uaa. acncowwasen: meres tary se SEC Us ll owen whe ree ee cena wate et see Tw 8 { waa ae Pit sagt be exposed to radiation. ver of such exposures for Operaiics areenhouse is, -ty 1400 ¢mr.—HS Tho maximum that would be acquired had been estimated as 1,190 mr. The as usual, the film badge. Film oadges, with films for Japtan indicated a mean of 1,040 mr records indicating to whom each badge wasisand a range of &25 to 1,600 mr, where the sued, are stored at Los Alamos for reference in the event of any claim against the governmaximum had been estimated as 1,310 mr. The maximum value for Japtan was estimated from ment which might arise in the future. For personnel living on islands or ships at survey meter readings which were about 10 per Eniwetok Atoll, the external radiation exposures indicated in Figs. 2.7 to 2.13 must be increased by the contribution of the fall-out, particularly after Dog and Item shots, bearing in mind the fact that personne) doing routine duties, sleeping, and eating indoors would receive only one third to one half of the dosage measured out in the open. It would be extremely difficult to estimate accurately the total exposures received by these personne! since film badges were not, in general, worn on homeships or islands. cent greater than those on Parry. No comparable data are available from Eniwetok Island, but survey meter readings made early in the fall-out showed intensities of about two thirds of those on Parry. 2.7.2 Following the fall-out from Dog shot, cumulative dose data were obtained on Parry using photographic film badges and pocket ionization chambers. The readings were taken near the In all cases, exposure records of personnel radiological safety building after a survey indicated that this was a representative area. Readings were discontinued on 14 May 1951 when the decay had reduced the daily dose to 20 mr. Figure 2.8 shows the cumulative doses due to the fall-out from Dog shot and the subsequent lighter fall-out from Easy shot. The figures given represent doses which would have been received out-of-doors. Doses actually received were less than the figures given, depending upon the daily activities of the individuals. working in radioactive areas were scrutinized after each day’s operation, and persons who approached or exceeded established tolerance levels were so informed and cautioned not to enter radioactive areas for certain lengths of time. In general, cooperation of test personnel with radiological safety instructions was excellent. 2.7.1 Cumulative Radiation Dose Due to Dog Day Fall-out Dog Shot In the early phasesof the fall-out after Dog shot, radiation levels inside buildings were from one third to one half those found outside. To determine maximum possible integrated radiation doses, film badges were exposed outside the rear of the radiological safety building. These badges were replaced at 24-hr intervals and were supplemented by pocket dosimeters when decay had reducedthe levels of activity. The build-up of the Dog day fall-out is shown in Fig. 2.1. Cumulative dose data are shown in 2.7.3 External Radiation Doses to 27 April 1951 An analysis of all radiation exposures as shown by photographic film badges was made as of 27 April 1951. The exposure data presented represent only that obtained in various missions Fig. 2.7. Assuming decay according to t™'** and no loss from leaching, the maximum doses expected can be calculated as 2,210 mr to D+30 days and 2,705 mr to D+60 days. Film badges were given to a group of monitors in TU 3.1.5 with instructions to wear them atall times except on missionsto other islands. A similar group of badges was issued on Japtan. These films were developed on D+3 days 10 hr. The films indicated for Parry a mean doseof connected with tests Dog and Easy, Thetotal radiation exposures will be higher than those given by about 1,600 mr, which is the estimated average integrated exposure received from the fall-out after Dog shot. Film badge exposure data was available from 2,323 individuals and showed an average radiation dose of 355 mr. Excluding the three films mentioned in Sec. 2.3, the total doses ranged from 0 to 4,700 mr. Figure 2.9 showsthe distribution of doses and indicates that a large number of persons received doses from 0 to 100 mr. This was due to two factors: First, Seana stEEEOn Setellos © oe rave equine tT