I. RONGELAP AND. AILDIQUE (cayT'D)
began to appear when the instrument was within about six inches from the roof,
it seemed unlikely that dscontamination of the roof would effect any substantia)
reduction of exposure of. inhabitents im « mit.
A crude attenpt wes mide to ascertain depth of penetration of radicactivit;
in a patch of sci] near the center of tha village.. The place chosen was a
bare patch of loces soil in a grassy ures. Successive layers of about me
ineh in thickness was scooped up, each layer being put in @ separate can, and
then the radiations fran the cane were conpared on the beach where the vack—ground was mich lower, The third layer had no detectable activity; the first
layer had about six times the activity of the second.
It is quite pcesible
that all of the activity in the second layer may have come fram spillage
during removal of the first layer.
An effort was mide to collect an even
thinner layer. The technique was even more uisatiafactory, tut the results
indicated that the activity per uit volume was several times greater in the
thin layer than in the first inch. One can conclude that there was very
little if any activity below two inches, end that the activity may be entirely
superficial.
5. DECONTAMINATION: Since the state of the vegetation and the cisterns
indicated that there had been little if any rein on the island, an attempt
was made to find cut whether future rains sight effect any naturel decantagination. The ship's crew mounted a portable gesoline-driven water-pump on the
beach, connected « hose, and sprayed salt water on the thatched roof of me
tat, and on a neighboring grovel area. The contact reading om the roof of
the hut was reduced by 10% (after subtracting the generel background fran
the readings, this indicated appracimately 25% decontamination of the roof),
tut there was no noticeable reduction in contact readings on the floor of the
mt or on the washed-deow: gravel ares. While this experiment cannct be
regarded as conclusive, it suggests that ome should not be optimistic about
the effect of future reins. It should be noted: that Enfiwetok itoll experience
on this subject is conflicting. During Operation Greenhouse, the heavy rains
fast prior to George Shot had little effect on the Dog Shot fali-cat, Ut the
reins that fallowdd scon after the departure of the Task Force appear te have
been fairly effective. However, even if the experience had been consisteat,
the terrain surfaces at Rengelap snd Eniwetok are so different that it would
be umeafe to draw sonelusicns.
Y% was evidentthat-dixy attempt at artificial decontamination wold be
diffienlt and very expensive relative to the cost of supporting the population
elsewhere until redicactive decay has reduced the rediatiom to an acceptable
level. Decontamination opsrations of the type used on Mniwetok Atoll (bulldosing and grading) would not be applicable because of the total destructim
of all vegetation and severe domege to the thin top-seil in the area covered.
Any reasonable non-destructive decontamination effort would have to be a
mammal job.