OPERATIONS PLAN LLL RADIOECOLOGY AND DOSE ASSESSMENT PROGRAM AT ENEWETAK ATOLL November 30 through December 14, 1977 BACKGROUND AND PURPOSE Lawrence Livermore Laboratory (LLL) has established a program in conjunction with the Department of Energy to investigate the measurements of radionuclides in the soil, water and biota, radio- ecological transport modeling and dose evaluation in the Marshall Isiands. These investigations are to fulfill the high priority needs for effective rehabilitation of Enewetak Atoll. The Enewetak Survey of 1972 which resulted in the NVO-140 report (Enewetak Radiological Survey) provides a description of the radiological status of Enewetak Atoll at one point in time for the purpose of evaluating constraints on rehabilitation and cleanup plan development. Resettlement requires additional studies over a longer time frame to assess 1) leaching rates of radionuclides from the soil and vegetation; 2) radionuclide availability to plants; 3) percolation rates and radionuclide content of soil water and ¢) general radionuclide cycling phenomena in the environment. If. DESCRIPTION OF MISSION A. LLL will conduct followup activities at Enewetak involving: i. Plant some new crops including squash and watermelon. 2. Harvest mature crops and prepare samples for shipment to California. 3. Moisture measurement work. 4. Fertilize crops and weed plots. 5. Sample soil and vegetation from test plots. 6. Continue ecological experiments designed to evaluate the cycling mechanism for Csl137, Sr 90, and Pu in the atoll ecosystem. 7. Interact with H&N individual assigned to support LLL Garden Project 25% of his time to ensure a complete understanding of necessary requirements for sample collection, crop maintenance, and data reporting and sample shipping procédures.