tamination was found in regions which confirsed the forecast cloud tre-
jectories, the requiresent for R‘24 through 2448 hour tracking coverage
was cancelied.
As @ result of the repart from Rongerik, the advisory to CIUSFASFLY
at 2000 hours B Dey incladed mention of fall-out at Rongerik plus einer
fall-out at Rongelap and other nortbern Marshall Islemis. The fall-oct
wes attributed to an BY12 hour change in the forecast air particle trejectory for the twenty thousand foot level. This trajectory, forserly
moving toward the EXE, was reforecast to move toward SE in a circular
clockwise path through south to west. The CISCPACFLE advisory incladed
po health hazard problem for surface and air routes, but that fall-out
onBikiai-Atoll, as well as danage to structures, wuld delay reastry ser
e&
Gaya.
,
During the trip back to Eniwetok on the night of B Say, the fleet en
countered a wide area of finely divided (arparently less than § micron)
particles which caused top-side intensities as high as 350 ar/sr.
App
ropriate measures were instituted by the Navy Task Group Commander to the
affect that all personnel not essential to cpen deck duties would resin
indoors. Ship's weather doors were closed and the washiown systeas cope
rated intermittently to told down the levels.
Based on the advisory from the weatber detachrent that their instrue-
ment was off-scale, the Air Task Group, om the morning of Bf] day, sent
a ponitor by axzphibian aircraft to check the Rongerik situation. This
monitor upon arriving over Hongerik, reported the atoll contaminated end
requested permission to start evacuation of personnel. At adout 1300
the monitor reported readings on Rongerik of 240 ar/br at 250 feet ant 3.2
r/or one inch off the ground. The Rongerik evacuation was complete! in
two segments, the first group (8 people) coming out by 530 bourse and the
second group (20 people) by B35 hours.
The special AEC/RYOO Kwajalein Flight ABLE, requested the pevicas
right, had been instructed to make an in-flight report upon reaching Taongt.
(4 preliminary Flight ABLE report indicated 1350 m/br on the ground at
Rongelap, 445 mr/hr on the ground at Ailinginee ani zero for Rotho.) dco
comdinzly, it was decided to start a destroyer on the way to Rongelap iz-
rediately and to set up a Shol6 amphibian with monitors to check the sur
face comiitions et Rengelap before dark. The destroyer was directed to
be off Ronzelap geady to start evacuation at dawn the following day. 4
Trust Territery
esentative with interpreter was requested to move by
PEN fros Xwajel@@a
set up, two >
to arrive et Rongelap at the saze tine.
The Si-15 was
{ble conitors were especially triefed to cake reaiings
at waist heicht, use several meters of the same type for comparison ant
to use 4ifferent types for cross-check.
An average reaiing of 1.4 r/iz
cade in the living ares of Ronzelap Island by these monitors was used in
the decision the saze night to order the destroyer to commence evacuation
cperations at dawn.
Evacuation operetions began about 0730, J Mareb and