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DATE

TIME
o8soo

Uy

5 MAR

ogo

9

8.

6 MAR

0800

6

7

12

7 MAR

0800

4

5

10

8 MAR

0800

3

ho

l, MAR

cpsy

17

20,

ou

8

These three ships are chosen as examples because the BAIROKO and PHILIP were the

most heavily contaminated in the beginning, and the GYPSY (ARSD 1) was the most
heavily contaminated one week later, It is believed that contamination clung -

to the GYPSY longer than to other ships because of the condition of her topside,
which was quite rusty due to her recent heavy employmert without adequate
opportunity for unkeep,

Another factor tending to increase radioactive intensity

on the GYPSY was her recent employment to recover contaminated chains and moorin,
gear from the bottom of the lagoon,
|

5. Three (3) barges, ten (10) LCUs and ten (10) LCMs were anchored or moored in

the southeast portion of the lagoon off ENYU Island (about 20 miles from ground.
zero) prior to the detonation, as it was not considered practicable nor safetq

take them to sea -in the prevailing weather, (BELLE GROVE (LSD 2) had eighteen |
(18) -other LCMs and one (1) AVRin her well at shot,time), These craft left in

the lagoon suffered no damage from blast, heat or wave action, but all were --

heavily contaminated by radioactive fallout to such exterit that about twelve (12).

hours after shot time, they had a radioactive intensity averaging several roentgens
per hour,’ Subsequently, all were washed down with hoses from, other vessels. (the

high pressure hoses of GYPSY proved particularly effective as (PSY was maneuvered
successively in the close vicinity of these craft), followed by a thorough |

‘decontamination by additional hosings and scrubbings by decontamination personnel

who, by this time, were able to board the craft. All these masures were _.
sufficiently effective that average radioactive intensity of these craft is now

only about two (2) mr per hour (gamma only). .
6.

By three (3) days after the shot, all the water in BIKINI Lagoon had become

slightly contaminated with radioactive material. Contamination was of the order
of one microcurie per liter, Fortunately, drinking water produced by ships °

evaporators from lagoon water has shown no activity.

The salt water systems, such

as evaporators, condensers, fire mains, etc,, on most ships became gradually contaminated, and at one time it was feared this might become a major problem...
However, ten (10) days after detonation the radioactive intensity of the salt water

system ceased to increase, and at the present time this intensity is decreasing,

The highest intensity of this kind detected was 30 millircentgens per hour (gamma
only) on the exterior of an auxiliary condenser of USS CURTISS,

The average

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