[en] Distribution coefficients were determined for sorption--desorption of radionuclides between each of three different types of tuff from drill hole J-13 at the Nevada Test Site and water from that well. The measurements were performed under atmospheric conditions at 22⁰C and 70⁰C. Sorption ratios vary greatly with lithologic variety of tuff. A tuff high in zeolite minerals has high sorption ratios (in decreasing order) for Eu, Ba, Cs, and Am and intermediate ratios for Sr and Pu. A tuff high in glass shows very high ratios for Ba, Sr, and Cs, intermediate values for Am and Pu, and low values for Ce and Eu. A devitrified tuff similar mineralogically to a microgranite exhibits intermediate values for Ba, Cs, Am, and Pu and low values for Eu, Ce, and Sr. Values for Ru are low, and those for Mo, Sb, and I are very low or zero for the three types. 34 figures, 32 tables