The Nuclear Option: A Global Sustainability Appraisal of Civil Nuclear Energy

(1)

FACULTY OF ENGINEERING AND SUSTAINABLE DEVELOPMENT

Department of Building Engineering, Energy Systems and Sustainability Science

Sebastian Arnström

2020

Student thesis, Basic level (Bachelor degree), 15 HE Environmental Engineering

Environmental Strategist Supervisor: Karl Hillman

The Nuclear Option

(2)

(3)

Preface

I would like to thank my supervisor Karl Hillman for giving me valuable tips and criticisms throughout the work with my thesis. I am also grateful for the support of my sister Maja, my girlfriend, and my family and friends, who endured me ranting about the ins and outs of nuclear energy for six months. Finally, the work I have done is built on the efforts of brilliant researchers from all over the world. Hopefully, this thesis can make some small contribution to the epistemic base of sustainable energy development.

(4)

(5)

Abstract

Energy production systems are essential for human progress. They fuel the

technologies that underpin economic growth and are prerequisite for efficient food production, education and healthcare. On the flip side, they also incur substantial eco-social costs. Hence, finding and promoting sustainable means of energy production is a key topic within the Environmental Sciences. This thesis examines the sustainability of nuclear power, by comparing its social, economic and ecological impacts to those of wind and solar power. The assessment is performed using Multi-Criteria Analysis (MCA), with a Weighted Sum scoring system and a Distance-To-Target weighting scheme. The selection and the weighting of the indicators are grounded in the Planetary Boundaries framework, the Oxfam Doughnut Economics model and the UN’s Sustainable Development Goals, and the technologies are compared on 9 axes of evaluation; greenhouse gas emissions, land-take

requirements, material throughput, non-recyclable wastes, toxic and radioactive wastes, negative health impacts, economic costs, intermittency and energy return on energy invested. The thesis finds nuclear power to be the most sustainable option according to all but three indicators, and in the unified analysis, it outcompetes wind and solar by a factor of 2 and 3 respectively. Also notable is that solar power does not excel in a single impact category; it has the highest greenhouse gas emissions, the largest land-take, and it is costly, intermittent and energy-inefficient. It is also a source of toxic pollution, the effects of which cannot yet be determined. Although wind is more competitive, it consumes vast amounts of physical resources, generates a lot of waste, and its land-take is at least 10 times higher than that of nuclear

power. In addition to the MCA, the thesis investigates three perceived threats that are often raised in criticisms of nuclear power; the risk of nuclear fuel depletion, the risk of nuclear weapons proliferation and the risk of catastrophic nuclear accidents. The results show that many popular arguments against the technology are loosely aligned with reality, and the thesis as a whole presents a challenge to the notion that nuclear power is a dangerous and unsustainable energy source.

Keywords: nuclear power, solar power, wind power, sustainability, sustainable development, sustainable energy development, sustainability of nuclear power, nuclear accidents, nuclear weapons proliferation, nuclear fuel depletion

(6)

(7)

1 Background

Energy production systems (EPS) are essential for socio-economic progress. They fuel the technologies that underpin economic growth, such as efficient harvesting, manufacturing and agricultural equipment. Moreover, they are a prerequisite for social necessities like heating, refrigeration, ventilation and electric light, as well as modern education, transportation, healthcare and waste management systems (UNDP, 2000; GEA, 2012). On the flip side, they also have substantial eco-social costs. The combustion of fossil fuels drives anthropogenic global warming, which threatens to destabilize both human and biospheric communities. Besides

greenhouse gasses, the energy sector emits a multitude of harmful pollutants, including particulates, nitrogen oxides, volatile organic compounds, heavy metals and non-degradable wastes (Middleton, 2013). Moreover, the spatial requirements of EPS are becoming a key driver of land use change in modernized societies (e.g., Trainor et al., 2016). Hence, finding and promoting eco-socially sustainable EPS is a topic of key importance within the Environmental Sciences. Although there is an extensive literature comparing various energy sources, relatively few studies have been focused specifically on nuclear power. Following the assertion that no energy option should be dismissed out of hand, the present thesis assesses the sustainability of nuclear power, by comparing its social, economic and ecological impacts with those of wind and utility scale solar power; two energy sources that are widely recognized as sustainable (e.g., UN, 2016). This introductory chapter provides a contextual framework for the study, beginning with a brief explanation of the history and meaning of the term sustainable development. It then describes the world’s major sustainability challenges, before explicating on the relationship between energy production and sustainable development. Lastly, it gives a short history and technological description of nuclear, wind and solar power.

