I.
UNCLASSISIED <sexcneEeE
HONGELAP (ND AILINGN.S (CONT'D)
6
began to apoear when the instrument wes within about six inches from the roc “)
it seemed unlixely that dceccntaninaticn of the roof would effect any substan e347
125
vn
reduction of exposure cf inhabitants in a mut,
A crude attenpt was mads to ascertain depth of penetration of radioactivits
in a patch of soil naar the center cf the village.
The plece chosen was 2
tare patch of locse scll in a grassy area, Successive layers of about me
inch in thickness was secoped up, each layer teing mit in a seperate can, anc
then the radiations from the cans were comapered on the beach where the background was much lower, The third layer had no datectable activity; the first
layer had about six tines the activity of the seed.
It is quite cos
that all of the activity in the second layer may have come from spill:
during remcval of the first layer, aAn effort was made to ecllect
thinner layer. The technique wes even more unsatisfactory, but the result
indicated that the activity per unit velune was several tines greater int
thin layer than in the first inch. me can ecneclude thet there wes very
little if any activity belsw two inches, and that the activity may te entiraly
superficial.
5.
DECCHTAMINATICN:
Since the state af the vegetation and the cisterns
indicated that there had teen little if any rain on the island, an attecrct
was made to find cut whether future reins aight effect any natural decentaninétion. The ship's crew meunted 2 tortable gasoline-driven water-pume on tie
beach, connected 2 hese, and sprayed salt water on the thatched roof of cne
hut, and on a neighboring gravel area. The contact reading con the rocf cf
the hut was reduced by 10% (after suctracting the generel cackgreound {ria
amin
of th
the readings, this indicates aperexinat ely
but there wes no noticeable reduction in c
mat or cn the washed-—down gravel 2re2. while
regarded as conclusive, it suggests that one should
the effect of future rains,
It should be noted tha
en this subject is conflictin .
i
G =
<
,
just pricr to George Shet hed Little effect on the Dog Shot fall-qit, Sut the
raing that fell owsd soon 2fter the cecarturm of the Task Force 2tresr te have
been fairly effective, However, even if the experience had teen consistent,
the terrain surfaces 2t Reongelap ind Eniwetock are so different that it would
be unsafe to draw eemclusions.
It was evident thet any attempt at artificial decontaninstion would
difficult and very expensive relitive to
ec
elsewhere until radioactive decry has reduc
i
level. Deccntamineticn operations of the < ype used cn Entiwetck Atoll?
dozing and yeading) would not bee arplic3 x
se of the total destructicn
2 thin topsoil in the area covered.
of all vegetation and severe
or
&
a
Any
teascnabdle acn-destruccstive de cotaminaticn effort would have to de 2
manual iob.