BIKINI ISLAND
The island of Sikini is the largest in the atoll, having an area of
about 0.6 square miles and has traditionally been the "home island”
of the Bikinians.
the ocean.
Individual land rights extend from the lagoon to
It is anticipated that the villaace will be rebuilt along
the lagoon shore with community buildings heinc jocated about midway
along the length.
The istand was prepared for agricultural redevelopment by cutting parallel
strips through the vegetation along the length of the island.
cut.on 56-foot centers, were approximately 20 feet wide.
The strips,
The vegetative
cover was knocked down and left in place to provide additional organic
matter for the soil.
The strips were surveyed and background gamma
radiation levels recorded at 250-foot intervals along their lenath.
Figure 2 illustrates the background variation by depicting the range
and average of radiation measurements for areas consisting of approximately four strips.
Although a large amount of debris was found on Bikini (from testing program and World War II) with one exception, none was radioactive.
One
pile of roofing saper scraps contaminated primarily with 137Cs was
located northwest of center on the lagoon side of the island.
This
material, which snowed a contact reading of approximately 200 uR/hr,
was loaded into 55-gallon drums and disposed of in the ocean south
of Eneu.
The measured exposure rates were 10 uR/hr or tess along the beaches,
and ranged from 20-120 yR/hr inland.
Soil samples taken at three
locations having measured backgrounds of 20, 70, and 100 ;:R/hr showed
137Cs and 69Co to be the major gamma enitting contaminants.
These
were present in Cs/Co ratios of approximately 25/1, 50/1, and 30/1]
respectively for the three samples, and thus the projected exposure
rate decrease will very closely approximate the decay of !37C€s.
In
addition, 9°Sr was present in amounts ranging from 10-50% of the 137Cs
concentrations.
80th !37Cs and 99Sr are very significant contributors
to the potential internal exposure which may result from eating locally
grown food items.
Unless indicated as a Contact measurement all
were taken at 3 feet.
7
WD
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exposure rate measurements