coordinates, depth, and gamma activity reading.
Each sample was prepared for counting by
removing the moisture through a vacuum filter and transferring the soil to a standard petri dish.
Each sample was weighed on a gram scale and the weight and EIC sample number were recorded. All
samples were scanned using the IMP gamma detector and the data transferred to DRI for analysis.
Samples were saved for archiving or disposal as directed by DOE/ERSP.
Exeavation and Bottom Sediment Sampling. Excavation of the Aomon Crypt was started by JTG on
15 January 1979 using a clamshell. Operational samples of the dirt pile and bottom sediments were
collected as requested by DOE/ERSP. The EIC sampling crews were staged out of the Ursula camp
until 26 January 1979, and thereafter sampling missions were staged from the RADLAB at
Enewetak. On 5 April 1979 a complete set of bottom sediment samples was collected from the pond
created by the excavation using a sediment sampler borrowed from MPRL. A military pontoon
footbridge was used to provide a walkway for sampling personnel. Position reference was provided
by grid marks on the sheetpile or stakes located on the crypt perimeter. Bottom sediments were
prepared by vacuum filtration and aliquoted into petri dishes for gamma scanning by the IMP at the
EG&G facility on Ursula, or returned to Enewetak for counting at the RADLAB. Water samples
were also collected and the suspended material filtered out. The bottom sediment material
consisted of a gray and black claydike material which contained measurable gamma activity.
Additional samples of the bottom sediments were collected during the final cleaning of the crypt
bottom with a clamshell at the end of May 1979.
Post Backfill Sampling.
A barrel-type impact core sampling tool mounted on a truck was used to
sample 26 locations to 120em in the Aomon Crypt area after it had been backfilled with
radiologically clean beach sand. Samples were returned to the RADLAB at Enewetak for
processing. The Aomon Crypt project was completed on 28 July 1979 with final core sampling. All
Aomon Crypt certification samples were archived along with representative samples of the bottom
sediments.
4.2.4 Soil Archiving
The soil archiving program was initiated by DOE/ERSP to provide a library of samples that were
representative of the "as left" conditions of the Enewetak Islands at the end of the project. The
archived samples consist principally of surface soil taken in support of the transuranies program and
the FPDB samples. Future researchers may recheck the earlier data or may run new analyses with
more sophisticated procedures to check on elements for which analysis was not done during the
clean-up.
Samples were prepared in accord with DOE/ERSP Procedure 20 in Appendix A.
The preparation
started in late 1978, after discovering that the soil sample cans stored in the warehouse on the south
end of Enewetak were rapidly corroding due to the high moisture and salt content of the air. Mother
Nature, in the form of Typhoon Alice in January 1979, had a substantial influence in hastening the
archiving project by destroying the warehouse and about 5 percent of the stored soil samples. After
Sterilizing to meet Department of Agriculture importation requirements (DOA Permit S-2044),
samples were placed in Army Mil Van units, as shown in Figure 4-8, for shipment to the Nevada Test
Site. A total of 11,455 samples were shipped at the close of the project.
4.2.5 Soil Sample Data Base
A soil sample data base was compiled from data contained in field notes, RADLAB analysis sample
control records and final chemistry reports. See Section 4.3.5 for a discussion of this information
and procedures used during the Enewetak project.
RADLAB soil sample handling is described in
DOE/ERSP Procedure No. 8. All field sample notes and log books were kept by island and sent to
DOE/NV for archiving at the close of the project in 1980.
4.2.6 Additional Support Programs
In addition to the program support described above, Eberline provided support to the FRST, off-site
counting, and instrument repair and maintenance programs.
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