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The development of nuclear energy technologies in the second half of the 20th century came with great hopes of rebuilding nations recovering from the devasta-tion of the Second World War or recently released from colonial rule. In coun-tries like France, India, the USA, Canada, Russia, and the United Kingdom, nuclear energy became the symbol of development towards a modern and technologically advanced future. However, after more than six decades of experi-ence with nuclear energy production, and in the aftermath of the Fukushima nuclear disaster, it is safe to say that nuclear energy production is not without its problems.Some of these problems have their origins in the very materiality of the technolo-gies involved. For example, not only does the use of highly radioactive materials give rise to risks for the current generation (e.g., in the potential for disaster when reactors melt down) but high-level radioactive waste from nuclear energy production presents a serious intergenerational problem for which an acceptable final solution or its implementation remains elusive. Moreover, nuclear energy technologies have specific social and political consequences. For example, they have been said to be authoritarian technologies (Winner, 1980), requiring cen-tralized authority, secrecy, and technocratic decision-making. While some of these problems could have been foreseen before nuclear energy technologies were introduced, others only arose after these technologies were already integrated into the social and infrastructural fabric of our lives. Addition-ally, new technologies (e.g., Generation III, III+ and IV reactors) are still being developed, bringing with them new and uncertain hazards and risks. Ignorance and uncertainty about the possible deleterious effects of introducing a new technology are inevitable, especially if the technology is complex, large time-scales are involved, or risks depend on social or political factors unforeseen in the design stage. However, this should not deter us from developing and intro-ducing new technologies. Rather, it should motivate us to organize these ‘exper-iments’ with new technologies in society in such a way that we can learn about their possible hazards and risks as effectively and responsibly as possible (van de Poel, 2011, 2015). In this way, it is possible to minimize risks and avoid unwant-ed moral, social or political developments. However, organizing such experi-ments responsibly also means that one could come to the conclusion that continuing an experiment is no longer responsible or desirable. Should we be prepared for such a scenario, and if so, how could we do that? One possible strategy to tackle this issue is that the technology and its introduction should be reversible. The aim of this thesis is to further explore this strategy by answering the following main research question (RQ) and accompanying subquestions (SQ):RQ: What are the implications of reversibility for the responsible develop-ment and implementation of nuclear energy technologies?SQ1: Under what conditions can nuclear energy technologies be considered reversible?SQ2: Why should nuclear energy technologies be reversible?SQ3: If so, how could the reversibility of nuclear energy technologies be achieved?After the introductory chapter 1, the chapters that form the main body of this dissertation each provide a distinct contribution to answering the three subques-tions and, by extension, the main research question. Guided by three historical case studies of nuclear energy technology development (i.e., India, France and the USA), chapter 2 answers the first subquestion by formulating the two condi-tions under which it can be considered reversible, i.e., 1) the ability to stop the further development and deployment of a that technology in society, and 2) the ability to undo the undesirable outcomes (material, institutional or symbolic) of the development and deployment of the technology. Chapter 3 subsequently tackles the second subquestion by establishing the general desirability of technological reversibility by virtue of its relation to responsibility in Emmanuel Levinas’ ethical phenomenology. It argues that technology development is a legitimate response to responsibility but inevitably falls short of the responsibility that inspires it, incessantly calling for technological and political change in the process. Having thus argued that nuclear energy technologies should ideally be reversible, chap-ters 4 and 5 work towards specific strategies to achieve technological reversibil-ity. Chapter 4 first investigates the processes that make it difficult to stop the further development and implementation of a nuclear energy technology in society, thus provid-ing input on how to fulfill the first condition for the reversibility of nuclear energy technologies. To do so, it presents a phenomenological perspective on technology and its adoption based on the work of Alfred Schutz. It also explores different ways in which technology adoption drives the processes of path depend-ence towards technological lock-in. Chapter 5 examines the history of geological disposal of high-level radioactive waste in the USA. It identifies a number of concrete policy pitfalls that could lead to lock-in and that should consequently be avoided. It also presents a number of general design strategies that could facilitate the undoing of undesirable consequences of a technology, thus providing input on how to fulfill the second condition for the reversibility of nuclear energy technol-ogies.Chapter 6 summarizes the central findings of the thesis and explains how these help to answer the research questions. On top of this, it reflects on a number of complications connected to reversibility considerations. Based on this, it is concluded that the question of irreversibility and reversibility is context- and technology-specific and a matter of degree. The chapter concludes with a reflec-tion on generalizations and limitations of the results. Finally, chapter 7 discusses the implications of this dissertation’s results for responsibly experimenting with nuclear energy technologies in society. Ethics & Philosophy of Technology

