SUBJECT:
“ams
Radi .ogs.i1 Survey of Downwind ..toli_ Cor. sminated by BR..VO
that one survoy meter could not be properly zcro adjustod.
The four remining
!N/PDR~39, still operated cfficicntly and secmed to be in good working ordcr.
Onc (1) cach Beckman MX-5, and one (1) cach AN/PDR-27A was brought alory
for any low intensity checks necessary.
Two (2) cach calibrated AN/PDR-T1B, wore
on hand to scrvo as sparcs in the cvoent of opcrational failuro with the tN/PDR-*”
None of thesc instrummts wero requircd,
6, The average and maximum gamma dose ratcs moasurod on the various islance
of cach atoll arc plottcd in Figures 1 through 5. All measurements were mde at
waist height unlcss otherwise indicatcd, The mximum readings do not includo
measurements made with the instrumcnt next to a contaminated surface.
Detailed survoys were made of all the inhabitcd localitics, Typical
readings are given in Tables 1 and 2 for the nativo villago of Rongclap Island,
and the TG 7.4 camp on Miwctak Island. In gcencral, tho villages and the camps
appearcd te have slightly lowcr averago dose ratcs than the romaindcr of tho
island, This can perhaps be ascribod to different gcomctry of tho contamination
and to slightly grcatcr penctration into the leoso gravel in the nativo villages.
The dose ratcs inside the nativo huts appcared to be almost the samo as the dose
rate outsidc. The dose rate in the middlo of the military barracks, tcnts, and
shacks wes 1/3 to 1/2 that outside, This reduction is probably largclyg gcomt
effect.
The dose rate foll off rapidly on the beach bolow the high tide mrk.
There was no cvidence of rain washing off the contaminatcd mtcrial.
The foilag
on the windward sides of the islands appcarod to be slightly above average con-
tamination.
BEST AVAI
L
COPY
BLE \<
TYPICAL READINGS IN RONGELAP VILLAGE —~ 8 MARCH
Location
Dosc Rato (ar /nr)
Rongclap Island (avcrage)
375
Near central cistern
Near southern cistern
Near northern cistorn
300
220
350
Center of village
280
TABLE 2
SAN BRUNO
YO ERC
TYPICAL READINGS IN CAMP ON ENTWETAK IS. - 10 MiRG
.
Location
Outside Dose
Inside Dose
Rate (mr/hr)
(ar/hr)
Eniwctak Island (average)
280
~-
Tent, cdge of min camp
270
175
Mess hall
Latrine
Sleeping quarters
Dispensary
220
“" 260
260
220
110
_