For food organisms which obtain all or part of their food by in- 

 gestion of detritus which has settled on to the bottom (for example the 

 mullet, and some pelecypods and Crustacea), we should take account 

 of the concentration factors from bottom sediments to these organisms. 

 Unfortunately, there are no data on this. However, a conservative as- 

 sumption would seem to be that the concentration factor from bottom 

 sediments to marine food organisms is the same as from water to or- 

 gcinisms. Under this assumption, the maximum permissible concen- 

 trations in the bottom sediments, for estuarine and inshore waters 

 which support bottom-feeding organisms used as food for man, will be 

 the same as those tabulated for "environment" in Table 2. Since 

 certain of the radioisotopes with which we have to deal, especially those 

 which occur in particulate form in seawater, may be heavily concen- 

 trated in the bottom sediments, this may prove restrictive on the max- 

 imum permissible quantities which may be introduced into the super- 

 jacent waters. 



WASTES FROM NUCLEAR-POWERED SHIPS 



The Maritime Adrainistration's report (1959) gives data on the 

 expected quantities of various nuclides in the primary cooling water 

 and in the ion- exchanger s of N. S. SAVANNAH*. In Table 3 pertinent 

 data extracted from this report are tabulated for those isotopes in the 

 primary system which present the greatest potential hazard through 

 ingestion in marine food organisms. For the corrosion product nu- 

 clides, the report gives the concentration in the system. From this and 

 from the volume of the system (3.9 x 10^ ml) the total qucintity in the 

 primary coolant has been calciilated and tabulated. For the fission 

 products (assuming 1,530 grams of exposed fuel, 100 days operation, 

 and normal purification) the report gives the total quantity of each iso- 

 tope in the system. These also are tabulated, with the corresponding 

 calculated concentrations in the system. 



Since according to the Maritime Admiiiiistration's report there 

 will be 2 90 ft^ of discharge water due to expansion at each start-up, it 

 is possible to compute the resulting total amounts of each of the im- 

 portant isotopes which could be displaced per start-up. These values 

 are tabulated in Table 3. They may be used together with data from 

 Table 2 to compute minimum necessary dilution volumes. With dis- 

 charge in an environment (such as the open sea) where the accumula- 

 tion would be negligible, the minimum necessary dilution volume will 

 be obtained by dividing the partial permissible concentration for the 

 particular subdivision of the marine environment into the amount dis- 

 charged per start-up. For the discharge into a restricted segment of 

 the sea having only slow^ exchange with the open ocean waters, more 

 complex procedures, discussed later, raust be followed. 



♦Since completion of this report, subsequent re-evaluation of the probable character and 

 activity of the primary coolant and the ion exchange resins has been issued by the Oak 

 Ridge National Laboratory (1959). While the ORNL report includes somewhat different 

 values for the activity in these potential wastes, the general conclusions arrived at 

 here remain unchanged. 



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