Climate change is no novelty – we witness its disastrous impact more and more by each day. Although we already started envisaging a future where the vitality of our societies is derived not from conventional fossil fuels, but from a sophisticated, clean, and steadfast energy source – the latest benchmarks tracked by leading global energy agencies show grim performance, thereby calling for an intervention. The exploration into Small Modular Nuclear Reactors (SMRs) could present a stable and likely journey towards this vision – offering a glimpse into a future where energy is not only abundant, but also conscientiously generated. SMRs are compact versions of traditional nuclear power plants, yet they bring additional advantages such as potential cost-effectiveness and adaptability to diverse locations and environments. These reactors promise to cater to our escalating energy demands while simultaneously upholding environmental integrity. However, as this research reveals, their implementation – particularly in Finland and Sweden – isn't without challenges. While SMRs offer potential benefits, the regulatory landscapes in both countries present formidable obstacles. Finland's regulatory body, known for its stringent oversight, ensures adherence to the highest safety standards. Yet, this rigor can sometimes be a double-edged sword – especially when navigating the dynamic realm of SMRs. In contrast, Sweden grapples with pronounced regulatory uncertainties and ambiguity, further complicated by historical public skepticism towards the nuclear sector. Safety perceptions in the nuclear industry often deviate towards feelings rather than quantifiable metrics. This underlines an ongoing debate: should we define an acceptable safety threshold or aim for absolute safety? Moreover, the intertwined nature of politics and large-scale nuclear projects necessitates well-considered, stable strategies to harness SMRs' potential. Focused on Finland and Sweden – countries with rich nuclear histories – this research offers a deep dive into the complex narrative of risks, opportunities, and strategic challenges surrounding SMRs in the Nordic context. It underscores the need for a nuanced approach that combines technological innovation with socio-political considerations.

Inramade politiska frågor är något de flesta medborgare frekvent exponeras för när observerareller deltar i den offentliga diskursen. I Sverige är kärnkraftsfrågan en viktig politisk frågasom präglas av flera olika inramade narrativ. I denna studie undersökes hur fyra olika vanligtförekommande kärnkrafts-inramningar påverkar svenskars attityder till Sveriges nutida ochframtida användning av kärnenergi i energiförsörjningen. Detta genomfördes via ettsurveyexperiment (n=202). Inga påtagliga effekter från ram-exponering på attityder tillkärnkraft kunde observeras för någon ram. De flesta svenska medborgarna tycks ha ganskafasta övertygelser i kärnkrafts-frågan, och låter ej sina attityder förändras med lätthet.Vänster-högerideologi identifierades som en mycket avgörande faktor i hur svenskarna ställersig i denna politiska fråga, och mycket övertygande fenomen torde krävas för att dessa skallförändra inställningarna, åtminstone på kort sikt. / Framed political issues are something most citizens are frequently exposed to when observingor participating in the public discourse. In Sweden, the nuclear power issue is an importantpolitical issue that is characterized by several different framed narratives. This study examineshow four different commonly occurring nuclear power frames affect Swedes’ attitudes towardSweden’s current and future use of nuclear energy in its energy supply. This was investigatedvia a survey experiment (n=202). No significant effect from frame-exposure to attitudestoward nuclear energy could be observed for any frame. Most Swedish citizens seems to havefairly stable beliefs in this issue, and do not let their attitudes get influences with ease. Leftrightideology was identified a decisive factor in Swedes attitudes toward this issue, and avery convincing phenomena is required to change these attitudes, at least in the short term.

