os a oe ~ _ - + ae A NER FL #, "WRNTeme ee “Le CHAPTER 5 CONTROL GROUP ore To provide for the radiological safety of all personnel entering radiologically contaminated areas, a Rad-Safe Control Group was organized. This organization consisted primarily of survey groups and escort monitors at Eniwetok, Kwajalein, and Ujelang atolis. One member was also added to the Scientific Group aboard the Scripps Institute vessel, Horizon. §.1 FUNCTIONS The Control Group station was established in the forward ready room of the USS Rendova . while afloat and in the Rad-Safe office in Building 57 when ashore. Current radiological-situa- tion maps were maintained at this station for the information of project leaders and escort monitors, re Doo, oe PETeT ge n none ate .: = eae op CO eRe eae arenasTE OS EM BOS ET. OSoie, REE, TE eg Tere tot This station provided current information to the Rad-Safe Information Center (RIC) pertaining to the location of all monitors engaged in operations. It maintained an operationa table of details on all missions into contaminated areas scheduled for each day, including name of monitor, destination, general type of migsion, transportation, and time of departure and arrival. This station constituted the clearance point for ail working parties prior to entry into contaminated areas. Monitors assigned to the various scientific parties were familiarized with the problems that might be expected to arise in each operation. When necessary, survey teams monitored all islands and posted radiation-level signs in specified areas so that work teams could plan their activities without exceeding the allowable exposure. Areas with levels of radioactivity higher than 100 mr/hr were outlined and marked by warning signs. Resurveys were made at frequent intervals to reestablish the 100 mr/hr line. Entries beyond the 100 mr/hr line required escort by a monitor. The Control Group Officer met initially with the Scientific Deputy of TG 132.1 daily to plan operations for the following day. 6.1.1 Results The operating procedure (Appendix C) was adequate for the operation, although the communications broke down at several critical times. In two instances contact was lost with the initial helicopter survey because of last-minute frequency changes for which the helicopter had ‘ no crystal and becaure of the excessive use of the main communication channel by other agencles. This deficiency was corrected by installing a separate Rad-Safe channel. The initial helicopter survey, which departed 10 min after Mike detonation, was aborted prior to accomplishment of the misaion because it had become cuntaminated by radioactive fall-out in the upper lagoon. This indicated the fallacy of early initial surveys. 25