uniformity of rates of attack for specimens exposed under 

 conditions of continuous immersion. . . . The spread is 

 between 0.001 and 0.0077 ipy (inches penetration per year) 

 with an average of 0.0043, . . .For a rough estimate in 

 the absence of data applying to a particular locality or 

 condition of exposure, it would be reasonable to use a 

 figure of about 0. 005 ipy, or about 25 mdd (milligrams 

 per square decimeter per day), for the expected average 

 rate of corrosion of steel or iron continuously immersed 

 in sea water under natural conditions. ..." 



With this average corrosion rate, i.e. 0.005 ipy, one can calcu- 

 late roughly that the drum would lose its integrity in about 9.5 or 10 

 years (0.0478 -r- 0.005)* However, this calculation may not be too 

 important because not all packages have welded and sealed tops and 

 bottoms. In some cases, the drums may have open tops and the 

 concrete would be exposed at the time it is immersed. 

 Leaching of Radioactivity from Concrete 



In an experiment performed by Vitro Corporation of America it 

 was determined that about 4. 8% of the total MFP activity (added as 

 the liquid component in a mortar mixture) was leached out in a 

 period of 15 days. 



In similar experiments performed by another AEC contractor, 

 small mortar cylinders (approximately 1 inch diameter x 2 inches 

 high) spiked with small amounts of MFP activity were leached in 2 

 liters of tap water. These experiments indicated that about 2% of 

 the activity was leached out in about 40 days. About 5% of the calcium 



