already
deposited in the crater sediments, but it also again sent a
surge of contaminated water over adjacent islands including Janet.
1956,
islands during the test years.
In
the Redwing series began with a tower detonation on Yvonne and
included two additional cratering events, LaCross and Seminole.
eventual fate of the radfoactive debris, e.g., location and quantity of
LaCross
was a 39,5-kt device detonated on an earth-filled causeway built on the
reef off the north end of Yvonne.
Unfortunately, none of the radiological
safety reports during these operations provided details to determine the
Seminole, detonated on the island of
the disposal (Ne73).
From this brief summary, we can assume safely that the transuranic
elements were introduced to the aquatic environment not only as
Irene, was first placed in a ]15-ft diameter tank that was itself then
complicated carbonate particles fused or condensed with other material
placed in a 50-ft-diameter tank filled with water before it was fired.
from the environment or with devices and associated structures, but also
During 1958, the final year of testing at Enewetak, 22 tests of various
as soluble and particulate species of transuranium oxide.
types were held at different Atoll locations during an 82-da period,
Despite the complexities in the formation processes, much of the
The series opened with a 86000-ft ballon shot over the Atoll on 28
behavior of the transuranics is similar to those determined from
April.
investigations of fallout and other aquatic pathways.
On 5S May, a 18~-kt device produced Cactus Crater on the northwest
end of Yvonne and west of LaCross Crater.
During May 11 to 12, one of
The results from
the Atoll studies therefore have great value in predicting transuranic
the three tests was the Koa event, a 1,37-Mt nuclear device housed in a
behavior and fate on a global aquatic scale,
tank of water and detonated on the east end of the Gene-Helen island
complex,
June 8,
A sizable crater was produced, connected with Mike Crater.
the Umbrella device was detonated on the floor of the lagoon,
Twenty days later, the 8.9-Mt Oak device was fired on a barge 4 mi
southwest of Alice off the edge of the reef.
that breached to the lagoon,
The test left a crater
The Quince event on Yvonne Island failed
On
TRANSURANICS TDENTIFIND AT THE PACITIC TEST STTE ALUILS SINCE 1972
Neptunium
Concentrations of
237
Np in several 1972 samples of unfiltered
lagoon and crater water from Enewetak were determined by mass
spectrometry (No74),
The average concentration in six samples from the
to produce a fission yield so that the plutonium within the device was
lagoon was 0.058 + 0.013 fCi/i.
dispersed by high explosive.
averaged 0.45 + 0.22 fCi/l.
Subsequently another nuclear device was
Water samples from Mike and Koa craters
Outside of the lagoon and to the east of the
successfully detonated over the same area that undoubtedly further
Atoll, concentrations in water samples from the open oceun surface
dispersed the nonnuclear~generated plutonium,
averaged 0.013 + 0.003 fCi/l.
In addition to the
nuclear tests, radionuclides were dispersed by plowing on many of the
This comparison shows, as de results
for
all other transuranics, that Atoll] sources contribute the major fraction
DoF ARCBIVES