=
The YAGH,O was stationed 40 miles due north of ground zero,
out arrived shortly after H # 7 hours.
Fali-
The washdown was not activated
until a build-up of about 20 mr/hr on deck was reached,
This occurred
1 3/4 hours after the first indications of fallout arrival.
The fallout
ceased at approximately H # 21; the total time that the ship was in the
fallout was 13 hours.
|
The total dose under the washdown was approximately 150 mr, compared
with 34 r in the non-washed area,
The relative effectiveness of the wash-
down for this event is 96 to 97 percent far dose rate and 93 percent for
accumulated dose,
Discussion ~ Washdown
The nature of the fallout material is considerably different from,
r
that of tne(2220) shot, i.e., considerably less mass and averag=
v
ing smaller size, 30 micron diameter or less, and arriving in liquid droplets of high salt content.
The significant difference is that the fallout
material consisted of very small, solj@,
in aqueous suspension whereas
—.
radioactive particles of bomb debris
I(zuNt) material was mostly agglomer=
ate material heavy and much larger in size.