1.1 Sustainable Development

The term sustainable development is all but ubiquitous in contemporary discourse on social planning. It was first introduced in a 1987 report by the World

Commission on Energy and Development, titled Our Common Future. In it,

sustainable development is defined as “...development that meets the needs of the present without compromising the ability of future generations to meet their own needs” (WCED, 1987). The concept has since evolved to include three fundamental pillars of human progress; social, economic and ecological sustainability. For it to be sustainable, a measure that raises one of the pillars must not threaten the stability of the other two. For instance, measures towards economic value creation should not create social harm, or endanger the integrity of resource producing ecosystem services. Conversely, in initiatives towards environmental conservation, the social

(10)

and economic outcomes must not be ignored. Thus, to engender sustainable development, decision makers have to be mindful of the social, economic and ecological impacts of their undertakings, as well as their potential effects on the well-being of future generations (Purvis, Mao & Robinson, 2018; Ammenberg, 2012).

In an effort to put these principles into practice, the United Nations have declared 17 global development goals, (Figure 1). These insist that its member states work to create stable and equal societies, eradicate poverty and famine, and increase the access to modern healthcare, education and infrastructure–all without causing irreparable damage to the biosphere (UN, 2015).

Figure 1. The UN’s global development goals.

While broadly supported within the Environmental Sciences, some have criticized the goals for being vague and hard to implement. Another common criticism is that social and economic progress happens at the expense of ecological values (e.g., Swain, 2018). The UN’s goals are indeed ambitious–building a happier, healthier and greener world is a monumental task, made even harder by the sometimes contradictory socio-economic and ecological goal states. Using the UN’s development goals as a guide, the following chapters summarize the major sustainability challenges faced by the global community.

1.1.1 Social and Economic Sustainability

In the centuries following the Industrial Revolution, a series of scientific discoveries and technological innovations, alongside a continuing push for market economies and cosmopolitan ideals, led to a rapid systemization and technologization of the worlds societies (Mokyr, 2015; McNeil, 2002; Butler, 2011). Inventions like the steam engine, the generator and the combustion engine, together with the use of

(11)

fossil fuels and mechanized factory processes, initiated an era of unprecedented wealth creation and social progress (GEA, 2012; Hall et al., 2003). Since the early 1800’s, the global GDP per capita has increased by an order of magnitude, even though the world’s population has grown exponentially (Roser, 2019b, 2019d). Meanwhile, the average life expectancy has more than doubled, and the share of people who live in extreme poverty has fallen from 89% to 10% (Roser, 2019a, 2019c). The proportion of people who cannot read or write has gone from 88% to 14%, and the percentage of children who die before the age of five from 43% to 4%. More than half of the world’s population currently live in democracies, compared to 1% in the year 1800, and eight out of ten is vaccinated against

diphtheria, pertussis and tetanus (Roser, 2019c). As the UN’s global goals suggest, poverty reduction is the most fundamental step in engendering social progress. When nations become richer, living standards increase, and they allocate a larger fraction of their capital to social spending (Ortiz-Espinosa & Roser, 2019). Studies of subjective well-being has suggested that democratization, secularization and economic growth has made people not only healthier, wealthier and better fed, but happier and more socially tolerant as well (Stevenson & Wolfers, 2008; Ingelhart et al., 2008; Helliwell et al., 2016).

In spite of this historical trend towards increasing human progress, a number of challenges remain: As stated, a tenth of the world's population remain in extreme poverty and an estimated 821 million are undernourished. The number of children and teenagers who are not receiving an education amounts to 262 million. Child mortality continues to fall, along with the number of forced marriages involving young girls, and gender equality is steadily increasing. However, progress has stalled on curing some of the diseases that plague the developing world, such as malaria and tuberculosis. Roughly 3 billion people lack a proper means of washing their hands, as well as access to electric or gas driven cooking utensils. While developing nations experience high rates of economic growth, income inequality has increased in many richer countries. Lastly, the number of people fleeing from armed conflicts and political persecution has risen in the last decades and now amounts to 70 million (UN, 2019a).

