Chapter 3
RESULTS AND_ DISCUSSION
Aiter Shot Wahoo, GITR data was obtained only on DD 593, because power failures on the other
two ships prevented receipt of the radio timing signals. After Shot Umbrella, GITR data was
obtained on all three ships, although some data was lost because of shock damage to several
instruments; in addition, the majority of the GITR’s were manually started at H-3 hours to
circumvent possible repetitions of power failure. The manual starts created some uncertainty
in the timing of most records, and as a consequence caused laborious time correlation of doserate curves with those few records obtained from radio-started stations.
3.1
TOTAL DOSES AND DOSE RATES ABOARD TARGET SHIPS
Detailed tabulations of fllm-badge and GITR data are presented in Appendixes C and D.
3.1.1 Weather-Deck GITR Data.
After Shot Umbrella, the peak weather-deck dose rates on
DD 592 and DD 474 exceeded the normal capacity of the GITR detectors, i.e., the detectors
were temporarily saturated.
To fill the resulting gaps in the averaged weather-deck data for
these saturation periods, data from several unSaturated interior GITR stations were normalized
to fit the averaged weather-deck dose-rate curves on both sides of the gap. The interior GITR
Stations (which supplied the data used for normalization) were selected on the basis of similarity
in the shape of the candidate dose~rate curve with that of the averaged weather-deck dose-rate
curve in the vicinity of the gap. With this criterion, two sets of normalized data (used consecutively) were required to close the gap in the averaged weather-deck dose-rate curve for DD 474
(Figure 3.1). Estimates of average weather-deck dose were obtained by numerical integration
of the filled-in dose-rate curves.
Averaged values of the total dose rates and doses on the washed weather decksof the target
ships (and estimates of the standard errors) are presented in Figures 3.2 through 3.5 as func-
tions of time. The averages for DD 593 (both shots) do not include the data from GITR Station
1; the data appeared to be anomalously high when compared to the data from the other weatherdeck stations. No reason could be found for this apparent anomaly, although the data and calibrations were rechecked. If the data from Station 1 were included, the average doses and dose
rates for the weather-deck areas on DD 593 would be about 1.3 times higher than shown in Fig-
ures 3.2 through 3.5.
Figures 3.2 and 3.3 compare the weather-deck radiation histories of the three ships for Shot
Umbrella. The dose curves show the rapid buildup of dose aboard the two close-in ships.
Because radiation histories for Shot Wahoo were obtained only on DD 593, the averaged data
from the weather-deck stations on DD 593 for both shots are presented in Figures 3.4 and 3.5
to permit comparisons of effects at Similar distances from surface zero (i.e., 7,900 feet for
Shot Umbrella and 8,900 feet for Shot Wahoo).
The curves (Figure 3.5) showthat the dose for
26