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are all lower than the computed maximum permissible 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 without 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 worst 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 2) For this coastal area from 2 to 12 miles offshore, equations 1 through 8 in the previous sections may be utilized, setting 9n = 180° and 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 primarily 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 jA is then 3.8 x 108 m2, and t1//2e1uals 15 days. 39
