August 1973 4Qo772 an : PLUTONTUM TN THF RIKINI WATFR SAMPLFS This is a preliminarv report on the plutonium isotopes in the Pikini water samples collected and nrocessed on the research vessel "Palumbo" from October 1972 - December 1972. The procedure followed for the water samples was as follows: About 100 - 400 liters of unfiltered water were acidified to pil 1 - 2 with Con-liC] in the steel settling towers 80" high. \v The water was stirred by a rising column of air hubbles. Spikes of Pu242 and Am243, along with 10 mg Fe/liter as a vo av chloride and 0.25 ml/liter of 0.3% Separan as a coagulant, ‘were added. The spikes contained 4.442 dpm of Pu 242 1.697 dpm Am243, ang The pH was raised to a valne of & - @ hy addition of ammonium hydroxide, the stirring continued for an additional 39 - 40 minutes and the precipitate was allowed to settle for two to six hours. Fach precipitate was removed thru a valve at the bottom of the settling tower and centrifuged to a final volume of 190 mi of floculant precipitate. The ferric hydroxide precipitate was dissolved in minimum amount of Con-HC1, warmed and centrifuged. Undissoived residue was treated with HNOz and HF to remove organic matter and silica. After repeated evaporation with HINOz, the residue was dissolved in a minimum amount of 8N JIC] and added to the original solution. In a few earlier samples, fuming perchloric acid was used, hut is now heing ahandoned 20039521 S vey’ 0867 ¥°