Once-through nuclear fuel cycles leave thousands of metric tons of spent nuclear waste to be disposed of -approximately 80,000 tons in the US alone. The enduring proposal for disposal are geological repositories, deep facilities that store waste in crystalline rock or clay where they can safely decay without escaping into the biosphere. To ensure this, engineered barrier systems encapsulate the waste container, forming an additional boundary between waste and the biosphere. The time scale for disposal is ~1M years, with the first 100,000 years being the most critical. My work uses x-ray spectroscopy to characterize different concretes proposed for use in barrier systems to identify the best candidates for long-term disposal.
Advisor: Gerald Siedler – Material Science and Engineering