are all lower than the computed maxiraum perraissible activity, even 

 for ten discharges per day. It therefore appears that discharges of 

 liquid effluent in the quantities and activities similar to the warm-up 

 volume of primary coolant from the NAUTILUS may be made into the 

 majority of inshore areas w^ithout introducing undue risk to man. How^- 

 ever, it should be pointed out that the "typical" harbor used in this eval- 

 uation, while representing an area of rather poor flushing character- 

 istics, does not represent the w^orst inshore area from this standpoint. 



It is therefore necessary that specific evaluation be made of any 

 harbor or inshore waterway which is to be utilized as a base or as a 

 major port of call for nuclear-powered ships. Such an evaluation 

 should include a study of the routes by which activity introduced into 

 the particular harbor or waterway may return to man; of the principal 

 marine products harvested from the area; of the concentration factors 

 to these food products both from the water and from the bottom sedi- 

 ments; and of the physical processes of movement, mixing and exchange 

 of the waters of the particular marine locale. 



A similar comparison of the computed permissible activity of a 

 single discharge, -with either the predicted activity for the spent ion ex- 

 change resins from the SAVANNAH, or the observed activity on the re- 

 sins from the NAUTILUS, contained in Tables 4 and 6, leads to the def- 

 inite conclusion that spent ion exchange resins should not be discharged 

 in harbors or other restricted coastal waterways. 



EVALUATION OF THE COASTAL AREA (ZONE Z) 



For this coastal area from 2 to 12 miles offshore, equations 1 

 through 8 in the previous sections may be utilized, setting 0^^ = 180° 

 ajid n = 2, to take into account the possible limits placed on diffusion 

 by the coastline. A conservative mixed layer depth of 10 meters is 

 taken for this computation. The diffusion velocity _P^ is assumed to be 

 equal to 1.0 cm/ sec, which is the value found by Joseph and Sender 

 (1958) for a number of phenomena of varying scale in the open sea. 



Releases of wastes from nuclear-powered ships in this regime 

 will probably occur priraarily in areas off major ports, with rather 

 definite approach routes. The size of the representative area, _A, to be 

 utilized in equation 1 is obtained by considering a 10 mile wide slice 

 extending seaward from two miles offshore to 12 miles offshore. A 

 current parallel to the coastline of velocity less than one mile per day 

 would provide for essentially complete replacement of the volume under 

 consideration during the representative time period of one month. 

 The value of A, is then 3.8 x 10^ m^, and t2/2 equals 15 days. 



39 



