D.
Pearl Harbor Radiological Survey
After arrival at Pearl Harbor Naval Shipyard at 071550 (H+175), the Atomic
Defense Officer
discovered radiation levels as high as 40 mr/hr (ref. 7) and
the crew was "evacuated to the receiving station" (100200) except for special détails.
Subsequent radiological survey (appendix A) revealed the following
general gamma backgrounds adopted here to a reference time of 120900 March, (H
+ 288 hrs).
6
oe
_vhile
Weather decks
Rogge < 5 mr/hr
Ship interior
Rogs < 1 mr/hr
.
.
2
appendix A lists specific items scattered throughout the ship which ex-
‘ceeded these levels, the average dose rates were probably below these levels.
Converting these dose rates to H+] unit reference rates (R, ) gives;
Ry (Deck) = 4.5 r/hr
Ry (Interior) = 0.9 r/hr.
E.
Variation of Dose Rate With Time
Two primary factors can change the dose rate at a given location. First,
radioactive decay which will be estimated by use of equation (2) for each of
the times of interest (see Table 5 below) and; second accumulation or depletion
of activity by physical processes.
Of specific interest here is the effect of
. the weather in removing some of the fallout which is assumed to have been deposited on PATAPSCO at H+32.5 hours.
Table 3 extracted from the PATAPSCO
. deck log summarizes appropriate wind and rain periods during the return trip
to Pearl Harbor.