1.1.2 Ecological Sustainability

As outlined above, the last two centuries have seen immense socio-economic

progress. However, many of humanity’s advances have incurred big ecological costs. Fossil fuel combustion emits greenhouse gases, such as carbon dioxide (CO2),

methane (CH4) and nitrous oxide (N2O). These allow shortwave radiation (sunlight)

to pass through the atmosphere, while trapping longwave radiation (heat) that is re-emitted from the planet’s surface. As CO2 and other greenhouse gases build up in

(12)

the atmosphere, the Earth’s mean temperature rises (NRC, 2010). According to Hoeg-Guldberg et al. (2014) the average global temperature has increased with roughly 1°C since the Industrial Revolution. If this warming continues, it may cause severe ecological problems, such as erratic weather patterns, sea-level rise, heavy rainfalls, storms and flooding, and regional droughts, heatwaves and wildfires. The rapid temperature changes affect the conditions in both terrestrial and aquatic ecosystems, putting species that are slow or unable to migrate, or narrowly adapted to their environments, at risk of extinction. Already, the flora of high-latitude biomes, such as tundra’s and boreal forests, are being outcompeted by species that have spread from lower-lying regions. Additionally, 30% of humanity’s CO2

-emissions have dissolved into the Earth’s oceans and is gradually acidifying the water. The projected impacts on human societies are equally profound, with food shortages, water scarcity, severe heat exposure and climate migration being likely outcomes. Moreover, the social problems caused by global warming will

disproportionately affect people who are already living in poverty, and thus

exacerbate existing patterns of inequality (Hoeg-Guldberg et al., 2018). To mitigate these risks, the UN’s Intergovernmental Panel on Climate Change has advised that the Earth’s temperature should be kept within 1.5°C above pre-industrial levels. For this to be achieved, the global carbon emissions must be lowered by half until the year 20301_{, followed by a complete phasing out of carbon emitting technologies}

before 2050 (Rogelj et al., 2018).

Figure 1.2. Arctic melt ponds.

Aside from global warming, the postindustrial growth period has resulted in a substantial expansion of the world’s built environments: Hooke and Martín-Duque

(13)

(2012) estimate that humans have modified more than half of the Earth’s terrestrial surfaces, while Ellis and Ramankutti (2008) conclude that 75% of all ice-free land is affected to the point that it can no longer be considered wild. As agricultural and built environments spread, they cause fragmentation and destruction of plant and animal habitats, and acts as barriers for migrating species. Hardened or impermeable surfaces prevent rainwater from infiltrating the ground, and cause flooding, soil erosion and reductions in groundwater recharge. Furthermore, cities, agriculture and industrial areas emit air and waterborne pollutants, toxins, plant nutrients, heavy metals and non-degradable wastes (Middleton, 2013; Hooke & Martín-Duque, 2012).

Figure 1.3. Sea turtle.

Land use change, global warming and pollution have been identified as the main drivers of biodiversity loss: Since the early 1900’s, the species richness in terrestrial ecosystems has fallen by 20%. The number of amphibian species has dropped by 40%, and 33% of all reef-forming corals and marine mammals are at risk of

extinction. The status of insect species is harder to ascertain, but an estimated 10% appear to be endangered. In total, one million plant and animal species are thought to be facing extinction. Maintaining biodiversity is necessary to protect many life-sustaining ecosystem services, such as healthy soils, air- and water purification, climate regulation, flood prevention and carbon sequestration in biomass. Thus, ecological conservation is a key issue in measures towards sustainable development (Diaz et al., 2019).

