Intensity levels below are estimated using a ship contamination model that is

dependent on radiological decay rates and the rapidity with which hulls accumulate
contamination. The decay rate of pts that was used for Operation CROSSROADS is
applied in this report, but an estimated uncertainty in the exponent of 10.2 is also

considered. This variation is of the magnitude that thermonuclear devices can exhibit
within days after detonation.

By influencing the parameter S described in Section 2,

the steeper decay rate (t7 1.5) results in larger contamination doses for all ships. In all
cases, the variation in dose with decay rate is within a factor of two.

Also as

determined for Operation CROSSROADS, saturation of ship hulls occurred within the
order of one day.

Estimated limits for the time to saturation are 0.5 and 2 days. For

all ships, these saturation times influence the contamination dose by less than a factor
of 1.5. The combined uncertainty from decay rate and saturation time, approximated
as a normal distribution, is shown for each ship below at the estimated 90-percent
é

level.

Ship

-

Ship Contamination Dose

APACHE

0.43 + .17 rem

BAIROKO

0.20 + .09

BELLE GROVE

0.24 + .12

CURTISS

Q.17 + .10

EPPERSON

0.12 + .06

ESTES

0.16 + .07

LST-762

0.16 + .07

LST-825

---

LST-975

---

AINSWORTH
GYPSY
LST-551
-

0.27 + .13
0.31 + .12
0.21 + .08

NICHOLAS
PHILIP

0.19 + .10
0.63 + .4

RENSHAW

0.44 + .3

SIOUX

0.64 * "0
155

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