Title: Phase equilibria and melting point data for advanced fuel systems

Fuels for advanced high performance aircraft engines will approach and traverse the critical region; therefore, the unique properties of supercritical fluid solvents on solubilities and reaction rates are applicable here. In the past years the authors have developed models for the prediction of various thermodynamic properties of compounds which are representative of fuel components and they have studied several reactions in supercritical fluids. The reactions studied in the past three years represent both fuel model reactions and reactions which will provide an increased understanding of molecular level events in SCF reaction mixtures, such as local composition effects in ternary systems.

Studies of the interactions of IFR fuel alloys with stainless steel cladding materials have shown evidence for segregation of metallic alloy components at the fuel-cladding interface. The phenomenon seems to be related to the availability of nitrogen and other reactive elements. For the interpretation of surface segregation results it will be necessary to establish (1) the composition of the phases formed in the ternary alloys under the action of nitrogen, (2) diffusion characteristics of various components in these phases and those of nitrogen itself, and (3) activity gradients established in the component metals providing driving forces for material migration. Inmore » this technical memorandum we present a literature survey and evaluation of the binary and ternary systems formed among uranium, plutonium, zirconium, and nitrogen. Both the phase diagram data and available thermodynamics are included. The following systems were surveyed: U-N, Pu-N, Zr-N, U-Pu, U-Zr, Pu-Zr, U-Pu-Zr, U-Pu-N, U-Zr-N, and Pu-Zr-N.« less

Results are reported from an analysis of data on thermal effluents emitted from the natural draft cooling tower of a fossil-fuel power plant located in the coastal region of Maryland. Data are included on the visible plume as recorded photographically, condensation droplet size distribution, ground-level sea salt concentrations, and plume dispersion and drift in relation to wind velocity and other meteorological conditions as influenced by seasonal changes.