Geothermal energy is increasingly recognized for its potential to reduce carbon emissions and U.S. dependence on foreign oil. Energy and environmental analyses are critical to developing a robust set of geothermal energy technologies. This report summarizes what is currently known about the life cycle water requirements of geothermal electric power-generating systems and the water quality of geothermal waters. It is part of a larger effort to compare the life cycle impacts of large-scale geothermal electricity generation with other power generation technologies. The results of the life cycle analysis are summarized in a companion report, Life Cycle Analysis Results of Geothermal Systems in Comparison to Other Power Systems. This report is divided into six chapters. Chapter 1 gives the background of the project and its purpose, which is to inform power plant design and operations. Chapter 2 summarizes the geothermal electricity generation technologies evaluated in this study, which include conventional hydrothermal flash and binary systems, as well as enhanced geothermal systems (EGS) that rely on engineering a productive reservoir where heat exists but water availability or permeability may be limited. Chapter 3 describes the methods and approach to this work and identifies the four power plant scenarios evaluated: a 20-MW EGS …

Over a period of 30 years, more than a hundred Zero Power Reactor (ZPR) critical assemblies were constructed at Argonne National Laboratory. The ZPR facilities, ZPR-3, ZPR-6, ZPR-9 and ZPPR, were all fast critical assembly facilities. The ZPR critical assemblies were constructed to support fast reactor development, but data from some of these assemblies are also well suited for nuclear data validation and to form the basis for criticality safety benchmarks. A number of the Argonne ZPR/ZPPR critical assemblies have been evaluated as ICSBEP and IRPhEP benchmarks. Of the three classes of ZPR assemblies, engineering mockups, engineering benchmarks and physics benchmarks, the last group tends to be most useful for criticality safety. Because physics benchmarks were designed to test fast reactor physics data and methods, they were as simple as possible in geometry and composition. The principal fissile species was {sup 235}U or {sup 239}Pu. Fuel enrichments ranged from 9% to 95%. Often there were only one or two main core diluent materials, such as aluminum, graphite, iron, sodium or stainless steel. The cores were reflected (and insulated from room return effects) by one or two layers of materials such as depleted uranium, lead or stainless steel. Despite their more …

The use of thorium in current or advanced light water reactors (LWRs) has been of interest in recent years. These interests have been associated with the need to increase nuclear fuel resources and the perceived non-proliferation advantages of the utilization of thorium in the fuel cycle. Various options have been considered for the use of thorium in the LWR fuel cycle including: (1) its use in a once-through fuel cycle to replace non-fissile uranium or to extend fuel burnup due to its attractive fertile material conversion, (2) its use for fissile plutonium burning in limited recycle cores, and (3) its advantage in limiting the transuranic elements to be disposed off in a repository (if only Th/U-233 fuel is used). The possibility for thorium utilization in multirecycle system has also been considered by various researchers, primarily because of the potential for near breeders with Th/U-233 in the thermal energy range. The objective of this project is to evaluate the potential of the Th/U-233 fuel multirecycle in current LWRs, with focus this year on pressurized water reactors (PWRs). In this work, approaches for ensuring a sustainable multirecycle without the need for external source of makeup fissile material have been investigated. The intent …

Concert presented at the UNT College of Music Winspear Performance Hall.