one per day. In non-fishing areas of the continental shelf, where the 

 environmental ppc value for the isotope mix on the ion exchange resins 

 is about 3 x 10"^ ij,c/ml, the permissible number of releases of ion ex- 

 change resins having the activity reported for the NAUTILUS is com- 

 puted to be about ZO per day. 



According to the report "Radioactive Waste Disposal from U. S. 

 Naval Nuclear-Powered Ships", the ion exchange resins in the NAUTILUS 

 require replacement about once each six months. Thus, if each of the 

 potential 300 nuclear-powered ships were to discharge their spent ion 

 exchange resins twice each year, in a random spatial distribution over 

 the continental shelf of the eastern United States, the environmental 

 limits for this area would not be exceeded, provided that the total activ- 

 ity on the spent ion exchange resins for each ship would not exceed 50 

 curies . 



EVALUATION OF THE OPEN SEA (ZONES 4a AND 4b) 



For the purposes of this report, the open sea is considered to 

 consist of those regions of the oceans v/hich are more than 12 miles 

 from any land and which have depths gieater than 200 fathoms. The 

 open sea undoubtedly has greater capacity to safely receive radioactive 

 wastes than any of the marine environments previously considered. 

 Since the waters of the outer continental shelf are suitable receivers of 

 the low level liquid effluent from nuclear-powered ships, it is evident 

 that no restriction need be placed on the discharge of low level liquid 

 effluent from nuclear-powered ships into the open sea. This statement 

 is valid so long as the activities in the liquid effluent are similar to 

 those observed on the NAUTILUS and predicted for the SAVANNAH. 



The major source of potential wastes for marine disposal on nu- 

 clear-powered ships are the spent ion exchange resins. According to 

 the report "Radioactive Waste Disposal from U. S. Naval Nuclear-Pow- 

 ered Ships", these resins sink in sea water and also rapidly give up the 

 attached active isotopes to the sea water. It is a basic requirement for 

 the application of the findings of this study that in all cases these resins 

 must sink when released into the sea. 



In the evaluation of the dispersed, of an inoculant in the open sea, 

 using the equations developed by Joseph and Sender, a layer depth of 

 100 meters is assumed. Since no boundaries exist to restrict horizon- 

 tal diffusion, at least on the scale of concern here, n inequations 5 

 through 8 would be equal to unity. The value of P, the diffusion velocity, 

 is taken as 1 cm/sec. 



In determining the total area A^ to be used in evaluating the cri- 

 teria expressed by equation 1, it is conservatively assumed that all 

 300 potential nuclear-powered ships operate in the New York-London 

 route. The area of this route is estimated at 6 x 10^ km^ (6000 km x 

 100 km). The length of the significant time period T is, as in the eval- 

 uations for the inshore and continental shelf areas, taken as 1 month, 

 and ti/2 is taken as 15 days. 



44 



