1.0cm/ 

 sec, as found by Joseph and Sender (1958). The pertinent equations for 

 the required computations then become 



M 

 (17) s (t) = 0.40 X 102 — 



(18) t =6.3 



ppc 



(19) 



M 



i ' ppc 



ppc 



2.3 X 10^6 ^ 3.6 X IQlS 

 \ ppc / 



Tables 11 and 12 present the pertinent computations. A compari- 

 son of the predicted activities in the primary coolant for the SAVANNAH, 

 given in Table 3, with permissible total activity per discharge, given in 

 Table 11, indicates that no undue risk to man would result from the 

 discharge of several thousand gallons of such effluent as a single re- 

 lease into the waters of the continental shelf seaward of a line 12 miles 

 from the coast. In fact, if each of the potential 300 nuclear-powered 

 ships were to make one such release per month into the waters of the 

 continental shelf off the east coast of the United States, the permissible 

 environmental levels would still not be exceeded. 



Table 4 shows that the total activity on the spent ion exchange 

 resins of the SAVANNAH is predicted to be about 400 curies after 50 

 days of operation. Since the ppc value for continental shelf waters, in 

 known fishing areas, for the mix of isotopes shown in Table 4, is about 

 2 x 10'° nc/ml, it is evident that not even one such discharge per month 

 into known fishing areas of the continental shelf would be suitable. 

 Even for those areas of the shelf which do not contribute materially to 

 fisheries, and where a weighted mean ppc value of 1 x lO'^ M.c/ml ap- 

 plies, the discharge of 400 curies at one time is not advisable. 



On the other hand. Table 6 shows that the total activity on the 

 spent ion exchange resins on the NAUTILUS amounts to about 12.5 cu- 

 ries. The ppc value for fishing areas on the continental shelf for the 

 isotope mix listed in Table 6 is about 6 x 10' ^ |ic/ml. Setting M equal 

 to 12.5 curies and s^pc equcd to 6 x 10' 9 ^c/ml in equation 19 gives a 

 maximum permissible number of releases per month of 36, or about 



42 



