Radioactivity Release from Radionuclide Power Sources. III. Release from Plutonium Metal to Seawater

摘要

Plutonium metal reacts completely with natural seawater to produce solid reaction products, believed to be plutonium oxide and/or hydroxide, and a gaseous product whose major component is hydrogen. The mole ratio of plutonium metal reacted to hydrogen evolved is unity. The mixture resulting from the reaction of plutonium metal with seawater contains a non-uniform distribution of solids, and ionic and complexed species. In order to reproducibly sample this heterogeneous misture an experimentally determined sampling procedure must be followed which produces uniform results. The maximum rate at which plutonium solid reaction products enter into 'solution' in seawater is very slow, approximately 1.5 to 2 microgramx per day per 50-70 mg of solids in seawater. The effect of individual complexing anions on the solubility of the Pu solids was found to be additive. The equilibrium (or maximum) concentration of dissolved Pu in three samples of natural seawater was found to be 67 microgram/1. For seawater samples taken at different localities or at different times of the year, deviations from this value can be expected due to differences in the concentrations of complexing anions present. (Author)