133 Xe radiation was detected. These injections and the associated surveys 

 were hampered "by very large rocks. Therefore the third, and last, injec- 

 tion, which was placed on the ocean floor by scuba divers, was made in an 

 area that was relatively free of rocks. This injection was successful, 

 and surveys were made in the area for three consecutive days. 



A radar navigation system was used in this survey. Navigational fixes were 

 taken at 2-min intervals and the data were entered in a time log, as were 

 the starting and stopping times of the analyzer. Recorded count levels 

 were corrected for background and decay and then plotted. 



Observations 



The Surf operation established that 1 ^fe-tagged sand can be traced for 

 several days over relatively long distances. Charts of isoactivity con- 

 tours (Fig. C- 5) showed that the tagged sand from the last injection had been 

 dispersed over an area approximately 600 by 1200 ft when surveillance ended 

 (after 3 days). From all, indications the batch could have been traced for 

 a much longer period of time, perhaps up to ten days after release. 



The detector system worked well. Tracking performance and towing stability 

 were good; however, several changes in equipment and in operational proced- 

 ures were indicated, such as better correlation of data. Analysis of the 

 data showed areas that should have been covered more extensively and areas 

 that required less coverage. Also, slight variations in the time log and 

 in the recording of the starting and stopping times of the analyzer ' made it 

 very difficult to analyze the data. Although some protection was afforded 

 by a metal .shelter available at the test site, it was evident that better 

 protection would be required for the electronic instruments. 



Alterations Indicated by Test 



Following the Surf operation a system was designed and built to integrate 

 and record location, time, and radiation data (see Fig. C-6). A real-time 

 readout of typewritten and punched paper-tape records allowing instantan- 

 eous evaluation of results, as well as a more sophisticated analysis at a 

 later time, was provided. 



An instrument shelter was built (Fig. C-7)which incorporates enclosed motor 

 generators and a complete forced-air handling system to keep the instru- 

 ments dry. The instruments and the shelter are completely self-supporting. 



Since it was recognized that the Point Conception area would be a very dif- 

 ficult area to survey because of extensive rock outcropping and severe surf 

 conditions, backup equipment was built. A complete spare detector assembly 

 was fabricated. The electronic equipment has been fabricated with enough 

 flexibility to permit the interchanging of components. This feature ensures 

 the accumulation of radiation data. For example, since each detector is an 

 independent unit, one or all four can be operated at any given time. Two 

 data-recording systems exist, and if the automatic data-correlation system 

 should fail, data can be accumulated manu all y by using the multichannel 

 analyzer. 



C- 14 



