Two new positron active isotopes, B{sup 8} and Na{sup 20}, have been found to decay to excited states of Be{sup 8} and Ne{sup 20}, which in turn decay 'instantaneously' by alpha emission. Their half-lives are 0.65 {+-} 0.1 sec. and 1/4 sec. respectively. N{sup 12} is also found to have a low energy positron group which leads to an {alpha}-unstable excited state in C{sup 12}. The masses of B{sup 8} and Na{sup 20} are 8.027 and 20.015 respectively. B{sup 8} decays by a 13.7 {+-} 0.3 Mev positron, through the same excited state of Be{sup 8} as does Li{sup 8}. Estimates of the energies of the excited state in C{sup 12} and Ne{sup 20} are made.

A method has been adapted from ion exchange studies for removal of the fission products, Cs-137, Sr-90, and the rare earths for both untreated urine samples and the supernates from the precipitation steps in the TTA procedure for plutonium. Because of the excessive amount of eluant necessary to separate the fission products and the resulting time required to run a separation, a method was developed to remove the Sr-Y, Ce and Pr by chemical means and Cs from the raffinate of this extraction by ion exchange. It should be noted that Cs is easily separated from Pu in the separations plant, and that is presence as a contaminate in the outer areas is not as probable as the other long-lived fission products. This fact has been born out in three years of analyzing contaminated samples from the 200 Area by the H.I. Development Divisions.