The pertinent equations, using the symbols introduced in the last 

 section, then are: 



M 

 (14) s (t) = 3.2 X 102 — 



(15) t = 0.18 X 102 



ppc 



M 



ppc 



(16) N < 



2.2 X 1014 1.2 X 10l3 



ppc I s I 



\ ppc / 



Tables 9 and 10 present the pertinent computations. The proba- 

 bility is extremely small that there will be, on the average, more than 

 30 of the potential 300 nuclear-powered ships outbound through a single 

 such harbor approach per month. Since the w^eighted mean ppc, for 

 coastal waters, for the isotope mix in the primary coolant is approxi- 

 mately 10"^, it is evident from a comparison of Table 10 with Tables 3 

 and 5 that this segment of the continental shelf can safely receive the 

 discharge of warm-up expansion volumes which may have been stored 

 in tanks aboard ship, due to restrictions on the release of this waste 

 into the inshore environment. 



Since it is considered undesirable to average over a period longer 

 than one month, the maximum permissible amount of activity in a single 

 discharge, even if less than one such discharge were to be made into 

 the subject area per month, is about 5 curies. An inspection of Tables 

 4 and 6 then indicates that this segment of the continental shelf would 

 be unsuitable as a receiver of spent ion exchange resins. 



EVALUATION OF THE OUTER CONTINENTAL SHELF (ZONES 3a 

 AND 3b) 



For the region of the shelf from 12 miles seaward to the 200 

 fathom line, diffusion on a pertinent scale would be unrestricted by 

 horizontal boundaries. Within this area a mixing layer depth of 40 

 meters may be assumed. Though there are significant areas of this 

 shelf region which are not fished commercially, migratory fish traverse 

 the whole of the continental shelf, and it is not possible to assume that 

 any segment is biologically uninn.portant, though some parts of the shelf 

 contribute significantly less to the total fisheries than others. 



The continental shelf off the east coast of the United States is uti- 

 lized here as the subject area for our computations of the safe rate of 

 discharge of radioactive wastes from nuclear-powered ships into this 

 type of marine environment. The region of this shelf from 12 miles 

 seaward to the 200 fathom line averages about 100 miles in width over 



40 



