Franklin G. King

Effective diffusivity of carbon dioxide and iodine through G tunnel tuff

The Topopah Spring Member of the Paintbrush Tuff in Yucca Mountain Nevada is a prime candidate for the site of the first national high level radioactive waste repository. Spent fuel from power reactors is currently considered to be the most significant commercial high level nuclear waste form. The effective diffusivity of carbon dioxide and iodine through G tunnel tuff were determined using a steady-state method and an unsteady-state method respectively. Results show that the effective diffusivity of carbon dioxide and iodine through dry tuff increased with temperature. The effective diffusivity of carbon dioxide decreased as the moisture content of the G tunnel tuff increased. An empirical correlation was obtained to estimate the effective diffusivity of carbon dioxide as a function temperature and the percent saturation. Specific surface area and pore volume of tuff was determined using a mercury porosimeter. A scanning electron microscope was utilized to further characterize the porous structure of the tuff samples.

Enhancement of Equilibriumshift in Dehydrogenation Reactions Using a Novel Membrane Reactor

Electroless deposition of palladium thin-films on a surface of microporous ceramic substrate has been used to develop a new class of perm-selective inorganic membrane. In our previous two reports, we presented mathematical models to describe transport of hydrogen the palladium-ceramic composite membrane in single-stage permeation cell in cocurrent and countercurrent flow configurations. Analysis shows that the model equations have a singular point. In this report, a method is described how to avoid the singular point in order to solve the model equations numerically. To show the usefulness of the new method, a single-stage gas permeation for a three component system, without chemical reaction under cocurrent flow configuration has been used as an example.

Enhancement of Equilibrium Shift in Dehydrogenation Reactions Using a Novel Membrane Reactor Semi-Annual Report: September 1996-February 1997

A mathematical model is developed to describe the permeation of hydrogen through thin-film palladium ceramic composite membrane in cocurrent flow configuration. Numerical simulation results show that the model under predicts reject composition and over predicts the product purity. These results suggest that the gas phase mass transfer resistance could be important. The difference between the predicted and actual hydrogen composition is less than 12%. Thus the model appears to be adequate for predicting the membrane module performance.