An integrated systems approach framework was developed that defines the performance of a near surface low-level radioactive waste disposal facility as a system of three components (or subsystems): the engineered component (cover systems and bottom liners); the properties of the waste (composition, waste form and waste package); and the site-specific environmental features (climate, geology, hydrology). US government radioactive waste disposal facility design and management were examined and compared using this approach. The waste component, historically not considered when calculating waste movement within the facility, was evaluated in greater detail by looking at corrosion of carbon steel boxes filled with waste and buried in a humid environment. The time to hydraulic failure from initial burial to development of corroded holes was calculated for four corrosion scenarios under a constant and a slowing corrosion case. Corrosion rates were estimated from several historical studies and related to the corrosivity and aeration profile of the soil. The scenarios were chosen to represent a range of possible conditions at current and future U.S. Department of Energy disposal facilities. A leachate model was then created that could show the amount of liquid leachate present in each waste package at the time of failure. This model was applied to three different infiltration situations based off of past, current, and proposed future installations of operational and interim cover systems over recently buried waste packages. It was found that for past practices of a 25-year operational period, the estimated amount of leachate within the waste zone over current practices was greater than 300 percent. In order to reduce leachate for future planned disposal facilities, it would be useful to install interim cover systems immediately after waste burial, and fill the waste packages with grout before disposal. For all disposal facilities, leachate movement from the waste zone into the vadose zone would be a good target for performance monitoring.
| Identifer | oai:union.ndltd.org:VANDERBILT/oai:VANDERBILTETD:etd-04142016-075127 |
| Date | 14 April 2016 |
| Creators | Rustick, Joseph Henry |
| Contributors | Dr. Michael T. Ryan, Dr. James H. Clarke, Dr. Steven L. Krahn, Dr. David S. Kosson, Dr. Craig H. Benson |
| Publisher | VANDERBILT |
| Source Sets | Vanderbilt University Theses |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.vanderbilt.edu/available/etd-04142016-075127/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Vanderbilt University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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