SECTION 3
DOSE CALCULATIONS
To determine the dose to personnel, consideration is given to the time spent

topside (outside) and below decks (inside) and the radiation protection afforded by a
ship or building.

The daily, free-field integrated intensities (topside and below) from

Section 2 are adjusted to account for crew activities, either documented or assumed.

The daily exposures (mR) are then converted to film badge equivalence (mrem).
Results are presented as a daily cumulative dose to personnel through 31 May 1954,
when the CASTLE roll-up phase was nearly complete.
3.1

PERSONNEL ACTIVITIES
An estimate of personnel movements is critical in determining a film badge dose,

especially during fallout deposition and at early times when intensities are relatively
high and intensity levels are changing through decontamination. As inferred from deck
logs and after-action reports, normal crew activities were somewhat altered during
the day that Shot BRAVO fallout occurred.

By the following day (2 March) normal

crew duties were generally resumed. Because intensity levels were still relatively high
on some of the ships, it is necessary to account for specific periods of time on deck in
order to calculate personnel doses. Shot ROMEO fallout, on the other hand, peaked at

approximately 9001-2400 hours, 29 March, on nearly all of the ships anchored in Bikini
Lagoon.

Rad-safe measures, such as turning on the ship's washdown system, were

generally accomplished at a time when virtually all of the crew was already below
deck.

By the time crews were mustered at approximately 0800, shipboard intensity

levels had been reduced to where normal crew duties could be resumed without too
many restrictions. Hence, it is not necessary to detail personnel movements onboard
the task group ships following Shot ROMEOto estimate their dose.
With the exception of 1-2 March, when actual times topside and below are used,

the integrated intensities topside are multiplied by a time-averaged shielding factor to

account for the time spent topside (outside) and below (inside) during a typical work
day.

It is estimated that the crew on each ship was on deck at the following times:

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