le
is 1.2.
The integrated average /S/ Y ratio for the first 120 days
Calculate total disintegrations per square foot from arrival
time to 120 days after burst by integration.
Divide this number by 1.2
to give total © disintegrations in 120 days.
2.
In Appendix C it is calculated that at 120 days, there are
1.62 x 10° atoms that will undergo gamma decay for every d/m at 120
days.
Calculate the @
d/m at 120 days and multiply by 1.62 x 10° to
give total & disintegrations after 120 days.
3.
Add land 2 to obtain }_N in the expression
Dose = 6.6hx 107° $>N
millirads
If a time differing from 120 days is required, the relationship is shown in
Fig. 2.
Example of Suggested IBM Calculation
Assume
Burst Date
087
Sample Date
O91
Count Date
097
Activity on 097 = 104 a/m/rt2
1.
Total p disintegrations - Sample date to infinity
Ny
7200 a,
(te - thy?
(ts . ty )0-2
(7.2 x 103)(104)(10)?*?
(14)+?
8.68 x 10° a/et2