ORNL-2106 - the Molten Salt Energy Technologies Web Site

i -
I
1
c
A
e
W
radius a (Fig. 5.3.6) is:
where
a u' cosrn 0 e-@ 217p dp
2
00
R 2c
1/2 .
e-*(:)
RdR
-
R2
e-Y dy
where
PERIOD ENDING JUNE 10, 7956
Em+1(4 = xm J - , t = distance from source to dose-measurement
Y ym+l pas i t ion
n/2 2n e: z (distance from lead) plus thickness of
u = jko j4=o u' cosrn 8 sin 8 de d+
lead (4.3 in.),
2m'
=- m+I I
p = linear absorption coefficient,
pl = average linear absorption coefficient along
the center line with duct in place,
p2 = average linear absorption coefficient along
the center line with lead in place.
c = flux-to-dose conversion factor.
The choice of the buildup factors B, and B2 is
very uncertain. It does not matter whether B1 is
These functions have been tabulated by Placzek2
for values of m up to 19.
taken for aluminum or water, but, since the water
If a is the radius of the duct and b is the radius
of the source below the lead, then the ratio of the
center-line dose rate with the duct in place to that
with the solid lead shield in place is
2G. Placzek, "The Functions E (x) = e-xp~-"
Jlm
dpsll MT-l (n*d*)*
= [
Em + 1 (CC 1') - 1 Em+l(plf) (1 + " 3Bl(plt)
(1 +g2
1
(1 +$)""
2 77