Technology to recover uranium from seawater may act as a potential backstop on the production cost of uranium in a growing international nuclear industry. Convincing proof of the existence of an effective expected upper limit on the resource price would have a strong effect on decisions relating to deployment of uranium resource consuming reactor technologies. This evaluation proceeds from a review of backstop technologies to detailed analyses of the production cost of uranium extraction via an amidoxime braid adsorbent system developed by the Japan Atomic Energy Agency (JAEA). An independent cost assessment of the braid adsorbent system is developed to reflect a project implemented in the United States. The cost assessment is evaluated as a life cycle discounted cash flow model to account for the time value of money and time-dependent performance parameters. In addition, the cost assessment includes uncertainty propagation to provide a probabilistic range of uranium production costs for the braid adsorbent system. Results reveal that uncertainty in adsorbent performance (specifically, adsorption capacity, kg U/tonne adsorbent) is the dominant contributor to overall uncertainty in uranium production costs. Further sensitivity analyses reveal adsorbent capacity, degradation and production costs as key system cost drivers. Optimization of adsorbent performance via alternate production or elution pathways provides an opportunity to significantly reduce uranium production costs. Finally, quantification of uncertainty in production costs is a primary policy objective of the analysis. Continuing investment in this technology as a viable backstop requires the ability to assess cost and benefits while incorporating risk. / text

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The regulation of atomic energy has had a long and unique history in the United States and it is the effectiveness of that regulation which poses the problem analyzed here. Government documents and secondary sources are used to provide data and critical opinion about atomic energy regulation. The first chapter deals with the history of the earliest attempts to deal vith atomic energy while the second chapter is concerned with the political nature of the Atomic Energy Commission (AEC). Questions o secrecy and potential environmental danger from the nuclear enterprise are topics for the third and fourth chapters respectively. A concluding chapter indicates the future direction the regulation of nuclear power may take under the newly established Nuclear Regulatory Commission and the Energy Research and Development Administration.

The energy sector faces sustainability challenges that are re-working the established patterns of energy supply, distribution and consumption (Anderson et al. 2008; Haas et al. 2008; Stern 2008; Shove and Walker 2010). Amidst these challenges, socio-technical energy transitions frameworks have evolved that focus on transitions towards decarbonised, sustainable energy systems (Bridge et al. 2013). However, the ‘socio-‘ or social is typically missing as we confront climate and energy risks in a moral vacuum (Sovacool et al. 2016). The energy justice framework provides a structure to think about such energy dilemmas. However, the full extent and diversity of justice implications within the energy system have been neglected. Thus, borrowing from and advancing the framework this research explores how energy justice is being articulated with attention to three emergent areas of growth, the themes of: (1) time, (2) systems component and (3) actor. It does so through a case study of nuclear energy, which was chosen because of its points of enquiry with regards to these three areas of growth, and its historical and on-going importance in the UK energy mix. Using results from 36 semi-structured interviews with non-governmental organisations and policy actors across two case studies representative of the nuclear energy stages of energy production and of waste storage, disposal and reprocessing – the Hinkley Point and Sellafield nuclear complexes – this research presents new insights within each of these previously identified areas of development. It offers the contributions of (1) facility lifecycles, (2) systems approaches and (3) the question of ‘justice by whom?' and concludes that the energy justice framework can aid energy decision-making in a way that not only mitigates the environmental impacts of energy via socio-technical change, but also does so in an ethically defensible, socially just, way.

Harms produced by nuclear energy include the accident risks of population displacement, deaths, cancers, genetic, teratogenetic (affecting embryo and foetus) and psycho-social effects; increased radiation exposure to workers, locals and future generations from nuclear plants, uranium mines and waste storage facilities; thermal and toxic tailings pollution from nuclear plants and uranium mines; and other unknown long-term effects of increasing levels of background radiation. Historically, most greens have opposed nuclear energy alongside nuclear weapons. Recently, however, significant green spokespeople have combined with industry and governments in emphasising the need for nuclear energy in response to climate change. Based upon my experiences in the struggle against the Hinkley C nuclear power plant in Somerset, UK, this thesis contests the dominant framings of the debate. I suggest that arguments for nuclear energy are made possible by reductive understandings of the issue making it difficult to apprehend the significance of harms reinforced by nuclear energy. Taking an ecological approach I show how dominant discourses presuppose a hierarchical separation of science/politics, reinforced by and reinforcing the separation of nature/culture. These hierarchical separations depoliticise and naturalise harms produced by both nuclear energy and dominant forms of social organisation. As a result, these harms are difficult to communicate and contest as relevant to the discussion of our common futures. In this thesis I argue that we might more effectively convey the significance of these harms if we articulate them as injustices. Building upon the theory and practice of justice and liberation struggles I develop a heuristic framework for articulating injustices based around three intersecting images of politics as distribution, recognition and representation. I suggest articulating injustices of nuclear energy as i) the deprivation of basic necessities due to unequal distributions of burdens as well as goods; ii) the disrespect for ecological integrity due to desire for control of inevitable unpredictability in interaction; and iii) the denial of multiple authorities through monopolisation of rational speech and action and disengaged forms of knowledge production. Expressing harms of nuclear energy by way of this three-fold articulation of injustices politicises nuclear energy, climate change, and the dominant forms of social organisation, opening these up to political contestation to more effectively take ‘all affected’ into account before we reconsider how we might live together.

