30. 



trations that can be achieved at large distances from the leaching source 

 will be greater than for free diffusion. 



K the behavior noted immediately above is taken as the basis for 

 choosing between containers that will immediately release the wastes 

 to the environment and ones that will permit a slow release, the choice 

 should be in favor of the latter. In the specific example cited, the 



leaching container reduces the initial peak concentration by a factor of 



4 

 nearly 10 , compared to immediate release, yet the peak concentration 



occurring at 10 km from such a source is less than 10 times greater 

 than from the immediate release container. Furthermore, containment 

 is desirable as it allows natural radioactive decay to reduce the quantity 

 of activity that will ultimately be presented to the environment. 



Information concerning the rate of corrosion of steel containers, 

 comparable to those now used in the preparation of wastes for sea dis- 

 posal, and the leaching rate of radioactive substances from concrete, 

 is presented in Appendix X. Corrosion rates of steel in sea water 

 suggest that with the presently used kind and thickness of container 

 material, containment of the concrete-waste mixture will last for 

 approximately 10 years. The only leaching rate studies cited were 

 carried on for relatively short periods of time. While not sufficient to 

 provide an indication of long-term leaching behavior, they do suggest 

 that liberation to the environment from concrete mixtures will be 



