The radiation hazards associated with recycled nuclear reactor fuels will greatly complicate the handling and refabrication of these fuels. This problem is most serious with U-233 and plutonium fuels where the presence of U-232 and the heavier isotopes of plutonium contribute energetic alpha, gamma, and neutron radiations at levels many times that from isotopically pure U-233 and Pu-239. This report summarizes present knowledge of the radiation hazards associated with recycled fuel and the additional data needed to make a thorough evaluation of these hazards.

A method was developed for the determination of osmium by measuring the absorbancy of osmium tetroxide in CHCl3. The osmium is first oxidized to the octavalent state and the osmium tetroxide which is formed is extracted selectively with CHCl3. The ultraviolet absorption spectrum of OsO4 in CHCl3 has a series of absorption bands with peak absorbancies at 282. 289, 297, 304 and 312 mu, and molar absorbancy indices of 1870, 1760, 1640, 1400 and 1000, respectively. For each wavelength the optimum concentration range for the determination of osmium was evaluated by the method of Ringbom. Only chloride and octavalent ruthenium interfere in the determination. By this method, from 0.4, to 3 mg of cesium can be determined with a coefficient of variation of 3 per cent.