Determine the average transmission factor for the unit while in the area and while leaving the area.
Average transmission factor while in shelters (As).
Average transmission factor during evacuation (Ae).
PART B: COMPUTE THE OPTIMUM TIME OF EXIT FROM A FALLOUT AREA
The time to load on the vehicles and move out of the contaminated area must be estimated. In order to
minimize exposure time, it may be necessary to temporarily abandon nonessential items and recover
them at a later time when the dose rate has decayed to a lower value.
Perform the Optimum Time of Exit Computations.
After having determined the required information, you can perform the optimum time of exit
computations. These abbreviations are used in the optimum time of exit computations:
As = Average transmission factor for the fallout shelters.
Ae = Average transmission factor after leaving shelters during movement out of the area.
Tev = Time (hours) required to move out of the contaminated area.
The optimum exit time is computed by the three following steps: