Tras, it can be readily understood that readings of two different
Gnetrumenta in the sane gamma field aay be different and even two
overlapping scales of the same instrunent my not agree.
The size of the islands surveyed within the range of this study .
apparently does not effect the validity of the sitituds 4o ground
etensityconversion curve. Calibration fur the SCINTAMETERS waa
perforned over areas of various sizes including both small and
large islands in tre Eniwetok and Bitcini atolla. Data from these
sewerel locations agreed very closely.
Obviously, judgement is needed in evaluating radiation intensity
or
in terma of potential exposure whether ground measurements
Mettawa atl RutatA) res eae intamenannaagece cot easel
of the SCINTAMETER at 9,7 Hav," the aver
age of gamma fission product activity, ia about 60% greater than
both the TIB and the 27¢ internal probe and about 100% greater
than the 27C eaternsl prove.
sha eased an
“
Figure 30, the response
Ve
EFFECTIVENESS OF MONITCRING PROGRAM
The aerial surveys and the automstic monitoring network muat be re-
viewed together to analyze the effectiveness of the program properly
for they were designed to complement each other. The program was a
Practical compromise between two extreme monitoving methods, one be~
ing a monitoring network comprised of stations on each of the islands
included in aerial survey patterns (66 in the Marshallese, Carolines,
and Marianas} or tho other being daily or more frequent flights over
each of the survey Datterne from D ¢ 12 repetitively for a number of
days following each event.
It is believed that the monitoring program did successfully fulfill
the basic requirements of providing timely faliout information con-
cerning the Central and Southwest Pacific and of documenting cusmlat ive
radiation in those areas. ‘The {sforwation developed by this systen
following the BRAVO ourst is an excellent illuatration of ite effectivenesa in performing the former function.*
aerial measurevents are the source cf datas
*At 15,0 M cn 3 days the autoxsatic monitor on Rongerik, 130 NM Bast
of Bikini, went off scale.
(Maximus acale reading te 100 ar/ir).
This information, received at the Task Force Headquarters aboard the
Bates at about 1600 M, was the first indication of excessive fallout
outaide of the ships of the Task Force and Bikini atoll itself. A
radsafe monitor was sent with a scheduled island resupply flight on
the following saorning to clarify the fallout situation which had been
indicated by the automatic monitor. At 2000 M on B day, a message to
Squadron VP-29 was originated on the Estes requesting the iamediate
execution of flight ABLE. The request wa delayed until that hour to
diminish the
ibility of the survey aircraft paseing thru the radioactive cloud.(
Due to communications: difficulties,the nessage did not °
Clear the Estes for about twelve hours after it we originated and the
flight. did not leave Kwajalein. until about noon on 8& daysat 1535 &
on B41 the first inflight report way received from the
aircraft.
The report included measurenanta over Ailinginae, Rongelap, and Rongerik.
T confirmed neasarements of dangercos radistion aade on Rengerik by the
radsafa monitor a few hours earlier. On hig recouendation, evacuation
of Rongerik had begun immediately and was complete when the firat inlight message was received. By 2000 M the radiation intensities at all
atolls in the ASLE pattern ware known and plans were ‘“rmiated for the
evacuation of additional north Marshall atolls. By 2 #5 days, all sur
vey patterns had been executed including an faprovised pattern to survey
the Gilbert Islands and the extent and severity of contaminstion In the
Pacific were clearly defined,
.
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