The Liquid Salt Cooled Reactor (LSCR) provides several potential benefits compared to pressurized water-cooled reactor systems. These include low operating pressure of the liquid salt coolant, the high burnup tolerance of the fuel, and the high operating temperatures which leads to increases in efficiency. However, due to inherently low heavy metal loading, the fuel cycle design presents specific challenges. In order to study options for optimizing the fuel design and fuel cycle, SCALE6.1 was used to create simplified models of the reactor and look at various parameters. The primary parameters of interest included packing factor and fuel enrichment. An economic analysis was performed on these results by developing a simple fuel cycle cost (FCC) model that could be used to compare the different options from an economic standpoint. The lithium enrichment of the FLiBe coolant was also investigated. The main focus was to understand the practical limitations associated with the Li-7 enrichment and whether it could be used for beneficial purposes. The main idea was to determine whether a lower-than-equilibrium enrichment could be used at reactor start up so that the Li-6 isotope acts as a burnable absorber. The results for the lithium enrichment study showed that the enrichment converges over time, but the amount of time required to reach steady state is much too long and the FLiBe coolant could not be utilized for reactivity control as a burnable absorber. The results found through this research provide reasonable guidelines for expected costs and narrow down the types of configurations that should be considered as fuel design options for the LSCR. Additionally, knowledge was gained on methods for modeling the system not only accurately but also efficiently to reduce the required computing power and time.

M. Tech. Business Administration / The study of perceptions on nuclear energy programmes in South Africa was aimed at a small population of students with special focus on first-year students studying in UJ, in any field of study. Quantitative data was collected using a questionnaire. Descriptive analysis was done. The perceptions were directed towards nuclear energy programmes thus determining the causes or reasons behind their perceptions and recommend r aspects to be considered as corrective measures, to combat the perceptions. These include educating the public about nuclear energy, involving the public and allowing their participation at an early stage and using better communication platforms for nuclear related public communication.

The objective of this thesis was to design a canister for the disposal of spent nuclear fuel and other high-level waste in deep borehole repositories using currently available and proven oil, gas, and geothermal drilling technology. The canister is suitable for disposal of various waste forms, such as fuel assemblies and vitrified waste. The design addresses real and perceived hazards of transporting and placing high-level waste, in the form of spent reactor fuel, into a deep igneous rock environment with particular emphasis on thermal performance. The proposed boreholes are 3 to 5 km deep, in igneous rock such as granite. The rock must be in a geologically stable area from a volcanic and tectonic standpoint, and it should have low permeability, as shown in recent data taken from a Russian deep borehole. Although deep granite should remain dry, water in flooded boreholes is expected to be reducing, but potentially corrosive to steel. However, the granite and plug are the containment barrier, not the canister itself. The canisters use standard oil drilling casings. The inner diameter is 315.32mm in order to accommodate a PWR assembly with a width of 214mm. At five meters tall, each canister holds one PWR assembly. The canister thickness is 12.19mm, with an outer diameter of 339.7mm. A liner can extend to the bottom of the emplacement zone to aid in retrievability. The liner has an outer diameter of 406.4mm and a thickness of 9.52mm. The standard drill bit used with a liner of this size has an outer diameter of 444.5mm. / Contract number: N62271-97-6-0026. / US Navy (USN) author.

Recently, attention has been drawn to the viability of using S-CO(2) as a working fluid in modern reactor designs. Near the critical point, CO2 has a rapid rise in density allowing a significant reduction in the compressor work of a closed Brayton Cycle. Therefore, 45% efficiency can be achieved at much more moderate temperatures than is optimal for the helium Brayton cycles. An additional benefit of the S-CO2 system is its universal applicability as an indirect secondary Power Conversion System (PCS) coupled to most GEN-IV concept reactors, as well as fusion reactors. The United States DOE's GNEP is now focusing on the liquid Na cooled primary as an alternative to conventional Rankine steam cycles. This primary would also benefit from being coupled to an S-CO2 PCS. Despite current progress on designing the S-CO2 PCS, little work has focused on the principal supporting systems required. Many of the required auxiliary systems are similar to those used in other nuclear or fossil-fired units; others have specialized requirements when CO2 is used as the working fluid, and are therefore given attention in this thesis. Auxiliary systems analyzed within this thesis are restricted to those specific to using CO2 as the working fluid. Particular systems discussed include Coolant Make-up and Storage, Coolant Purification, and Coolant Leak Detection. / Contract number: N62271-97-G-0026. / US Navy (USN) author