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Equotions predicting the effect of various types of equilibrium chemical reactions on the liquid-phase moss tronsfer coefficient have been derived. In each case the reacting species were assumed to be present in equilibrium concentmtions at all points along the diffusion path. Equotions were derived for both the film and surfoce-renewal theories of simple mass transfer in conjunction with these equilibrium reactions.The well-known Hatto equation for the mpid second-order irreversible reaction wos shown to be o limiting case of the general equilibrium reoction A + B + €.The colculoted moss tronsfer coefficients were found to be functions of the concentrotion driving force and the overage concentrotion level over the diffusion path 0s well os of the magnitude of the equilibrium constant ond the diffusivities of the reacting species.

The vapor pressures of the fullerenes C60 and C70 have been measured over the temperature range 400–600 °C by the Knudsen-effusion thermogravimetric technique. For C60, a heat of sublimation of 38±1 kcal/mol is obtained, and the value for C70 is 45±1 kcal/mol. The vapor pressure of C60 ranges from 1.8×10−5 and 1.4×10−2 Torr and that of C70 is between 1.4×10−5 and 8.7×10−3 Torr over the temperature range investigated. At 500 °C, the vapor pressure of C60 is about 1035 that of graphite. The entropy of vaporization of C60 obeys Trouton’s rule.

The important new developments in nuclear fuels and their problems are reviewed and compared with the status of present light-water reactor fuels. The limitations of these fuels and the reactors they power are reviewed with respect to important recent concerns, namely provision of outlet coolant temperatures high enough for use in H 2 production, destruction of plutonium to eliminate proliferation concerns, and burning of the minor actinides to reduce the waste repository heat load and long-term radiation hazard. In addition to current oxide-based fuel-rod designs, the hydride fuel with liquid metal thermal bonding of the fuel-cladding gap is covered. Finally, two of the most promising Generation IV reactor concepts, the Very High Temperature Reactor and the Sodium Fast Reactor, and the accompanying reprocessing technologies, aqueous-based UREX and pyrometallurgical, are summarized. In all of the topics covered, the thermodynamics involved in the material's behavior under irradiation and in the reprocessing schemes are emphasized.

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Reaction of molecular oxygen as a modulated molecular beam with the basal plane of pyrolytic graphite is investigated. The graphite surface participates in the reaction in an unusual fashion. Oxidation tends to create a highly reactive surface while thermal annealing tends to deactivate the surface. The imbalance of these two competing processes results in slow changes in surface reactivity during the course of an experiment, which is manifest as hysteresis in the rate of CO production. The surface chemical reaction occurs on a much smaller time scale than the processes responsible for hysteresis. The data indicate that a two-branch, two-site mechanism explains both the hysteresis and the surface chemistry. Surface migration of adsorbed oxygen is shown to be a step in the production of CO. Carbon dioxide is barely detectible; its production rate is two orders of magnitude smaller than that of carbon monoxide at all temperatures.

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