TABLE 6-5. COMPARISONS OF WATER CRAFT SOIL HAULING CAPABILITY LARC-60 Crew Load, cubie yards LCM-8 8 3 10 LCM-8 BULK HAUL* 3 10 40 29 41 LCU TUG with 2 Causeway sections 8 6 60 40 38 80 29 93 Load time, minutes Travel time, loaded, minutes** 12 a3 15 4] Travel time, empty, minutes 48 4] 17 70 36 30 41 47 130 13 114 11.4 176 4.4 173 2.9 228 o.7 Of fload/reload Total time, minutes Minutes per cubie yard 17 63 *Four previously-loaded trucks dumped into an LCM-8. **Travel from Tilda to Yvonne. 6.7 PLOWING PHILOSOPHY AND EXPERIMENT (by Paul Dunaway, DOE) Plowing or other methods of mixing soil bearing radioactive contamination with relatively uncontaminated soil have been used in the past at several places in the U.S. and elsewhere to reduce radioactivity concentrations per unit of weight or volume of soil (Wallace and Romney, 1975). Plowing is essentially a dilution technique. The Environmental Protection Agency (EPA) stated, "For soils with transuranium element concentrations no higher than about 10-100 times the guidance recommendations, remedial actions to bring such areas into compliance would generally involve only plowing or surface removal ..." (EPA, 1977). A sereening level of 0.2 »Ci/m% of transuranic At concentrations lower than that level EPA would not exceed guidance recommendations (1 mrad/yr to pulmonary lung or 3 mrad/yr to bone). The Bair Committee also mentioned the possibility of plowing contaminated soil at Enewetak Atoll. The Committee did not make any recommendations as to the advisability of such an action but approved of the concept of conducting a plowing experiment (Bair, 4/1978) and later evaluating | elements in the top em of soil was specified by EPA. was of the opinion that potential exposure to man from uptake (inhalation or ingestion) ordinarily radionuclide uptake by plants in plowed versus unplowed soil (Bair, 10/1978). In the early part of 1978, the Defense Nuclear Agency (DN A) began to formulate plans to conduct a plowing experiment at Enewetak so that they might employ the technique should it be reeommended later. Accordingly, DOE assisted the DNA to perform the experiment but withheld any Dr. R. C. Jones, University of Hawaii, an expert on Pacifie Ocean Atoll soils, and Dr. C. W. Francis, Oak Ridge National Laboratory, an expert on radionuclide movement in soils, were retained to advise on the experiment. ERSP personnel at Enewetak were also detailed to assist with the experiment. IMP and radiochemical assets were made rq recommendations that the experiment be done. available. A large moldboard plow (Post Brothers, Model PB 142RH), 1.27 m in height (share plus moldboard), was shipped from the Nevada Test Site (NTS) where the plow had been stored in the event that plowing would be recommended eventually for several contaminated areas at NTS. Preliminary plans for the plowing experiment were developed during a planning meeting at Enewetak on 1l May 1978, with DNA, the ERSP on-site Manager, and ERSP contractor personnel. Prior to this meeting, ERSP had already started work on selection of experimental areas and acquisition of Most of the requisite information about the experiment and results are contained in Tech Notes 9.0 and 9.1, in one unpublished report (Jones and Francis, 1978), and in one published report (Denham, et al, 1980). However, for continuity in this report, the following summary is provided. 171 wes preliminary data on soil profile structure and radionuclide data (Tech Note 9.0).