to produce 1.0 rad.
“Btep 1. Determine the dose rate an the day of intake of 13
to produce 1.0 red to the thyroid.
D=.R Where: D = dose (1.0 rad)
Ae
R © dose rate on initial day
Ae 5 effective decay constant (radiological
and biological)
1.00 =R
0.09
R ® 0.09 rads/day
‘
Step 2.
Determine the number of microcuries of y131 to produce
0.09 rad/day
X(uc)(2.2 x 10°)(60 x 24)(2.6 x 1075) (0.22) =
|
(3.00) (20)
.
X = 0.16 Heto thyroid
(0.16) (5) == 0.80 po 1232 ingested
Step 3.
Determine relative doses from 7131 ang yehort
according to Graph Three."
At 48th hour, the relative contribution te total dose
from I> and T°T* 46 spout1 .
Therefore, ingestion of 0.4 pe 3+ (equivalent) at 48th hour will
produce 1.0 rads to thyroid.
Step 4.
Determine the number of microcuriesaf fission producte
required to yield the required I’>+ activity. At 48th
hour, r3 constitutes about 2.35% of total activity.
Therefore,
0.4
O,0a3 © 17 ne of fissicn products.
e
777
DOE ARCHIVES
54