All of the problems outlined above can be attributed to humanity's use of natural resources. Hence, much of the work within the Environmental Sciences is aimed at developing models of sustainable consumption. While there is no consensus on how it could be achieved (Peatti & Collins, 2009), a number of measurements of

humanity’s overall resource use have been proposed. One is the ecological footprint concept (EF), which consists of a hypothetical ratio between the biosphere’s

(14)

EF methodology, the present rate of consumption would require 1.7 Earths to be sustainable (Lin et al., 2018). A more empirically grounded measurement can be found in the UN’s material footprint concept (MF), which focuses specifically on the per capita consumption of physical resources, such as biomass, metals and non-metal ores (UN, 2018). Although the MF methodology lacks a sustainability threshold, a limit of 8 tons per person and year has been proposed by Lettenmaier (2018). If applied to the global consumption levels, Lettenmaier’s threshold has been exceeded by a factor of 1.53 (Lettenmaier, 2018; UN, 2019b).

1.2 Energy Production and Sustainable Development

Moving on from the global sustainability challenges, this chapter examines the role of energy production systems in measures towards sustainable development. To understand this topic, it is helpful to consider some basic facts about humanity’s relationship with technology. The purpose of the first subchapter is to point out the extent to which the developmental lineages of humans and their tools are

intermingled. To this end, the term tool is defined broadly, so as to include any (nonhuman) object that has been built or repurposed to serve a human function. Following this logic, energy production systems are defined as tools, or sets of tools, that can be used to power other tools, such as water wheels, power plants or large domesticated animals.

1.2.1 Tools and Energy

Figure 1.4. Illustration of Mousterian era stone tools.

Above all, humans are tool-makers. The history of technology stretches back to the Paleolithic Age, when hominids began fashioning rocks into hammers and knives (Harmand et al., 2015). Since then, people have come up with increasingly

sophisticated ways of transforming natural resources into usable objects. Inventions like clothing, carrying sacks and controlled fire are what allowed humanity to migrate across the globe and adapt to new environments, far removed from its ancestral conditions. Our survival is and has been so contingent on technology that tool-making must be considered our fundamental evolutionary niche (see McNeil, 2002; Deutsch, 2011). Some scholars go even further, and suggest that we may have coevolved with the technology of our forebears (e.g., Taylor, 2010). Whether or

(15)

not this is the case, humanity’s tool-making skills have now advanced to the point that we build temporary homes in space.

Although different in form and function, all tools have one thing in common; they require an input of energy to work. Old technologies like slingshots and spears are powered by muscle contractions, which convert the chemical energy that is stored in myocytes into purposeful motion. Modern tools however, such as cars, stoves and cell phones, require more than muscle power to work. They rely on a special class of tools that are referred to herein as energy production systems (EPS). EPS convert forms of energy that are found in nature, such as the electromagnetic energy of sunlight, the chemical energy in coal and oil, and the kinetic energy of water and wind flows, into forms of energy that can be used to operate other tools. During pre-modern times, horses, oxen and water wheels served as EPS, which powered carriages, carts, plows and mills. Today, these devices have been replaced by planes, cars, tractors and industrial grinders, which are fueled by newer and more efficient EPS, such as oil refineries, wind farms and nuclear power plants (GEA, 2012; McNeil, 2002).

1.2.2 Energy and Socio-Economic Development

Considering humanity’s fundamental dependence on technology, it is easy to see why energy production systems are necessary for socio-economic progress. Modern energy systems fuel the technologies that underpin economic growth, and are prerequisite for social necessities such as heating, refrigeration, ventilation and electric light (UNDP, 2000; GEA, 2012). Furthermore, they allow for digital information services, which dramatically lower the cost of communication and give people a means to cooperate, innovate and share their ideas on a global scale, as well as to organize around political issues and common ideals (e.g., Ahmad et al., 2019). The invention of the internet has had such profound implications that historians call it a third Information Revolution2_{(Dewar, 1998). For all these reasons, providing}

access to reliable, safe and affordable energy systems is an essential step in lifting people out of poverty and creating peaceful, stable societies (UNDP, 2000; UN, 2015).

