.
«
e~
apr
paren ow. =~ 1sSe
Rear +
Be
:
RF
"Procedure ‘for- Ground Forecast of Fall- Out Contamination from ?Zominal
Forte Exploded at NPG from 300 {ts Towers.
Dy rieciable fall-out).
{1)
‘
mo
.
(Notes adr,", GFOpS do not _broduoc any
‘
th
126407
, i
,
,
Locetion and Intensity of eximum
|
ae
noe
In order to find locetion and intensity of maximum fall-out crea
necune that all of the activity of the bomb is located at a point somewhat lowcr
;
than the center of the mushroom of the atomic clouds Then follow the trajectory
cf a 125 micron particle whose density is 2.56 gn/om » This proccdure is recoms
ndaed since the NND of the soil et NFG is between 100 to 150 microns.
the
This means
the particle 1s located approximately 7000 fte from thc top of the ‘mushroom
cid fells with the spced of 15,000 ft. per how down to 20,000 ft. msi, and at the
rate ef 12,000 ft/pr from 20, 000 ft. down to the ground.
This is based on Stokets
Lew and the difference in rate of fall is due to change of viscosity of the air
we
“with temperatures.
Using the above data it is possible to locate the maximum
call-out. orca on a mape See paragraph (8) below for detailed analysis of the
vsthod used to obtain the location of the maximum fall-out arene
It should be
sited that the maximum fell-out occurs Lotween two to three hours efter i!l-hour
.ca the averaze cloud rises to approximately 40,000 fte msle The actual time
cf felleout depends upon the terrain, the height of the tropopause and the <juivae
cenit KT of the tombe
In the event that the maximum fall-out from a nominal temb"”
ccs not oceur within three hours, then the fall-out will be gencrally less cons
ie cinating.s If the maximum occurs in 1} hours or less
ss the fall-out will te jute
We
intenso and highly conteminatinge -To evaluate the maximum fall-out using iste
Wee:ted
Infinity dose in rocntgens, the followving cnpirteal relation nay beocraeds
{ :
fe
:
:
t
™
NG
N74
¥
+3
! Root
if
5
Es
B
Tre re
id
i
Yt
83
e
‘\) :4
Ie
sa
p=
“ow:
3
,
ms
10,000 ft. to 40,000 fte msle
. *
4k
nd
RG
326 US ATUL BERG
COMMIS tpt
2 ‘maximum wind speed shear from 193090 fte to
‘L
pcation,Whe
fi
_—
(800000 fte msl.
he
pon}
rey’
3 2 zs
§
3B
) y/i8 - - - - Equation 1
wD
a
°
As AW 3 maximum anguler
wind shoar in the rerion
fron
hs
gu
° de ‘ib 1
e
.
=
S43 ‘2 S7
ag 4 as) £
ou & 2
sug
(30-_4
—~s
yNidk
Np? Spe
Collection- 4
Gy WAZAZ
ry
:
Polderlatlleof S
“
.
ce
\é
(2) The arca covered by. ‘the different; integrated dose linos may te
~ ctfeined as follows:
a
.
we
nen = ee
LH f
@
(a)
The arca of the meximum fall-out given ebove ts very
vali.
It is so small in fact that it may be taken ns a pointe _The value of this maxinun
fall-out point is given by Equation le
(>) round the maximum fall-out point draw an cllijsc ahose
arca varies between 150 to 300 square milcse The mejor axis of the ¢ll{rso will
be drevm parallel to the fall-out plot of the 125 micron particle «s sh}..n in
rerscraph (8) below.
That focal point of the ellipse which is nearest 4 ore und
zero will be pleced at the theorcticel maximum fall-out point.
Tho cuter to ndery
N\
&&
DATE
CONFIRMED TO BE UNCLASSIFIED
of the ellipse will indicate tho integrated isodose line obtained Ly dividing the
veluc of Equation 1 by approximately 4 or Se
(3) SimSlarly, an elliptical arca of from 500 to1000 squarc niles
will be drawn about.the maxinum fall-out points The integrated.dose value of the
line bounding this.Brea "ts"aes
one tenth of the value“obtained ty using
(4) Starting oe Ground Zero. and usingthe ‘eee Flot of the 12F
(7> r.icron particle indiccted in paragraph (8) as a guide, drew a rectangular arca of
/
fror, 3000 to 5000 square milese Then proceed ‘to fit this rectangular trea t round
K
ground zero and around the maximum, fall-out point samcwhat as indicrted In porae |
grerh (8) bolows The line boundingth
‘this’ area hes evolve.ofapproxizetely
a
one
Sticth ef the value obtained
:
aafatten
gone0D0F
LANL RG 7
/