The development of ionic methods for the determination of corrosive products in the highly radioactive Homogeneous Reactor (HR) fuels has been of major interest in the work of the Ionic Analyses Laboratory. Methods for the spectrophotometric determination of aluminum and for the polarographic determination of iron in HR fuels have been developed. The polarographic determination of molybdenum in uranyl sulfate solutions was studied. A polarographic method for the determination of zinc was developed. A fluorometric method for the determination of microgram amounts of fluoride was studied. Three organic reagents were investigated as precipitants for microgram quantities of zirconium in HR fuel. The automatic photometric titration technique was applied to the determination of thorium and of sulfate. A method was developed for the ion-exchange separation and potentiometric titration of cobalt. The ultraviolet absorption spectra of technetium and rhenium were studied.

Calculated data and graphs describing the effects of batch thermal-neutron irradiation of thorium, the usual method of operation of heterogeneous reactors, are presented. The buildup and decay of U233, Pa233, other heavy isotopes, and fission products are considered on the basis of best available cross-section and fission-yield data. The effects of these irradiation products on the Thorex chemical separation process are indicated briefly.