With the increasing research on advanced reactors, molten salt reactors have been recognized for their potential. As with any advanced reactor concept, each component and material must be thoroughly investigated before any reactors of that type are created. One of the most pressing issues in MSR research is that of the salts themselves. Though there are a multitude of salts to choose from when designing such a reactor, many of these salts lack the extensive research required to fully understand them. Across the decades there have been many studies that have investigated select molten salts, but there are a few problems with many of those studies. Those problems are the following: prior papers use obsolete and less reliable methods for their measurements, the papers don't investigate the salts across a wide enough range of temperatures nor at varying compositions, and finally many of the salts that are seen as candidates today were not given as much attention when molten salt reactors were first conceptualized which has resulted in a lack of research on them. Indeed, the research into these salts is lacking in many ways. This study seeks to investigate a collection of promising coolant salts in depth with acknowledgment to those past studies. LiF-NaF-KF (46.5-11.5-42.0 mol%) will be used as a calibration standard and for the purpose of verifying our methodology. Specifically, FLiNaK was used in the development of volume-height curves as calibration for density measurements. NaOH-KOH of four different compositions ( 0.5-0.5mol%, 0.55-0.45mol%, 0.6-0.4mol%, and 0.65-0.35 mol%) will be evaluated for their densities and heat capacities. And finally, BeF2-NaF(43-57mol%) will be evaluated within the question of if the properties are desirable enough that the dangers posed by beryllium are an acceptable risk. BeF2-NaF will have melting point, heat capacity, density, and vapor pressure measurements performed. Additionally, extensive impurity analysis and removal (via an HF gas system) was done to our BeF2-NaF samples. The melting point and heat capacity were evaluated using dynamic scanning calorimetry (DSC), the vapor pressure was evaluated using thermogravimetric analysis (TGA), and the density was measured using a system similar to the Arrhenius method that measures height. / Master of Science / Decades have passed since the discussion of nuclear energy began. Although great progress has been made in the field, the nuclear reactors in use today consist mainly of boiling water reactors (BWRs) or pressurized water reactors (PWRs). As reliable as these reactors have become, one can no longer ignore the fact that there is a multitude of other options for how a reactor can be built and operated.
Options that provide greater safety and more energy output. Many reactor concepts of the past were discounted for the extensive research that would be required to make use of them. However, as time has passed and technology has improved, that research has become more and more possible. Many advanced reactors are the result of that attention to the reactor concepts and materials of the past that couldn't be given the attention that they deserve until now. Molten salt reactors (MSRs) are one of those promising concepts. However, before they can be built every part of the reactor, from the structure to the materials, must be entirely understood. One of the most pressing issues in MSR research is the properties of the salts in consideration for use. Though there are a multitude of salts to choose from when designing such a reactor, many of these salts lack the extensive research required to fully understand them. Across the decades there have been many studies that have investigated select molten salts, but there are a few problems with many of those studies. Those problems are the following: the papers are so old that the methods that were used are now obsolete, the papers don't investigate the salts across a wide enough range of temperatures nor at varying compositions, and finally many of the salts that are seen as candidates today were not given as much attention when molten salt reactors were first conceptualized which has resulted in a lack of research on them. Indeed, the research into these salts is lacking in many ways. This study seeks to investigate a collection of promising coolant salts in depth with acknowledgment to those past studies. LiF-NaF-KF will be used as a calibration standard and for the purpose of verifying our methodology. A multitude of different compositions of NaOH-KOH will be evaluated for their densities and heat capacities. And finally, BeF2-NaF will be evaluated within the question of if the properties are desirable enough that the dangers posed by beryllium are an acceptable risk. BeF2-NaF will have melting point, heat capacity, density, and vapor pressure measurements performed. Additionally, extensive impurity analysis and removal was done to our BeF2-NaF samples.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/120685 |
| Date | 23 July 2024 |
| Creators | Ridder, Cathleen Elise |
| Contributors | Mechanical Engineering, Zhang, Jinsuo, Haghighat, Alireza, Leong, Amanda Sue Wen |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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