My research focuses on deliquescence behavior of salts and dusts inside
geologic repositories for nuclear waste, such as the potential high-level waste
repository planned by the Department of Energy at Yucca Mountain, Nevada.
Groundwater and dusts traveling through such a repository may come in contact
with waste canisters and drip shields. If the temperature of the repository is
high due to heat produced from radioactive decay, the water will evaporate,
leaving behind a mixture of salts and dusts of various compositions on the
waste packages.
The hypothesis being tested in this research is that as the heat dissipates
and humidity returns to the underground environment, salts in the mixture may
absorb water from the air, forming a concentrated brine solution. The humidity
at which the salts begin to absorb water to form this solution is called the
deliquescence relative humidity of the mixture. These solutions, depending on
chemical composition, are potentially corrosive to the waste canisters. If
canisters corrode, radionuclides can be released and become an environmental
contaminant, potentially entering the water table. This study examines possible
chemistries of such mixtures, based on studies of natural waters and dusts, and
to experimentally determine, where possible, the deliquescence points of the
mixtures using impedance-based methods. This information can be directly applied
to corrosion studies, canister life-expectancy studies, and environmental hazard
risk analysis.
