Nuclear Engineering Commons^™

A Sensor For Oxygen In A Potassium-Sodium Alloy, Michael George Pastis

Masters Theses

This project supports a research project to determine the configuration for heat exchanger welds in a space reactor. The reactor is a sodium-potassium (NaK) cooled reactor for use on future missions on the lunar surface or on Mars. Various types of welds in Type 316L stainless steel have been positioned in a furnace which is part of a NaK test loop. The specimens are bathed in circulating NaK at 600 degrees centigrade.

Since the oxygen concentration in the NaK is a major factor in corrosion of the weld specimens, it must be carefully monitored and controlled. However, few techniques are …

Simulations Of Ti-Y-O Nanoclusters In Ferritic Alloys, Natalie Browning Camilli

Masters Theses

Nanostructured ferritic alloys possess high strength and resistance to radiation effects due to the presence of nanoprecipitates. Though nanostructured ferritic alloys have desirable mechanical properties, the exact composition and structure of the nanoprecipitates is unknown; thus, atomistic simulations involving the formation of nanoclusters give insight as to their structure. This thesis focuses on the structure, formation and radiation stability of Ti-Y-O [titanium-yttrium-oxygen] nanoclusters in iron. The activation energies for diffusion and the diffusion coefficients of oxygen interstitial atoms in iron are determined. The binding energies of various combinations of oxygen interstitial atoms and iron vacancies are also tabulated. Thermodynamic formation …