In the last two hundred years, humanity’s energy use has increased by a factor of 27 (Ritchie & Roser, 2018). However, there is great inequality between industrialized and developing nations, both in terms of their energy usage and their means of production: At present, 3 billion people burn wood, coal or garbage in order to cook and to heat their homes. Resultantly, indoor air pollution contributes to the deaths of 1.6 million people every year, most of whom are women and children in 2_{The first and second being the inventions of writing and the printing press.}

(16)

poor nations. About a seventh of the world’s population live without access to electricity. This prevents them from using modern tools for harvesting, manufacturing, agriculture, communication and data processing. With no

dependable light source, children have a hard time studying at night, and the lack of refrigeration makes it impossible to store important goods, such as perishable foods, vaccines, insulins and liquid antibiotics (GEA, 2012; Ritchie & Roser, 2019b, 2019c). Furthermore, the absence of labor saving devices like stoves, vacuum cleaners and washing machines contributes to the confinement of women children to unpaid domestic labor (Greenwood et al., 2005; UNDP, 2000).

Aside from their obvious benefits, EPS incur social costs as well, mainly related to air pollution. The combustion of biomass and fossil fuels release harmful pollutants such as carbon monoxide, nitrogen oxides and particulates. The most problematic substances and their health effects are listed in Table 1.1 below.

Table 1.1. Pollutants released from the combustion of fossil fuels and biomass, and their health effects. Adapted from Smith et al. (2013), Hydén (2008) and EPA (2019).

Particulates (PM10, PM2.5)

Causes irritation and inflammation of the lungs and airways, lowered mucociliary clearance, suppression of immune system responses to infections and inflammations, as well as an increased risk of cardiovascular diseases.

Carbon monoxide (CO)

Binds to hemoglobin and hinders the blood’s delivery of oxygen to bodily tissues. Carbon monoxide poisoning can be fatal. Early symptoms include irritability, tiredness and concentration difficulties.

Nitrogen oxides (NOx)

Causes irritation of the airways, eyes and nose, lowered lung capacity and an increased sensitivity to infections of the respiratory system.

Ozone (O3)

Produced by photochemical reactions in the troposphere, involving volatile organic compounds and nitrogen oxides. Causes severe irritation of the respiratory system and lung damage.

Sulfur dioxide (SO2) Causes irritation of the lungs and airways. Volatile Organic Compounds (VOC)

Formaldehyde Benzene Acetaldehyde Phenols Pyrene Benzopyrene Cresols

May cause cancer, as well as nerve, kidney and liver damage. Provokes allergic reactions, irritation of the lungs and airways, and lowered mucociliary clearance. Symptoms of prolonged exposure include irritability, nausea, tiredness, dizziness and breathing difficulties.

(17)

According to Cohen et al. (2017), air pollution accounts for 3.2% of the global burden of disease, and it is implicated in the deaths of nearly 5 million people every year (Ritchie & Roser, 2019c). Making a complete inventory of the social costs of modern EPS is impossible, since many of their impacts are hard to quantify, or difficult to attribute to specific energy sources. While major disasters, such as dam failures or oil spills, can have severe and long-lasting effects, it is often problematic to ascertain whether they were caused by some context-specific issue, or by an inherent risk in the technology itself (Smith et al., 2013). In summation, even though EPS are fundamental for socio-economic progress, it is important not to lose sight of their social costs.

1.2.3 The Ecological Impacts of Energy Production

At present, coal, peat, shale, oil and natural gas make up 81% of the global energy supply (IEA, 2019), and the energy sector emits about 36 billion tons of greenhouse gases (GHG) every year. This makes it responsible for 73% of all anthropogenic emissions worldwide (Table 1.2).

Table 1.2. Global anthropogenic GHG-emissions by sector and energy sub-sectors in the year 2016 (Climate Watch, 2019; using data from CAIT Country Greenhouse Gas Emissions Record, FAOSTAT Emissions Database and IEA, 2016).

Sector Waste Industry FOLUI _Agriculture _EnergyII

Gton CO2eq 1.6 2.8 3.2 5.8 36

Share of total emissions 3% 6% 6% 12% 73%

I_{Forestry and other land-use changes.}

II_{Electricity and heat (42%), transportation (22%), construction and manufacturing (17%), fugitive emissions} (8%), building (8%) and other fuel combustion (4%).

