Carl Buckland, H-1
Cetober 20, 1961
W. R. Kennedy, BS
410584
"CLOSE IN FALLOUT” FROM CASTLE BRAVO
x-6
The followiug measurements were mace at various tims at the places indicated
following the March 1, 1954 datonation at Bikini Atoll.
Speed of moveaent to
all points is based on a measurement by a recording garm meter located om
Eniwetax Island, Rongerlx Atoll.
The meteor indicated start of arrival at
H + 7-3/4 hours, with an estimted peak reading at H + 8-3/4 hours.
~
‘Tha
distance fs 135 nautical milez, so a mean speec of 17 knots a been used in
the calculations. Extrapalated decay has been based on the
*? rate. Ho
aliowance bas been mide for weathering prior to measuremmt, so the valuss
ere probably low.
The bomb was a surface burst of 15 Megatona, 530% fission.
The “hot line” ofp
the fallout pattern was somevhat to the north of all the locations listed
below.
Kabelle Island, Roagelap Atoll, is the closest to the “hot line”,
but still probebly somo distance from it.
Island
Location
Deate-
time
Rongelap D+7
Reading
Distance
375
103
H+6
nr/hy
seu miles
Etimted
Arriysl time
Es timted
Peak reading
Estimted
D -
£0 R/hr
&0 R
Kabelle
D+25
1000
105
H+ 6.35
235 R/nr
7500 RB
Enivetg:
Utirik
D+ 7
D+ 3
280
170
135
276
K+8
H+ 16.2
li R/br
1 B/nr
Lio R
G1 R
VAY Snead phy
WALLIAN Ho Eis stet o
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