occurred, but at a rate and in a manner which was below detectability 

 level, then wide dispersal of the gold-tagged sand would be noted. 

 Results of the experiments using the gold-tagged sand indicate the 

 xenonated sand did move. 



4. Gold Experiments 



On 4 October 1968, 24 packets containing about 14 cubic centi- 

 meters of sand tagged with gold 198-199 specific activity 47 microcuries 

 were placed as a simulated line injection 426 feet (130 meters) long 

 from -4 feet to -11 feet mean lower low water. The track of the vessel 

 during injection and conditions 2 hours after injection are shown in 

 Figure 16; and 4 hours after injection in Figure 17. Dispersal of the 

 tagged sand from one injection line 23 hours after emplacement is shown 

 in Figure 18. An hour after that survey, a second injection of gold- 

 tagged sand was made 600 feet upcoast. In this operation 36 packets of 

 gold-tagged sand (specific activity 22 microcuries) were placed as a 

 line 575 feet (175 meters) long from about +5 feet to about -6 feet mean 

 lower low water. The precise path the LARC XV described during injection 

 procedures is not known because of electronic problems. Due to wind and 

 longshore drift, the actual track was some distance downcoast (south) of 

 the planned line along Range 158 illustrated on Figure 19, which also 

 shows the dispersion of gold-tagged sand 2 and 26 hours after the second 

 and first gold injections, respectively. A subsequent survey on 5 

 October is illustrated in Figure 20. Results of the final full-scale 

 survey of this test 4 days later are shown in Figure 21. In total, 

 although not all surveys are illustrated here, 23 surveys of varying 

 duration and areal extent were conducted. The information from all plots 

 was used in drawing the maps in Figures 16 through 21. Longshore current, 

 sea, and swell during the experiment are summarized in Figures 22 and 23. 



Short cores of sediment were obtained along the injection range 

 (R-158) at elevations from -6 feet to +6 feet mean lower low water on 

 5, 7, 8 and 9 October. Cores were also obtained 50 feet north and south 

 of Range 158. No radioactivity was detected in the cores although surveys 

 showed tagged sand to be in the area. Lack of tagged particles in the 

 cores is judged to be due to the small diameter of the core and the rela- 

 tively few tagged grains which make the probability of coring tagged or 

 radioactive grains very small. 



As a result of burial, degradation of the higher energy photons 

 occurs with enhancement of the lower energy peaks, in this instance 80 

 kilo electron volts peak. Ratios of counts read in the two discriminate- 

 radiation counting channels are a measure of burial, i.e., the larger 

 the number the deeper the sand is buried. It is not yet possible to 

 give significance to burial depths indicated by the ratio, although the 

 qualitative significance is useful. Ratios of corrected count rate are 

 computed as follows: 



R 2 

 R D = k, - Ro 



24 