While the global GHG-releases have been rising steadily since the Industrial Revolution, the last five decades have seen a sharp increase in the emissions rate: Between the years 1970 and 2010, the cumulative amount of CO2 released to the

atmosphere has more than doubled, going from 910 billion tons to roughly 2 trillion tons. According to Edenhofer et al. (2014), the burning of fossil fuels, together with industrial processes such as flaring and cement production is behind 78% of the increase. Given the importance of energy production for socio-economic progress, as well as the risks associated with continued global warming, transitioning from fossil based energy systems to low carbon alternatives is a crucial step in sustainable development.

(18)

Like with their social costs, the innumerable points of contact between modern EPS and the biosphere makes it difficult to determine their overall ecological impacts. For instance, the harvesting of coal and natural gas releases methane (CH4) into the

atmosphere, and the extraction of petroleum leaks oil into the world’s oceans. Besides carbon dioxide, fossil fuel combustion emits nitrogen oxides (NOx) and

sulfur dioxide (SO2), which produce nitric and sulfuric acids when they are

dissolved in water. Cars, ships and fossil-based thermal plants spread a host of toxic and reactive elements, such as particulates, cadmium, lead and mercury (UNDP, 2000; Middleton, 2013). Like greenhouse gases, particulates affect climate regulation, but they also disrupt precipitation patterns and may stunt or kill many species of plants, by blocking out the sunlight or clogging up the stomatal openings of their leaves and needles (Chung & Soden, 2017; Rahul & Jain, 2014). Moreover, the land-take requirements of EPS are becoming a substantial ecological problem. According to Trainor et al. (2016), energy sprawl is now the biggest driver of land-use change in the United States. If the country is to meet its future energy demands, they estimate that 200 000 km2_{of unused land will be impacted by energy}

developments in the next twenty years, and if the spacing requirements of certain technologies are included in the calculations, the affected area grows to 800 000 km2

(Trainor et al., 2016). The spread of built environments, including buildings, roads and energy infrastructure, puts tremendous stress on the biosphere. As stated in Chapter 1.2.2, land use change has been recognized as one of the main drivers of biodiversity loss, which threatens not only ecological values, but life-sustaining ecosystem services as well.

Lastly, it is important to note that every power source has specific benefits and disadvantages. Hydropower is a good example; although it emits small amounts of greenhouse gases, it causes considerable and often irreversible damage to the local environment (Moran et al., 2018). To ascertain the ecological impacts of an EPS, its whole life cycle should be considered, from the harvesting and enrichment of raw materials and fuels, to manufacturing, transportation, installation, maintenance, decommissioning and waste management. Each step in the chain requires an investment of materials and energy, and will incur social and ecological costs (Mälkki & Alanne, 2017).

1.3 The Importance of Electricity

As suggested in Chapter 1.2.2, electricity has a number of advantages that other energy carriers lack. It is clean and safe at the point of use, and it is the primary energy source for many technologies that drive economic growth (e.g., Mahfoudh & Amar, 2014; Chapter 1.2.2). Besides its socio-economic benefits, it is also essential for solving the world’s ecological sustainability problems. As stated, it is practically

(19)

emissions-free at the point of use, which means that if it is generated by climate friendly means and then used to replace fossil fuels, it can drastically reduce the carbon footprint of technologies where such a transition is possible. Electric vehicles (EV’s) are a good example: In Sweden, where 80% of the electric supply comes from low emissions sources (Table 1.3), a typical consumer EV emits 84% percent less CO2eq than a fuel-efficient diesel vehicle of the same size. In Poland, where

most of the electricity is generated by coal-fired plants, the EV still has lower emissions than its diesel counterpart, but the difference is less significant (Messiage, 2014).

Table 1.3. Life cycle greenhouse gas emissions of nordic electricity generation systems, and their share of the Swedish electricity mix (Gode et al., 2011; SCB, 2018).

Power source gCO2eq/kWh Share of the electricity mix

Nuclear 3.5 39.3% Hydro 4.5 40.3% Wind 13 11.0% Solar N/A 0.1% Coal 759 9.3% Oil 571 Peat 862 Natural gas 747 Waste 222 Other N/A

Unlike trains and trams, which began shifting from coal powered engines to electric ones in the 1880’s, only 1% of the global car fleet is currently made up by EV’s (McNeil, 2002; IEA, 2019a). Alongside the continued development of smarter and more energy efficient tools, a gradual electrification of fossil-fueled technologies is crucial for mitigating the climate impacts of modern societies (Willliams et al., 2012).

