Five grams (5-00 g) of xenonated sand were weighed into each vial. 

 Next the vial was filled completely with distilled water. The amount of 

 water added was measured with a burette. Then the caps were secured, and 

 for insurance of a seal, the vials were inverted until they were radio- 

 assayed. The vials used in the abrasion experiments were placed in a 

 Parr agitation apparatus in an inverted position. They were agitated in 

 this position until they were assayed. A calibration standard was pre- 

 pared at the same time as the experiments. The standard consisted of 

 6.O78T grams of the dry xenonated sand in a 15 by 125-millimeter test 

 tube. The tube was not sealed. The standard was radioassayed each time 

 aliquots of supernate from the vials were assayed. A semilogarithmic 

 plot of the count rate of the standard vs. the time showed that, from 28 

 to ^36 hours, it decayed with a half life of 5-29 days. The good agreement 

 with the published Xe-133 half life (5-27 days) indicates that no loss of 

 Xe-133 occurred by escape into the atmosphere during this time. Zero time 

 for all experiments was set at the time the vials were filled with water. 



At various times after the experiment began, supernates from a static 

 experimental vial and from an agitated vial were radioassayed for the 

 presence of outgassed Xe-133. A ^-milliliter aliquot was removed from 

 the vial and radioassayed as quickly as possible. (Rate of loss of Xe-133 

 from an aliquot was determined in a collateral experiment.) The assay was 

 made with a Sodium Iodide (Nal) (Tl-activated) crystal scintillation well 

 counter. The vials were discarded after the assay. The time selected 

 for a radioassay did not follow a set pattern. The time was determined 

 more by the results of the previous assay and by the desire to extract as 

 much information as possible from the results than by any other con- 

 sideration. Altogether the time lapse for all the experiments extended 

 over about two Xe-133 half lives (i.e., 10 days ) . 



The xenonated sand was provided by Mr. F. N. Case of Oak Ridge 

 National Laboratory (ORNL) . Carbonates had been removed at ORNL prior 

 to xenonation. Because of a misunderstanding, the sand was not received 

 until the middle of May 1967 • Thus only one batch of sand was available 

 for experimental purposes. 



RESULTS AND DISCUSSION 



The pertinent data for both sets of the outgassing experiments are 

 shown in Table A-VII. The data include the time lapse from zero to assay 

 time, the total activity of the sand standard, the activity (calculated 

 from the specific activity of the standard and the activity lost to the 

 water) of the sand in the vial after exposure, the volume of water re- 

 quired to fill the vial, the total activity (calculated) of Xe-133 in 

 the aqueous phase, and the percent of outgassed Xe-133. The calculated 

 activities (all corrected for background) were for the times indicated 

 in the first column. 



After 28 hours the amount of Xe-133 outgassed from the sand in the 

 static experiment corresponded to 3.5 percent of the amount remaining in 

 the sand. After 219.5 hours the figure had increased to 5-5 percent. 



A-13 



