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ASSEX IT
Calc:lationn of Tose Rate at Tiree Feet Above A Flano Surface

For point source (0.3 ~ 3,0 Nev rance)
Tose rate (r/hr) = oh
C = activity (curies)

where

TP

ew

fe

ee

SR

we

ee

E = enerry in lev
d = cistance in fect

ote

wwe

eee

Dose rate ~ GFA 27rdx

he $ x2

where: A = activity/untt area

h wz height above surface (feet)
xX = distance in fcet

Ra

.

a es cane

40K
Tose rate = era “\ phe

crus
nasi

we

ne

ee

eee

ee eee

eeee

The rcean free path for 0.7 Mev in air is cbout 3M feet co that

ascentially all ef tue dose will be contributed fron a surface 1,000

feet in vadiuga,

tet A= 10 x 10° crries/rt2
= 0,7 ev

Tose rate = €7°(0.7)(10 x 0) raf gic
by
~/

= 2,2 mcfhr

Since tig forcula assures no abcocption end also a uniform plane
urface, an estirate is tat

10 pele? ——>1:isfir,

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