(if successful, this material could have been used to seal activity on 

 dolomite type sands.) The experiment was discontinued after 2k hours 

 because of poor results. In the static leaching experiment, 26 percent 

 of the activity was lost to the aqueous environment . About 60 percent 

 of the activity was abraded away in the 2k hours. 



Study No . 7 - Monterey Sand - In this experiment the firing tem- 

 perature for the water-glass technique was reduced from 1030° to 500°C. 

 The seal at the lower temperature was inferior to that obtained at 

 1030°C. After 2k hours, 8 percent of the activity had leached away in 

 the static test and l6.k percent of the activity had been lost in the 

 abrasion experiment. 



Study Mo. 8 - Bear Creek Mo. 1, + 5 Sand - The sand was tagged with 

 Cr-51 radioactivity by the water-glass procedure. Approximately 1 percent 

 of the activity was leached from the tagged sand in the static test and 

 1.3 percent was in the aqueous phase due to abrasion. The experiment 

 extended over lk days. No sieving data were taken. 



Sieving Experiment with Bear Creek No. 1, + 5 Sand - An examination 

 of the size-distribution data obtained with Surf No. 2, MLLW sand in the 

 original form shows a considerable variation in the results (cf. first 

 row of data, Tables A-III and A-IV). Initially this was attributed to 

 poor sampling, probably caused by size fractionation of unknown origin. 

 For a test of this thesis, Bear Creek No. 1, + 5 sand was thoroughly mixed 

 for 15 minutes in a jar mill. Two 100-gram samples then were removed 

 and each was mechanically sieved for 15 minutes. The sieving results 

 are given in Table A- VI . These results should also be compared with the 

 results of the item designated "original" in Table A-V. Apparently mass- 

 size variations up to 5 absolute percent , which is larger than had been 

 anticipated, are to be expected. 



FUTURE PLANS 



Leaching and abrasion experiments for xenonated sand, supplied by 

 Oak Ridge National Laboratory, have been completed. The results obtained 

 will be incorporated in a subsequent report . A bibliography on sand- 

 tagging techniques has been completed in rough draft , and will be reported 

 shortly. 



CONCLUSION 



The NRDL procedure for sealing radioactivity to soils can be extended 

 to beach sands, provided carbonate minerals are absent or may be removed. 

 Over a 12-day period, about 1 percent of the radioactivity is removed by 

 static leaching processes, and from 1 percent to k percent of the activity 

 may be abraded away from the tagged sand. Losses of this small magnitude 

 are no cause for concern. It is inconceivable that they would either 

 jeopardize the results of the operation or constitute a health hazard. 

 These results apply to Ba-La-lUO and Cr-51 activities. Presumably any 

 radioactive element that is not vaporized at the firing temperature 

 (1900°F) can be used for tagging refractory sands. 



A-7 



