were launched from the Boxer at sea. In these cases the survey party first a proceeded to Enyu to clear the island and the ship anchorage for re-entry % ? and then proceeded with the remainder of the survey. In general, two survey crews carried out the survey simultaneously, one covering the southern half of the atoll, the other covering the northern half. 3.1.4—Monitors for recovery or construction parties were provided as required. The demand was quite small. As at Eniwetok, projects provided their own monitors, 4 3.1.5-—The radiochemistry trailer was located in the TG 7.1 Adminis- 7 z trative Compound. The Laboratory Section handled 318 water, soil, and food 4 samples. Water samples were taken from the water supplies of the various % ships and from the Enyu swimming area. The swimming beach was closed q j for 1 day following the Fir event due to radioactive contamination. Fi 3.2 ef si Shots and Survey Results Very little interference with preparations for firing the various devices 38 was caused by excessive contamination. On two occasions placement of a 4 shot barge was delayed for 24 hr due to the radiation levels. Some delay in recovering diagnostic film from the photo tower on Chieerete was experienced; @ Surface decontamination by filling and grading of the western end of Eninman ; was required to reduce contamination resulting from the Hickory event. The 3 road on Romurikku was scraped and graded to aid recoveries following the ie Maple event. Table 3.1 gives a summary of the various events at Bikini Atoll. H+4 hr survey results are indexed by figure number in Table 3.1. ae ™iH : oe Not shown by the H+4 hr survey results is the fact that radiation read-%: ings on the west end of Eninman were quite dependent on tides. Several reve a covery operations had to be scheduled with high tide in order to take advan~3 5 tage of the lowest radiation levels, This ‘particularly affected a number of | i” the stations that were very close to the high tide line. It is to be noted thal ‘high readings were never uniformly recorded at any particular tide stage. This was of particular concern before the Hickory event since considerable »am effort by construction crews to build a sea wall on the west end of the a = was required. +s Contaminated water resulting from the barge shots fired in the northe! part of the atoll usually moved out fairly rapidly. Generally speaking, re-* entry into the water zero site could be made within 24 hr. As mentioned previously, positioning of subsequent shot barges was delayed on two al1 for 24 hr due to radiation levels, but this was in part a result of surface 3 contamination that prohibited the engineering survey crews from oceupyins ~ 84 -