The Generation IV International Forum (GIF) has initiated an international collaboration for the research and development of the Generation IV future nuclear energy systems. The Canadian PT-SCWR is Canada’s contribution to the GIF as a GEN-IV advanced energy system. The PT-SCWR is a pressure tube reactor type and considered as an evolution of the conventional CANDU reactor. The PT-SCWR is characterized by bi-directional coolant flow through the High Efficiency Re-entrant Channel (HERC). The Canadian SCWR is a unique design involving high pressure and temperature coolant, a light water moderator, and a thorium-plutonium fuel, and is unlike any operating or conceptual reactor at this time. The SCWR does share some features in common with the BWR configuration (direct cycle, control blades etc…), CANDU (separate low temperature moderator), and the HTGR/HTR (coolant with high propensity to up-scatter), and so it represents a hybrid of many concepts. Because of its hybrid nature there have been subtle feedback effects reported in the literature which have not been fully analyzed and are highly dependent on these unique characteristics in the core. Also given the significant isotopic changes in the fuel it is necessary to understand how the feedback mechanisms evolve with fuel depletion. Finally, given the spectral differences from both CANDU and HTR reactors further study on the few-energy group homogenization is needed. The three papers in this thesis address each one of these issues identified in literature. Models were created using the SCALE (Standardized Computer Analysis for Licensing Evaluation) code package. Through this work, it was found that the lattice is affected by more than one large individual phenomenon but that these phenomena cancel one another to have a small net final change. These phenomena are highly affected by the coolant properties which have major roles in neutron thermalization process since the PT-SCWR is characterized by a tight lattice pitch. It was observed that fresh and depleted fuel have almost similar behaviour with small differences due to the Pu depletion and the production of minor actinides, 233U and xenon. It was also found that a higher thermal energy barrier is recommended for the two-energy-group structure since the PT-SCWR is characterized by a large coolant temperature compared to the conventional water thermal reactors. Two, three and four optimum energy group structure homogenizations were determined based on the behaviour of the neutron multiplication factor and other reactivity feedback coefficients. Robust numerical computations and experience in the physics of the problem were used in the few-energy group optimization methodology. The results show that the accuracy of the expected solution becomes highly independent of the number of energy groups with more than four energy groups used. / Thesis / Doctor of Philosophy (PhD)

Over the last two decades, there has been widespread international interest in the development of the molten salt reactor concept due to its passive safety, high coolant boiling temperature, low operational pressure, high thermal efficiency, and ease of breeding. Terrestrial Energy Incorporated (TEI) is developing a thermal-spectrum converter type molten salt reactor, called the Integral Molten Salt Reactor (IMSR-400) to be built by 2030. A physics experiment is needed in order to validate the theoretical predictions of the temperature reactivity coefficients of the IMSR-400. This thesis will determine the feasibility of conducting a subcritical experiment, utilizing a Deuterium-Deuterium Fusion Neutron Source (DD). / Thesis / Master of Science (MSc)

No description available.

The promotion of sustainable development is an objective shared by African Union (AU) member states and the pursuance thereof is expressly mandated by the Constitutive Act of the African Union, 2000 and the Treaty Establishing the African Economic Community, 1992. Lack of access to modern energy sources, such as electricity and the heavy reliance on traditional biomass as primary energy source are factors contributing to the non-achievement of the promotion of sustainable development. These factors are collectively referred to as energy poverty. The African Continent as a whole has limited, and in some instances, lack access to modern energy sources while the majority of its population relies heavily on traditional biomass as primary energy source. Africa can accordingly be classified as an energy poor region–a situation which does not bode well for the promotion of sustainable development. Access to reliable, affordable, economically viable, socially acceptable and environmentally sound energy services and resources is fundamental to socio-economic development. Mitigating the impacts of energy poverty and more specifically lack of access to modern energy sources on the sustainable development of Africa depends upon ensuring increased access to modern energy sources. The above-mentioned instruments furthermore contain provisions which link regional cooperation on the formulation of coordinated regional law and policy on areas/matters of common concern with the achievement of the objective of promoting sustainable development in Africa. One of the areas of common concerns listed is that of energy. Regional cooperation must accordingly be geared towards the effective development of the continent‘s energy and natural resources; promoting the development of new and renewable energy in the framework of the policy of diversification of sources of energy; and establishing an adequate mechanism of concerted action and coordination for the collective solution of the energy development problems within the AU. The formulation of coordinated energy law and policy should take place with reference to the specific sources of energy to be regulated. In this regard, the provisions of the Abuja Treaty and other sub-regional energy access initiatives list various sources of energy as forming part of a diversified AU energy mix – one of which is nuclear energy. In this study recommendations are made as to what should be embodied in a coordinated AU regional nuclear legal framework aimed at regulating increased access to nuclear energy capable of contributing towards the promotion of sustainable development. The recommendations are based on an examination of relevant international, regional and sub-regional legal instruments and other initiatives. / PhD (Law), North-West University, Potchefstroom Campus, 2014

This thesis compares the electoral programmes of green political parties in the Federal Republic of Germany, the Republic of Austria, and the Czech Republic in the years 1990- 2014, namely the German party Alliance '90/The Greens, the Austrian party The Greens - The Green Alternative, and the Czech Green Party. The beginning of the work provides an explanation of the concepts related to green politics, such as ecology, environmentalism, environment and sustainable development, whose knowledge is essential for understanding the major themes of the electoral programmes. Subsequently, the origin and history of all three political parties are outlined. The actual comparison is performed in a twofold manner. The first one compares the content of a specific programme with the previous ones and the second one compares the programmes of all three green parties for the same or the close electoral period. Furthermore, the format of individual programmes is characterized. Attention is focused on the major thematic areas, similarities and differences, and on the position of these parties before and after a particular parliamentary election being held.