Another benefit of electronics is the potential to dematerialize goods and services. Dematerialization refers to when a tool or a service is redesigned in such a way that it can be provided using less physical resources (Shao & Rao, 2018). Thus, its function is preserved (or improved), while its ecological costs are reduced. Electronics can contribute to such processes in part by allowing new and more efficient designs, and in part by lumping a host of tools together in multifunctional

(20)

devices, such as modern phones and computers. For example, a single smartphone, connected to a network of servers, cell towers and satellites, can continuously provide the functions of books, records, movies and magazines, watches, cameras, maps, radios, compasses, dictaphones, calculators, flashlights, thermometers, gaming devices, answering machines, and of course, stationary phones.

Additionally, information technology allows for the development of eco-friendly business practices, such as various business as-a-service models (e.g., Laine et al., 2018).

Dematerialization is often discussed together with eco-economic decoupling: Eco-economic decoupling refers to the idea that dematerialization and changing

consumption patterns could allow for increased economic growth without a related increase in the use of physical resources. Some scholars and experts argue that eco-economic decoupling has already occurred in a number of nations and markets (e.g., Godall, 2011; Ausubel & Waggoner, 2008; Sun & Meristo, 1999), while others maintain that it is too early to draw such conclusions (e.g., Steinberger et al., 2013; Shao & Rao, 2018). In any case, it is undeniable that electronics offers the potential to dematerialize many goods and services, but also that whether or not absolute dematerialization takes place depends on many additional variables, such as overall consumer behaviors and potential rebound effects, as well as the manufacturing methods, durability and recyclability of the devices in question (McCulley, 2014).

(21)

1.4 Summary of Chapters 1.1 to 1.3

The history of technology stretches back to the Paleolithic Age, when hominids first began fashioning rocks into hammers and knives. As homo sapiens emerged roughly 3 million years later, it had evolved in tandem with the development of newer and better tools. From then on, humanity’s survival has been so contingent on

technology that tool-making must be considered our fundamental evolutionary niche. Whatever approach one takes to explaining the evolution of human societies, the resulting narrative will describe the development of new technologies, either directly or indirectly. Inventions like clothes, carrying sacks and controlled fire are what allowed us to migrate out of the Great Rift Valley and adapt to new

environments, far removed from our ancestral conditions. Today, humanity’s tool-making skills have progressed to the point that we can build temporary homes in space. While different in form and function, all tools have one thing in common: they require an input of energy to work. Old technologies like spears and

hammerstones were powered by muscle contractions. Newer tools, such as stoves, cars and communication satellites, require more than muscle power to work. These depend on energy production systems (EPS). During the industrial revolution, a wealth of new tools and EPS were invented, which allowed for tremendous

increases in human health and well-being. The steam engine, the generator and the combustion engine, together with industrialized factory processes and the use of fossil fuels, catapulted humanity into an unprecedented era of socio-economic progress. In the last two hundred years, the global GDP has increased by an order of magnitude and the average life expectancy more than doubled. The global illiteracy rates have fallen sharply, as have the rates of child mortality, gender inequality, poverty and famine. Today, more than half of the world’s population live in democracies, compared to only 1% in the year 1800. However, many of our advances have incurred substantial socio-ecological costs. Anthropogenic global warming, the spread of built environments and humanity’s rampant consumption of natural resources, as well as land, water and airborne pollution, have all reached a point where they are threatening to destabilize both biospheric and human

communities. To continue making progress, we must find ways of moving towards greener, leaner and more energy-efficient economies. By replacing fossil fuels and aiding in the dematerialization of goods and services, electric energy production systems in the low emissions range can play a key role in such a transition.

(22)

1.5 Nuclear, Wind and Solar Power

This chapter gives a short historical and technological description of nuclear, wind and solar power.

