Future Pathways to U.S. Decarbonization Through Nuclear and Other Energy Systems

This thesis examines the hurdles involved in converting the U.S. energy system to one that emits little or no carbon dioxide into the atmosphere. The first part of this thesis looks at nuclear energy in the U.S., while the second part examines the pursuit of decarbonization through decentralized micro-grids.

The thesis begins by examining the possibility of a U.S. domestic market for factory-manufactured small modular nuclear reactors (SMRs) being developed through the use of hybrid water-energy systems. This work found that the use of the proposed hybrid system will not likely lead to the mass market needed to facilitate the mass manufacturing of SMRs. On the electricity side, these hybrid systems powered by SMRs are not cost competitive in the U.S. against similar low carbon technologies like natural gas equipped with carbon capture and sequestration (NGCCS). On the water side, I conclude that the need for water desalination over the next several decades in the U.S. will not be large enough to support the mass SMR market I was searching for. However, there might exist substantial markets in arid countries where natural gas prices exceed 12 $/mscf and where there is a strong desire to adopt nuclear power.

Chapter 3 investigates the perceptions of nuclear power as supported by existing theories on differing nuclear perspectives. Our survey participants held significantly less favorable views about nuclear energy if they cited Chernobyl and Fukushima as noteworthy events that shaped their perception. I found that Chernobyl has the most negative impact on participants, even for those who were not alive for the event. There was also a significant increase in negative views of nuclear energy in participants who would have been between the ages of 20 to 30 years old during Chernobyl, but these results do not extend to other events like Fukushima. The survey results also suggested that participants who are both non-white and non-male held significantly less favorable views compared to white males.

Chapter 4 examines the trade-offs between decentralization and decarbonization in microgrid planning. A trade-off curve is produced by using a previously developed mixed-integer program (DER-CAM) in a multiobjective programming framework. The results include a range of microgrid designs with different technology mixes or typologies. As the weight on greenhouse gas emissions increases the associated costs rise; at the design that minimizes emissions, the levelized cost of energy (LCOE) of the micro-grid rises to approximately 7x the current cost of electricity in southern California. Changes in natural gas (NG) prices do not change the micro-grid’s typology, but rather forces a quicker transition to low-carbon typologies. Every micro-grid developed in this chapter contained some amount of dispatchable distributed energy resource (DER), leading to an examination as to why a PV + storage only micro-grid would be unlikely. With the apparent need for micro-grids to contain some amount of distributable generation, a relatively small social cost of carbon of $50 per ton of CO2 ensures that every micro-grid would consist of primarily low-no emission DERs.