Frank Cluff 2 it was concluded that some radiation exposure could be avoided through removal of contsminated scrap metal such that it would be uneveailable to native collectors. Objectives - Following the August 1°63 trip to Bikini, a report on the visit was prevered by ADC staff containing en ettechment addressine the guestion of purpose and objective tor screp removal at Bikini Atcll. Recoumenéstions 1 throuzh 4 of this statement, known as Attechment 6 to that trio report, cprear to be a proper essesament of wheat is needed. This Attachment 6 is provided for your use. Sersp Disposal « If cost, time, and man-powcer were unlimited, disposal oi: all scrap metal containing any induced radioactivity in the very deep ocean oviside the reer would more certainly make the scrap un» evaileble to the returning natives. number of fectors to be considered: The location of chenanels in the reef throuch which boats loaded with sorap must pass is such thet disposs1 outside the reef for seraup Locvtions. in the northern portion of the atoll will involve & 25 to 70 mile reund trio. channels. - ne) WE 2hes wit ec 1. : f More realistically there ere a Currents may be very stroaz in these Except for a trgece quantity, the redionuclide in the conteminated metal serap is “Co with a half-life or about five years. This may be compared with the 30 year halfelife of 13%Cs which is a major component of soil redloactivity of the near test islands. The scrap contaminant will deczy through cix half-life pertods reaching about 1% of its 1967 vaive while the 157cs in soil of the near test islancs is being reduced to 50% of its 1967 level. a 3. Disposal of metal debris, which will sink to the bottom, in water 150 to 200 feet deep inside or outside the lazoon will make the scrap uneveaileble to the natives. Such material should not be recoverable without use of special equipment at these depths. The lagoon and ocean floors in the area of tcst locations already contein a total quantity of scrap expected to be in excess of that found on land. In fact, the added quantity from the land areas would probably be a very email fraction of this total.