The results of a radiochemical study of fission and spallation products induced in U234, U235, and U/sup 236 and spallation products induced in U238 by deuterons of less than 24 Mev are presented. The (d, n) reactions are interpreted as the result of direct interactions between the deuteron and the target nuclei, while the (d, n) reactions are thought to be taking place primarily by compound-nucleus mechanisms. A method for predicting the peak values of the cross section for (d, xn) and (alpha, xn) reactions on uranium and plutonium isotopes is given for x = 2, 3, or 4. The peak-to-valley ratios of the fission-yield curves for U/sup 234, U235, U236, and U/ sup 238/ bombarded with deuterons of energies of about 23 Mev were studied, and no significant differences were found. Excitation functions for the (d, gamma) reactions of U234, U236, and U238 rise to a maximum of about a millibarn at a bombarding energy between 15 and 20 Mev. The results of these measurements are seen to be consistent with the excitation functions for (p, gamma) and (alpha, gamma) reactions. The 60minute neptunium activity which had previously been assigned to Np241 was identified as an isomer Np/sup 240/. Accompanying the decay of this Np24° are gamma rays of energies 1160, 1000, 915, 595, 565, 435, 245, 16O, and 85 kev. Np241 has now tentatively been found to have isomers with half lives of 16 minutes and 3.5 tours. A study of the decay properties of the new isotope Np241 and also of Np233 and Np234 are described. (auth).