~y 286 RADIOLOGICAL CLEANUP OF ENEWETAK ATOLL excision areas. The layout was verified by the Officer in Charge of the USAE unit scheduled to accomplish the excision. Theinitial survey, whicy i had to be completed before the DOE IMP survey operation coulg be 4 carried out, consisted of establishing a 25- or 50-meter north-sourp, i points. Each island had several reference points which had been tied into the worldwide coordinate system. A three- to four-man survey team, With a FRST member asradiological escort, was required. When a soil lift areg wasidentified, surveyors prepared a sketch of the area, brought elevation orthogonal grid system which wastied into the island’s surveyreference and position reference stakes to nearby locations, and establisheq elevations over the excision area, generally using a 12-1/2- or 6-1/4-meter grid. The sketches of the area became the mapsforsoil excision. For the pilot soil removal project, the area around the Kickapoo test Gz was surveyed and staked by USAE surveyors to mark the perimeter of contamination which exceeded 40 pCi/g, as determined by thein sity system. BRUSH REMOVAL At the Kickapoo GZ area, another brush removal experiment was conducted using the equipment previously tested at Enjebi. The front loader and grader again proved unsatisfactory. Roots were left in place, and wheel churning caused an unacceptable amountof soil disturbance. The D8K dozer proved the mostsatisfactory equipmentfor soil removal at the Kickapoo area (Figure 6-4). Ground surveyors estimated thatless than 30 cubic yards of soil were moved with the roots to the windrows of brush using the dozer. Later, at the Yuma GZ area, improved procedures were developed for removing brush with the front loader (Figure 6-5). For small bushes or é i brush, the loader with four-in-one bucket was used in a push mode. By closing the bucket and pushing forward, keeping it about 6 inches above ground, small bushes and brush could be cleared rapidly with minimalsoil disturbance and little soil remaining in the vegetation pile. For larger bushes, the four-in-one bucket was lowered over the bush and firmly closed without cutting the bush. The bush was then lifted out of thesoil. With the sandy soil conditions present, virtually all the soil fell from the root system. Thereafter, the front loader was used for most brush removal operations. The uprooted vegetation was windrowed just outside the excision area. When it was reasonably dry, normally after the main work force had departed, it was doused with diesel fuel and burned in place. The ashes were screened by the IMP and, if found to be contaminated, were transported to Runit for entombment. If the ashes were not contaminated, they were left in place for soil enrichment. es ance