,,. Dr. James L. Liverman -3- August 17, 1977 The Environmental Impact Statement indicates that 90s= and 137cs ~ the soil md the uptake by plants is the major problem which will limit the occupancy and utilization of certain islands of the Atoll. Certain soil amendments that have been shown to significantly decrease the uptake of these radionuclides may be useful for hastening the rehabilitation of the Atoll. B. Disposal of plutoni-contaminated the Cactus Crater soil and debris in In examining the question of disposal of contaminated soil and debris, the reviewers considered potential human health effects, future maintenance and monitoring requirements, retrievability, potential restrictions on access to Runit Island, implications and risk of reopening the Environmental Impact Statement, costs, quantities of debris, and engineering problems. Weighed against these considerations the reviewers agreed that the planned emplacement of concreteencased plutonium-contaminated soil and debris in the Cactus Crater would not in itself impose unacceptable human health risks. me IrI12thOd cculd result in the gradual release of this plutonium to the marine environment; this would be in addition to the 1500 Ci already in the lagoon sediment. Bowever, for the worst case in which 10 Ci Pu is added to the Crater below the water level, the local lagoon water plutonium concentration would not fncrease more than by a factor of two. This could lead to an increased dose of a few mrem per year to a person who obtained all of his food from the local marine environment. Several alternate disposal schemes, while not significantly influencing the health risk prospects, might be preferable. While it may be inadvisable to change disposal plans at this late date, the reviewers believe you should be aware of the possible advantages of other methods. o