55 



AssiiminiT that the rate of atmosplieric testing is not appreciably 

 greater than it was over the past 5 years, tliis vahie will remain the 

 same or even decrease. It should be noted here, only to place this total 

 pollution content in perspective, that the natural radioactivity in the 

 oceans, principally potassium-40 is about 1,000 times greater than 

 that which fell in from the weapons tests. 



Nuclear fission reactors have numerous applications, such as: Elec- 

 tric power, desalination, vehicle propulsion, research, and production 

 of special materials. The major growth, Avorldwide, will almost cer- 

 tainly be in the power production category. 



The reactor process is essentially a controlled nuclear chain reaction, 

 hence all of the same potential pollutants are produced; fission prod- 

 ucts from the splitting of the fuel atoms and neutron activation prod- 

 ucts from reactions with materials in the environs of the core, where 

 the chain reaction takes place. 



By design, the fission products are meant to remain in the core of 

 the reactor, within the encapsulated fuel elements. There have, how- 

 ever, been cases of leaks, as well as accidents allowing releases to the 

 environment. 



Because of the requirement for extensive cooling of the reactor core, 

 they are for the most part built near rivers. Water from the river is 

 pumped through the reactor, and returned to the river. 



Most often, it is in this operation, that the activation products are 

 formed from impurities in the coolant water, and these are commonly 

 found enterincf the sea. 



' The potential for environmental pollution is much greater in the 

 reprocessing of the nuclear fuels. Here, the spent fuels are purified of 

 (he fission products in order to reclaim and reuse the fuel. The highly 

 radioactive, long-lived fission products recovered in this process plus 

 certain components of the fuel constitute the nuclear waste which must 

 be managed to prevent the possibility of leaks to the environment. 



This management must be maintained literally for hundreds and 

 perhaps thousands of years. Hence, the high-level wastes, too, consti- 

 tute a pollution threat. T^ow-level wastes from reprocessing plants have 

 been, and to some degree, continue to be disposed of in the oceans. 



Table 4 lists the approximate concentrations of the long lived radio- 

 active pollutants in seawater and sediments, near shore, in the neigh- 

 borhood of operating reactors, resulting from controlled disposal of 

 wastes. 



TABLE 4.— CONCENTRATIONS OF SOME WASTE POLLUTANTS IN SEAWATER AND SEDIMENT i 



Seawater Sediments 



Hs .'.. 10 -100 



Fe«.... 0.01-10 :. 



Sf»« 1 -100 



Csi3? 1 -100 100-10.000 



PuM» 100-100,000 



> The units are pCI per liter for the seawater and pCi per kilogram for the sediments. 



Table 5 shows the lange of concentrations Avhich have been ob- 

 served in marine organisms, attributable to controlled waste disposal 

 at sea. These data also were obtained near shore. 



26-282 O - 74 - 5 



