To compute the optimum exit time from a fallout area, you must be able to:

1.

Determine the time of detonation.

2.

Determine the location of an uncontaminated area.

3.

Determine the average transmission factor.

4.

Determine the time required to evacuate the fallout area.

5.

Perform the optimum time of exit computations.

When moving from a fallout area, the unit should move to an uncontaminated area. The NBCE collects

data about the nuclear burst, plots fallout predictions, and posts monitoring reports. As this collection

effort develops, the NBCE will be able to advise the unit when fallout is complete and where the fallout

has landed.

When moving from a fallout area, the unit should move to an uncontaminated location. This will

necessitate waiting until fallout is complete, to determine which positions will be uncontaminated.

The average transmission factors of the fallout shelters and the vehicles used to leave the contaminated

area should be computed. If data are not available, the transmission factor of a vehicle may be estimated

using the values in Figure S-1 in the Supplemental Booklet. Since all shelters will not be the same, an

average value should be used. A unit moving on foot will be fully exposed and have a transmission

factor of 1.0. Computation of transmission factors as taught in Lesson 1 should be done for shelters and

vehicles where there is no published transmission factor. The average transmission factor is computed

as shown in the example below.

EXAMPLE PROBLEM: Company A is located inside a fallout area and must determine the optimum

time to exit the area to restrict radiation casualties. While awaiting the exit time, personnel will be

inside these: armored personnel carriers (APC) - (TF 0.3), foxholes (TF 0.1), and the first floor of a

frame house (TF 0.6).

When the unit departs the area, personnel will ride in these: APC (TF 0.3), 2 1/2-ton trucks (TF 0.6),

and 1/4-ton trucks (TF 0.8).