Energy conversion systems have assumed a crucial role in current society. The threat of climate change, fossil fuel depletion and the growing world energy demand ask for a more sustainable way of electricity production, eg, by using renewable energy sources, by improving the conversion efficiency and/or by controlling power plant emissions. Despite the relationship between exergy and sustainability stated in literature, exergy losses are usually not considered when comparing systems and energy sources for power generation. The exergetic sustainability assessment method named Total Cumulative Exergy Loss (TCExL) has been used to assess several systems for electricity production, ie, a coal-fired power plant, a coal-fired power plant including carbon capture and storage, a biomass-fired power plant, an offshore wind farm and a photovoltaic park. The results of the TCExL method have been compared with an environmental sustainability indicator, ie, the overall ReCiPe endpoint indicator and the economic indicator named Present Worth Ratio. The offshore wind farm is the best system from the exergetic and environmental point of view. The photovoltaic park is the system with the second-best scores. However, from the economic viewpoint including subsidy by the Dutch government, the photovoltaic park performs better than the wind farm system and the system that performs best is the biomass-fired power plant. Without subsidy, only the coal-fired power plant without carbon capture and storage is profitable. The exergetic sustainability scores of the coal-fired and biomass-fired power plants are similar, but from the environmental sustainability viewpoint, the biomass-fired power plant performs better than both coal-fired power plants. As the results of environmental and economic sustainability assessments strongly depend on models, weighting factors, subsidy, market prices, etc, while the results of the exergetic sustainability assessment do not, it is recommended that the exergetic sustainability be taken into account when assessing the sustainability of power generation and other technological systems. Energie and Industrie Reservoir Engineering

Nuclear safety governance should move towards a more robust regime including elements of international monitoring and verification. This is needed because nuclear energy production is likely to grow and new reactors will have different global dispersal, veering towards less experienced countries. In addition, there is growing interest in international and multilateral collaboration on disposal of mounting nuclear waste. Unlike existing improvements that came in response to nuclear disasters (by accident), it makes sense to implement all these elements at once (by design). While a comprehensive global governance regime must include elements of verification and enforcement, more transparent international oversight would also improve global nuclear safety through public pressure. The monitoring and enforcement of such a globally organized regime could be introduced at regional or otherwise supranational level. In this paper, we argue that a robust global nuclear safety regime is not only necessary but also feasible provided it manages to address the following potential hurdles: i) the tensions in international security politics, ii) the stickiness of national sovereignty and iii) industry resistance to additional restrictions and to issues of proprietary commercial information. These objections will be elaborately reviewed in the paper. Ethics & Philosophy of Technology

Many energy researchers and practitioners envision householders to have an active role in local energy distribution in emerging energy systems. In the energy literature, the dominant view of local energy distribution, grounded in the rational choice perspective, sees exchanges of energy between households as energy trading. The existing energy literature lacks conceptualization of social and personal exchange of energy between households that is mutually structured and negotiated. This article builds on the theoretical works of an economic anthropologist, Stephen Gudeman, to conceptually discuss such energy exchanges. This article reports from an ‘ethnographic intervention’ study conducted at an off-grid village in rural India for three months (1 February–30 April 2016). The ethnographic data analysis reveals how social relations and diverse cultural values influence on energy exchanges between households in the village. The article introduces ‘circle of mutual energy exchange’ as a conceptual, analytical and descriptive unit for understanding such energy exchanges. The article describes two co-existing and dialectically connected modes of energy exchanges: ‘mutual energy sharing’ and ‘mutual energy trading.’ Design Conceptualization and Communication

We present results of MD simulations of low energy He ion bombardment of low density fuzz in bcc elements. He ions can penetrate several micrometers into sparse fuzz, which allows for a sufficient He flux through it to grow the fuzz further. He kinetic energy falls off exponentially with penetration depth. A BCA code was used to carry out the same ion bombardment on the same fuzz structures as in MD simulations, but with simpler, 10 million times faster calculations. Despite the poor theoretical basis of the BCA at low ion energies, and the use of somewhat different potentials in MD and BCA calculations, the ion penetration depths predicted by BCA are only similar to 12% less than those predicted by MD. The MD-BCA differences are highly systematic and trends in the results of the two methods are very similar. We have carried out more than 200 BCA calculation runs of ion bombardment of fuzz, in which parameters in the ion bombardment process were varied. For most parameters, the results show that the ion bombardment process is quite generic. The ion species (He or H), ion mass, fuzz element (W, Ta, Mo, Fe) and fuzz element lattice parameter turned out to have a modest influence on ion penetration depths at most. An off-normal angle of incidence strongly reduces the ion penetration depth. Increasing the ion energy increases the ion penetration, but the rate by which ion energy drops off at high ion energies follows the same exponential pattern as at lower energies. (C) 2017 Elsevier B.V. All rights reserved. Peer reviewed

