FORECAST Fe.LL=OUT PLOT
(5) Starting from ground zero ond going out 15 to 20 milcs on the
fall-out plot of the 125 micron particle, draw cn arca of approximutcly 150 to
200 squarc milcse The line bounding this arca has a value of from onc fifth to
one tenth of the valuo obtainod by Equation 1. If the winds aloft are lew in:
speed (5 to 20 knots) thon this arca will be highly contaminated.
If the winds
aloft are stronger (30 to 80 knots) thon this arca will be smollor and not as
nighly conteminnted.
(6) In thoevent that the tropopause is lower than 35,000 ft. msl,
she fall-out will bc somewhat grceator than indicated above and the time of fall~
wut of the maximum contamination will be two hours or less for a 10 to 40 kT
tcewor shote
If the tropopause is above 42,000 fte msl, the full-out will be less
+nan indicated, and the timo of fall-out of the maximum contamination will be thre<c
hours or more after H-houre
(7)
Normally the maximum fall-out arca will be in a radius of from
49 to 80 milcs from ground zero, depunding upon the dircetion ands peod of the
If the winds aloft arc rolatively lew in speed (10 to 20 knots) the
winds cloft.
sull-out in the immediate vicinity of ground zero will be greatcr end the “dish=
cut aud "missile" fall-out within 10 to 20 miles of ground zero will be much
grostcre
Therefore at PG,
in the event of a 10 to 30 KT 300 fte tower shot,
Groom Mince will bc most likely to get contaminated with a 2 to 10 rountgen
intcgratcd infinity cose if the winds are from the South, S.: or West ond week. In
the event thet the wind specd cloft is high (40 to 80 knots) then the meximun
fall-out arca will throaten towns such as Tonopah, Cralicnte, Fiochc, Pannea,
Crystal, Hiko, ilemo, St. George, ctce The towns mcntioncd above may reecive
from 5 to 30 rocntgon intcgratcd infinity dose from 2 15 to 40 KT, 300 ft. towcr
shot. The most important factor in rcducing intensity of fll-out is unguler
wind shcar.
If the winds aloft arc moderate tostrong and the shcar is large
(90° to 180°), thon the fall-out will be minimal, sines th. contamination will be
sprced over a larger arene Diy, T:vada {5 aporoxinately 179 niles from ground
zero, honeo 14 wlll not come under the patirun fall-out, It wiil reacolvoe fren
Ce5 to 2 rocntron integratod infinity doze. Howovorys Hiy, lovadea will probatty
receive two or three such doses in viow of the prevailing winds at NPC.
(8)
The following exemele will be worked out in dcteil to illustrate
the proccdure outlined nbove. Wind informetion obtcined at 0339 FST, 24 liarch 195.)
Cloud hcight estimeted at 43,000 ft. msl, tropopause hcight, 40,000 M, ecquivelent
KT from 30 to 40 KT.
Level
Wind Dircetion
and Speed
BO00 ft
80G0
106,000
12,000
14,000
16,090
120°/05 knots
1409/14
180°/16
190°/14
200°/14
210°/10
20,000
25,000
30,000
220°/18
230°/27
230°/27
40,000
250°/36
13,000
and Dircetion
Factor
120°/0.8
409/243
180°/267
190°/2.3
200°/2,3
210°/1,7
220°/2
220°/:..7
236°/tet
210°/12
230°/8e1l
2:20°/503
240°/26
st
This pleces the maximum falleout at 42 miles from ground zoro on borring or 32°.
The maximum integrated dosage is, from Equation 1,
o
a+ +n
35,000
‘Moighted ind Spocd
uNultiplicetion
( 30 «
A. = —
_B
=
)
pes
( 30670) os
Ds
( 30+14 -1) 2
5
30 r intcgrated
rocntgens
y2
80 rocntgens
_
“a
111 Ge at & per wre,
emp
na
-.
ae
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