La plupart des travaux portant sur la politique et la contestation de l’énergie nucléaire étudient des enjeux de mobilisations locaux et nationaux. Cette thèse a pour but de montrer que si les théories de la « nouvelle gouvernance » défendent l’hypothèse d’un dépassement de l’État, elles ne permettent pas de suffisamment saisir les dilemmes et les blocages de la transnationalisation de la cause anti-nucléaire. A partir de travaux de la sociologie des mouvements sociaux, des réseaux et de la sociologie politique, cette thèse vise à mieux comprendre la genèse et les modalités de la coopération et de la concurrence des Verts européens, des ONG environnementales telles que Greenpeace et Les Amis de la Terre, et des groupes locaux et nationaux. De la première conférence internationale des Nations Unies sur l'environnement de Stockholm en 1972 à la conférence sur le changement climatique de Copenhague en 2009, cette thèse étudie pourquoi et comment les militants se saisissent d’opportunités politiques internationales ou européennes. Elle explicite deux dilemmes de la coopération transnationale, à savoir la diversité des contraintes nationales des champs politiques et le degré d’institutionnalisation des groupes de contestation. Elle analyse enfin comment les militants établissent les règles de fonctionnement d’un capital social transnational comme « bien collectif » qui facilite la production, la circulation et la réception de différents types de ressources et de compétences sociales pour les militants. Loin de céder aux sirènes de l’avènement d’une « société civile transnationale », ce travail insiste sur la grande hétérogénéité pdes militants, profondément ancrés dans des champs politiques nationaux. Cette situation explique que l’activisme transnational en Europe demeure provisoire et discontinu. / Most of the work about the politics and contention of nuclear energy deal with local and national issues. This thesis aims to show that « new governance » theories, speaking about the decline of the state, cannot capture properly enough the various dilemmas and conflicts that prevent the rise and dynamic of the transnationalisation of the antinuclear cause. Based on social movement sociology, network sociology and political sociology, this work studies the incremental cooperation between green political parties, environmental NGO’s such as Greenpeace and Friends of the Earth, and last but not the least, local and national protest groups from the beginning of the 1970’s to the end of the 2000’s. From the first United Nation International Conference on the Environment of Stockholm in 1972 to the International Conference on Climate Change of Copenhagen in 2009, this thesis show why and how transnational activists perceive and size political international and European opportunities. It shows as well how activists face two kinds of dilemmas that prevent further transnational cooperation: the widediversity of constraints of political fields and the degree of institutionalization of antinuclear groups. It focuses on how antinuclear activists become able to build up rules of transnational social capital, understood as a “collective good” that may well facilitate the production, circulation and reception of different types of social resources and competences for activists. Far from turning a blind eye on the contradictions of what could be seen as a « transnational civil society », this work emphasizes the heterogeneity of activists, who remain deeply rooted into national political fields. This situation explains why transnational activism in Europe is still temporary and discontinuous.

