The **average n **can be used to compute nuclear data in areas of nonstandard decay created by a single

nuclear burst. When dealing with overlapping contaminated areas caused by more than one nuclear

burst using an **average n **value for the overall pattern could lead to serious error. Fallout produced by

more than one explosion will normally have different decay exponents at different locations within the

area.

The following methods are applicable to two or more overlapping fallout patterns. The choice of

method is dependent upon whether enough is known about each burst to separate the dose rates

contributed by each.

Separate the contributing dose rates. This requires that H-hour of each burst be known and that two or

more dose rate readings be available for the location of interest after the fallout peaks and prior to the

arrival of new fallout. Normal procedures for calculating the decay exponent **n **for each contributor at

the location of interest are used. Calculate the total dose rate for a specific location at any time in the

future by calculating the dose rate at the desired future time for each contributor separately and adding

the results. Repeat this process for each location of interest within the overlapping fallout patterns.

EXAMPLE PROBLEM. At a location where fallout has been received from two detonations, one at

0800 hours and one at 1100 hours, the following dose rate readings were recorded:

Time

Dose rate cGyph

0830

160

0900

100

0930

61

1000

44

1100

27

1130

462

1200

219

1300

108

Predict the dose rates at this location for 0800 hours in 24 and 48 hours (H + 24 and H + 48 hours) after

the first burst.

Solution: Sufficient data are available to separate the two contributors.

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