Radiation Shielding Concrete for Spent Nuclear Fuel Interim Dry Storage
| dc.contributor.advisor | Chidiac, Samir E | |
| dc.contributor.author | Elsamrah, Moamen G | |
| dc.contributor.department | Civil Engineering | en_US |
| dc.date.accessioned | 2021-08-23T19:29:35Z | |
| dc.date.available | 2021-08-23T19:29:35Z | |
| dc.date.issued | 2021 | |
| dc.description.abstract | The demand for nuclear energy, which is marketed as zero-emission clean energy and a secure source of electricity, is continuously rising globally. However, associated radioactive waste such as spent nuclear fuel (SNF) presents a serious health and waste management hurdle. Interim dry storage methods have emerged as a remedial measure for the nuclear industry. This includes the concrete-based dry storage cask which is the focus of this study. The evolution and design requirements of SNF dry storage casks and interim storage facilities were first reviewed, and the existing design and operation challenges were identified. Accordingly, four comprehensive studies were undertaken: 1) quantify the effects of minerals and other additives added to enhance radiation shielding concrete on the concrete physical and mechanical properties; 2) develop a user-friendly computational software, named MRCsC, for estimating fast neutron macroscopic removal cross-section, ΣR (in cm-1), for shielding materials; 3) investigate experimentally and analytically the effects of adding powder boron carbide on Portland cement hydration kinetics and concrete compressive strength and radiation shielding properties; 4) study analytically the effectiveness of aggregates such as barite and celestite on concrete radiation shielding properties, and model the feasibility of developed concrete mixes as an overpack in a sandwich-design storage cask using the software OpenMC. Overall, the results reveal that sandwich-design concrete cask meets all the requirements for SNF dry storage. The addition of powder boron carbide, up to 50% by weight of cement, delayed the cement initial setting time by approximately 6 h, yielded a 15% increase in cumulative heat of hydration and a 28% increase in concrete compressive strength after 3 days, and increased the thermal neutron absorption (Σabs) close to 62000%. Concrete mixes with barite and celestite, as coarse aggregates replacement, significantly improve concrete radiation shielding efficiency and feasibility of sandwich-design storage cask. The OpenMC model results revealed over 60% decrease in the total dose rate. | en_US |
| dc.description.degree | Doctor of Philosophy (PhD) | en_US |
| dc.description.degreetype | Thesis | en_US |
| dc.description.layabstract | The dire need for radioactive wastes disposal, especially spent nuclear fuel (SNF) being the most hazardous, has increased with the ever-increasing accumulated amount worldwide. This disposal must be safe, efficient, and long-term. Therefore, different techniques have been employed to provide secure storage for these harmful wastes. However, one technique has lately gained notable importance in the absence of a permanent repository until now; which is the interim dry storage technique. This technique guarantees secured long-term storage, with relatively low costs, for all kinds of radioactive wastes. Concrete, a reasonably cheap construction material, is one of the main components existing in multiple faces of interim dry storage. As a result, continuous research aims to develop concrete mixes with enhanced properties, especially radiation shielding properties. This would lead to a reduction in the needed thickness/area, simplifying the overall design requirements, and saving materials, thus decreasing the total costs. Accordingly, developing concrete mixes with improved properties, specifically radiation shielding properties, is the pivot of this research. | en_US |
| dc.identifier.uri | http://hdl.handle.net/11375/26803 | |
| dc.language.iso | en | en_US |
| dc.title | Radiation Shielding Concrete for Spent Nuclear Fuel Interim Dry Storage | en_US |
| dc.type | Thesis | en_US |