Ce travail de thèse s’inscrit dans le domaine de l’énergie nucléaire, de l’aval du cycle du combustible et du calcul des incertitudes. Le CEA doit concevoir le prototype ASTRID, réacteur à neutrons rapides refroidi au sodium (RNR), qui est l’un des concepts retenus au sein du forum Génération IV et dont la puissance résiduelle et l’estimation de son incertitude ont un impact important. Ce travail consiste à développer un code de propagation des incertitudes des données nucléaires sur la puissance résiduelle dans les RNR.La démarche s’est déroulée en trois temps.La première étape a permis de limiter le nombre de paramètres intervenant dans le calcul de la puissance résiduelle. Pour cela, un essai de puissance résiduelle sur le réacteur PHENIX (PUIREX 2008) a été interprété de façon à valider expérimentalement le formulaire d’évolution DARWIN pour les RNR et à quantifier les termes sources de la puissance résiduelle.La deuxième étape a eu pour but de développer un code de propagation des incertitudes : CyRUS (Cycle Reactor Uncertainty and Sensitivity). Une méthode de propagation déterministe a été retenue car elle permet des calculs rapides et fiables. Les hypothèses de linéarité et de normalité qu’elle entraîne ont été validées théoriquement. Le code a également été comparé avec succès à un code stochastique sur l’exemple de la fission élémentaire thermique de l’235U.La dernière partie a été une application du code sur des expériences de puissance résiduelle d’un réacteur, de bilan matière d’une aiguille combustible et d’une fission élémentaire de l’235U. Le code a démontré des possibilités de retour d’expériences sur les données nucléaires impactant l’incertitude de cette problématique.Deux résultats principaux ont été mis en évidence. Tout d’abord, les hypothèses simplificatrices des codes déterministes sont compatibles avec un calcul précis de l’incertitude de la puissance résiduelle. Ensuite, la méthode développée est intrusive et permet un retour d’expérience sur les données nucléaires des expériences du cycle. En particulier, ce travail a montré qu’il est déterminant de mesurer précisément les rendements de fission indépendants et de déterminer leurs matrices de covariances afin d’améliorer la précision du calcul de la puissance résiduelle. / This PhD study is in the field of nuclear energy, the back end of nuclear fuel cycle and uncertainty calculations. The CEA must design the prototype ASTRID, a sodium cooled fast reactor (SFR) and one of the selected concepts of the Generation IV forum, for which the calculation of the value and the uncertainty of the decay heat have a significant impact. In this study is developed a code of propagation of uncertainties of nuclear data on the decay heat in SFR.The process took place in three stages.The first step has limited the number of parameters involved in the calculation of the decay heat. For this, an experiment on decay heat on the reactor PHENIX (PUIREX 2008) was studied to validate experimentally the DARWIN package for SFR and quantify the source terms of the decay heat.The second step was aimed to develop a code of propagation of uncertainties : CyRUS (Cycle Reactor Uncertainty and Sensitivity). A deterministic propagation method was chosen because calculations are fast and reliable. Assumptions of linearity and normality have been validated theoretically. The code has also been successfully compared with a stochastic code on the example of the thermal burst fission curve of 235U.The last part was an application of the code on several experiments : decay heat of a reactor, isotopic composition of a fuel pin and the burst fission curve of 235U. The code has demonstrated the possibility of feedback on nuclear data impacting the uncertainty of this problem.Two main results were highlighted. Firstly, the simplifying assumptions of deterministic codes are compatible with a precise calculation of the uncertainty of the decay heat. Secondly, the developed method is intrusive and allows feedback on nuclear data from experiments on the back end of nuclear fuel cycle. In particular, this study showed how important it is to measure precisely independent fission yields along with their covariance matrices in order to improve the accuracy of the calculation of the decay heat.

This thesis is based on the assumption that the intersection of moral philosophy and practical risk management is a rewarding area to study. In particular, the thesis assumes that concepts, ideas, and methods that are used in moral philosophy can be of great benefit for risk analysis, but also that practices in risk regulation provide a useful testing ground for moral philosophical theories. The thesis consists of an introduction and five articles. Article I is a review article on social and ethical aspects of radiation protection related to nuclear power generation. The paper concludes that four areas of social and ethical issues stand out as central: The first is uncertainty and the influence of value judgments in scientific risk assessments. The second is the distributions of risks and benefits between different individuals, in both space and time. The third is the problem of setting limits when there is no known level of exposure associated with a zero risk. The fourth is related to stakeholder influence and risk communication. Article II discusses ethical issues related to the proposal that doses (or risks) below a certain level should be excluded from the system of radiation protection, without any regard for the number of people exposed. Different arguments for excluding small radiation doses from regulation are examined and a possible solution to the problem of regulating small risks is proposed in the article: Any exclusion of small doses (or risks) from radiation protection ought to be based on a case-by-case basis, with the condition that the expected value of harm remains small. Article III examines what makes one distribution of individual doses better than another distribution. The article introduces a mathematical framework based on preference logic, in which such assessments can be made precisely in terms of comparisons between alternative distributions of individual doses. Principles of radiation protection and from parallel discussions in moral philosophy and welfare economics are defined using this framework and their formal properties analyzed. Article IV argues that the ethical theory of “responsibility-catering prioritarianism” is well positioned to deal with the reasonable requirements in an ethical theory of risk. The article shows how responsibility-catering prioritarianism can be operationalized using a prioritarian social welfare function based on hypothetical utilities. For this purpose, a hypothetical utility measure called ‘responsibility-adjusted utility’ is proposed, which is based on the utility that would normally be expected given circumstances outside of the control of the individual. Article V was written as a response to the Fukushima disaster. Several authors have called the Fukushima disaster a ‘black swan.’ However, the article argues that the hazards of large earthquakes and tsunamis were known before the accident, and introduces and defines the concept of a ‘black elephant,’ as (i) a high-impact event that (ii) lies beyond the realm of regular expectations, but (iii) is ignored despite existing evidence. / QC 20120816