The imperative of realizing utopian visions of the smart grid puts unprecedented policy focus on standardization. Because standards are a prerequisite for deployment, the US federal government - in a departure from established hands-off practice - intervened to coordinate and accelerate standardization activities. This research uses narrative analysis to explore how such a policy of intervention was constructed. What emerges has elements of a hero story, describing a situation to be remedied: an aging electricity grid, plagued by blackouts and modernization hampered by an electric utility industry composed by stand-alone "silos". In contrast, the vision of a future "smart grid" with promises of improved energy security, reduced carbon emissions, renewable resources, "green innovation" and jobs. The threat: without standards, the risk that sizable public investments become obsolete prematurely. The villain: unnamed companies engaging in uncompetitive behavior. The unlikely hero: The National Institute of Standards and Technology, able to act as an "honest broker", proving that the government can as "catalyst" in partnership with industry. While succeeding in making a strong argument for government intervention, the story can be criticized for making exaggerated claims about the effects of standards, for downplaying the complexity of the process and for failure to outline policy alternatives beyond a five-year plan. Energie and Industrie

In recent years, awareness and concern about global warming from fossil fuels have notably grown. This process of global warming can, in part, be circumvented by the usage of renewable energy technology in homes. Two protocols exist that can realize wireless communications between sensors and electrical appliances on the one hand and the smart meter (which connects to a visual interface) on the other hand; Zigbee and Z-Wave. When one of these protocols is chosen, a home energy management system can be realized, allowing monitoring of the devices that consume energy in the home. There is no standard, and these two communication protocols are in a battle for dominance. This paper aims to find which factors could affect the outcome of this standards war in the Netherlands, and determine which protocol has more chances to achieve dominance. The factors that were determined as most important are compatibility, big fish, current installed base, and complementary goods, whereas, counterintuitively, technology superiority is one of the least relevant factors. It appears that Zigbee has a higher chance to achieve dominance. The paper concludes by discussing these results in light of the standardization literature. Economics of Technology and Innovation

In the present work, we combine experiments and numerical simulations of a planar jet with heated co-flow with medium (air) and low-Prandtl (He-Xe gas mixture) fluids. Jets are recognized as representative test cases to be investigated in large components of pool-type liquid metal-cooled nuclear systems, like the Multi-purpose hYbrid Research Reactor for High-tech Applications (MYRRHA), currently under design at SCK•CEN. The present planar jet configuration mimics a closed wind tunnel that is designed and operated at VKI to generate an experimental database for velocity and temperature fields of a turbulent forced-convection flow regime. The performed experiments combine the Particle Imaging Velocimetry (PIV) (in characteristic planes) and thermocouple (single point) measurements. In parallel with experiments, comprehensive numerical simulations have been performed within the RANS modeling framework. Next to the standard eddy-viscosity based two-equation k-ε model, an extended variant based on the low-Reynolds elliptic relaxation concept (so-called ζ-f model) has been applied too. To investigate the low-Prandtl effects on the heat transfer, series of the turbulent heat transfer models have been applied, ranging from a conventional constant turbulent Prandtl number to a more elaborate kθ-εθ model. The combination of the low-Reynolds ζ-f and kθ-εθ models was explored for the first time in the content of nuclear engineering applications. The focus of the numerical studies is to address in details the effects of low-Prandtl fluid in the strongly forced convection flow (central planar cold jet) in presence of a strong shear (hot co-flow). We demonstrate the importance of the proper specification of the inlet boundary conditions in numerical simulations to mimic correctly experimentally observed asymmetrical distributions of the cross-wise profiles of stream-wise velocity, turbulent kinetic energy and temperature. Finally, the minor differences in results between the assumed constant turbulent Prandtl number and more advanced kθ-εθ model of the turbulent heat flux confirmed the overly dominant mechanisms of the strong convection and molecular diffusion in the present configuration. ChemE/Transport Phenomena