4.3
DOSE CALCULATIONS FOR USS COCOPA (ATF-LOL).
Dose calculations for COCOPA on 1-2 March 1954, when BRAVO fallout was
encountered,are detailed below. Time periods below deck are indicated by an asterisk (*). After
2 March, the daily film badge doseis calculated by multiplying the contributions to exposure, both
topside and below (from table 3.3), by the appropriate time-averaged shielding factor or
apportionment factor. Contributions from each source are summed and converted to a film badge
dose. Cumulative film badge doses are given in table 4.3. Dose calculations are carried out
through 22 June 1954, when dose accrual falls below 1 mrem perday.
Integrated Fallout
Intensity (mR)
x
Ship Shielding
Factor
=
Adjusted
Davy
Time Period
Exposure (mR)
1 March
0000-0600*
0
0600-1200
0
1200-1330*
5.0
0.1
0.5
1330-1700
51.7
1.0
51.7
1700-1800*
42.0
0.1
4.2
1800-2000
166.6
1.0
166.6
2000-2400*
362.5
0.1
36.3
627.8 (table 3.3)
259.3
1 Marchfallout dose = (259.3 mR) (0.7 mrem/mR) = 181.5 mrem (table 4.3)
2 March
0000-0800*
476.1
Q.1
47.6
0800-1200
98.2
1.0
98.2
1200-1330*
30.0
0.1
3.0
1330-1700
70.0
1.0
70.0
1700-1800*
19.0
0.1
1.9
1800-2000
2000-2400*
36.9
1.0
36.9
_65.7
0.1
6.6
795.9 (table 3.3)
264.2
2 March fallout dose = (264.2 mR) (0.7 mrem/mR) = 184.9 mrem.
Dose from shine and ship contamination = 18.3 mrem.
Cumulative film badge dose through 2 March = 385 mrem (table 4.3).
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