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ABSTRACT
This report is an addendim to tha final Wport of Project U.1,
Operation CASTLE,
and
Its purpos3 is to consider the physical factors
dosinetry of the fall ae on the Marshall Yslands fras the first
ahot of Operation CASTLE
Data was summarize:
=
hoe.
fron field fiadiological Safety surveys,
fallout radiochemical stidtes, and fallout gamma spectral measurce
aentg, The influence of these and other facturs on an ovaluation of
gurvey meter response and total dose estinates waa considered, Estimates of fallout duration tines and enercy distritution of the dose
fron a plane source were made and the effect of diffuse source=goonetry, .
on the depth-dose to air~-dosa relationship was considered,
doses fram
Since
which data
atruct ths
soft parma and beta radiation were also
the fallout incident created an initial
collection was of secondary importance,
avont have been uncertain,
choof the
rather than exact.
Superficial,-
considered,
emergency dusting
attempta to meco?
cata was indicati
However, a fairly consistent estimate of external
gamma dosage was possible, ai thou gh the question of beta exposure
remains mostly unanswered, It has been assumed that no significant
neutron or alpha particle exposure occurred, Internal doses from in-
haled or ingested material and the bio-medical aspects of the incident
have been discussed in other CASTLE Project 4.1 reports,
It was concluded that: (1) the AN/POR-394 requires a correction
factor of about plus 20 percent in dose-rate readings mada under the
conditions described ; (2) dacay cf the 70.835 (3)th of the fallout is
believed expressible. by the factor of T
(3) the external gamma
dose was delivered primarthy by radiation energies of 100, 700, and
1500 kev; (4) the beta dose was delivered by beta radiation of maxinum
energies of 0,3 and 1.5 Mev, mostly from fallout deposited on the skin
itself; (S) the exposures occurred betwesn 4 and 73 hours after the
detonation = the fallouts were probably of 12-hmrs duration; (6) diffusa source fpeometry increased the midline dose by about 50 percent
caonpared to the midline dose which would have resulted from a hilatarel
narrow beam exposure of the same air-dose; (7) error in the estinates
4s believed to be less than 50 percent; and (3) total air ganna doses
were estimated as follows;
8l r; and Utirik, 13 r,.
Rongerik, 86 r; Rongelap, 182 r; Ailinginae,
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