Thermal Modeling of a Salt Repository for Nuclear Waste
Open Access
- Author:
- Borza, Gregory Michael
- Area of Honors:
- Nuclear Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Dr. Massimiliano Fratoni, Thesis Supervisor
Seungjin Kim, Thesis Honors Advisor - Keywords:
- Nuclear
Repository
Nuclear Waste
Spent Nuclear Fuel
Salt - Abstract:
- Spent nuclear fuel can no longer be permanently stored at the Yucca Mountain site; therefore, alternative options, salt being one of them, are being explored. Salt has many favorable qualities that make it an excellent candidate for a long-term repository. The most pertinent to this study is its relatively high maximum allowable temperature (200°C), which decreases the size of the repository. Two different finite element simulation codes were implemented to analyze the thermal response of the salt repository: Diablo and Comsol. Diablo was used to explore how crushed salt porosity, package spacing, and spent fuel interim storage time affect the maximum temperature of the salt. The results indicated that porosity can play a noteworthy role on salt temperatures and that increasing interim storage time can significantly decrease the required repository size. The Comsol model, on the other hand, investigates the geological footprint of the repository under conservative conditions. The optimum number of fuel assemblies in each waste package depends on the fuel’s interim storage time. For small storage times (~10 years) a smaller waste package is optimal (four assemblies); however, as storage time increases the ideal package size also increases. For a 50 year interim storage time it was found that a 12 assembly waste package is optimal.