Cesar
the lack of any top soil or other loose ground cover, and the sweeping
effect of the tide - the crater was open to the ocean side of the reef,
Scrap metal (contact readings)
Large quantities of activated scrap metal were found near the SGZ's,
probably constituting the major radiological hazard on Engibe.
maximum reading observed on scrap metal was 12 mR/hour.
The
This reading
was obtained from a large twisted I-beam wrapped around a metal collimator located on the northwest end of the island, just north of the large
bunker.
Alpha contamination
No surface alpha activity was detected on Engibe.
B.
Runit (YVONNE)
General Description
Runit is a long slender island situated on the eastern side of the atoll.
Ruuit possessed somewhat i1ess vegetative cover tnan sngibe, thus maxing
location and identification of SGZ's easier.
Travel on the island was
done mostly on the main road running the length of the island.
A survey
of Runit resulted in measured exposure rates ranging from a few uR/hour
to 1 mR/hour.
Scrap metal with contact gamma readings up to 35 mR/hour
was observed,
Alpha contamination in soil and in vegetation was detected
near the FIG Event site.
Count rates up to 3000 cpm (measured with a
PAC-1S) in wet soil were observed.
Exposure Rate Readings
One day was allotted to the radiation survey of Runit, thus allowing only
enough time to survey the northern half of the island.
Measured exposure
rates observed in the middle portion of the island averaged 15 uR/hour.
These readings persisted to within about 300 feet of the CACTUS crater lip.
A survey along a transect across the island through the ZEBRA Event site
indicated exposure rates ranging from 4 to 8 uR/hour.
Readings along a
transect across the island through the FIG Event site ranged from 1 to 6
uR/hour.
The highest measured exposure rates on the entire atoll (1 mR/hr)
occurred on top of the crater lip located at the southern end of the CACTUS