FIGURE 4-7. BALL MILL FOR FPDB PROGRAM SAMPLES After completing the 100-meter grid samples, the 50-meter samples were gamma scanned at Enewetak and all the 100-meter and 50-meter samples were prepared for archiving. The ball mill constructed for processing FPDB program samples is shown in Figure 4-7; up to 24 samples in 1-gallon eans could be processed simultaneously. The FPDB program, including the analyses of all 50-meter samples, was completed during the week of 7 July 1979. 4.2.3 Aomon Crypt Sampling Pre-Excavation Sampling and Coring. Initial test holes were excavated by JTG teams before September 1978 to test the soil sidewall stability. Holes were dug to depths of 5 feet in the area around the center monument. Soil and debris removed from the holes were monitored for radioactivity with a PG-2 (small FIDLER). Detectable readings were obtained from the visible traces of grey-colored clay silt found in the predominantly coral material. Metal debris removed from the hole near the monument had very high levels of Alam activity. A 5-meter by 5-meter grid system was established as a reference system for future sampling. A small drilling rig with a split-spoon sampler was brought in by JTG in November 1978 to map the extent of contamination in the crypt area. A plywood building for sample preparation was constructed on Tilda 50 meters east of the crypt, within the crypt hot line, to provide a semi-dry working facility during IMP gamma scanning of the core samples and to protect the sample preparation equipment. During the coring operation, starting 26 November 1978 and ending 13 January 1979, approximately 1,000 soil samples were collected from 125 grid locations and processed by IMP scanning. Each sample with a 240 am activity greater than 25 pCi/g of soil was sent to the RADLABto be dried and gamma seanned. Ten percent of all samples with activity levels less than 25 pCi/g were also sent to the RADLABto be processed as quality assurance samples. Using an 18-inch core shoe, core samples were taken at each 2-foot depth. The core shoe was seanned with a PG-2 detector for gamma activity and sample material was collected in a 1-gallon can. Samples were allowed to sit for a short time, then surface water was decanted before the can was sealed and moved to the sample preparation building. Cans were marked with the grid 12]