1.5.1 Nuclear Power

In 1934, the Italian physicist Enrico Fermi conducted a series of experiments where he bombarded uranium with slow-moving neutrons. To his surprise, the procedure did not yield heavier elements, but much lighter ones instead. Fermi had

unwittingly become the first scientist to split the atom. In the following years, his work was replicated and expanded by Otto Hahn and Fritz Strassmann. Before publishing their results, they consulted with the Austrian-Swedish physicist Lise Meitner. As she calculated the weight of the products in Hahn’s and Strassman's experiments, Meitner realized that a portion of the uranium's mass had been converted into energy, thus providing the first experimental proof of Albert Einstein’s theory of special relativity3_{. Soon, many prominent physicists were}

attracted to the field of nuclear energy. In 1939, Niels Bohr and Fermi discussed the feasibility of a controlled fission chain-reaction, and only three years later, Fermi led a team of American scientists in constructing the world’s first nuclear reactor; the Chicago Pile-1. The reactor was built as part of the Manhattan Project, which conducted nuclear weapons research during World War II (DOE, 1994). The intertwined origins of nuclear power and nuclear weapons, and its implications for the safety of present day nuclear power plants, is discussed in Chapter 3.1.2. After the war ended, nuclear scientists turned instead towards utilizing fission energy for electricity production. Today, nuclear power accounts for 1.7% of the world’s primary energy consumption and 10% of the global electricity supply (Richie & Roser, 2018; IAEA, n.d.b.). There are currently 442 reactors in operation, dispersed over 30 countries (IAEA, 2020, 2020a).

Nuclear power plants generate electricity with the help of a tightly managed fission chain-reaction: Inside the reactor core, fuel rods containing a fissile material are hit by free-moving neutrons. As the neutrons collide with the atomic nuclei of the fuel, the atoms split into lighter elements, giving off additional free neutrons. A fraction of these neutrons goes on to split more atoms, and initiates a chain-reaction. The speed of the free neutrons is slowed by a moderating substance, such as water, deuterium oxide or graphite, and the rate of the reaction is regulated with

3_{Einstein’s most famous equation, E=mc}2, states that energy equals mass multiplied by the speed of light

squared. This implies that mass and energy are interchangeable, and that under the right conditions, one could be transformed into the other.

(23)

absorbing control rods which can be lowered into the core. Nuclear fission generates vast amounts of heat, mostly due to the kinetic energy of the product particles, but also due to the release of electromagnetic energy in the form of gamma rays. In a typical nuclear power plant, the heat is removed from the reactor by a circulating coolant fluid, which is then used to boil water into steam. The steam powers a turbine connected to a generator, and so electricity is produced (NEA, 2012).

Figure 1.5. Nuclear power plant.

The majority of the world’s nuclear power plants have Pressurized Light-Water Reactors (PWR). A PWR uses water, both as its neutron-moderator and as its coolant fluid. The next most common reactor is the Boiling Light-Water Reactor (BWR). The main difference between the BWR and the PWR, is that the former produces steam directly in the reactor core. The third most common type is the Pressurized Heavy-Water Reactor (PHWR), which uses deuterium oxide as its coolant and neutron-moderator (NEA, 2012). Roughly 68% of the operational reactors are PWR’s, while BWR’s and PHWR’s account for 26% of the remaining fleet. Besides these, there is a small number of graphite moderated and gas-cooled reactors in operation, as well as three Fast Breeder Reactors (FBR) (IAEA, 2020). The typical lifespan of a commercial nuclear plant is 60 years and the primary fuel materials are uranium (235_{U), and to a lesser extent plutonium (}239_{Pu). Most civil}

nuclear reactors burn enriched uranium, which consists of natural uranium that has been gasified and processed to increase its percent composition of 235_{U. The}235

U-grade in the finalized product is usually at or below 5%. This level of enrichment is significantly lower than that of weapons-grade uranium, which has a 235_{U-content of}

(24)

90% or above. After the enrichment process, the gas is converted into uranium dioxide (UO2), which is pressed into pellets and placed in the fuel rod assemblies.

Plutonium is nearly non-existent in nature, but can be extracted from spent nuclear fuels in the reprocessing stages of the fuel cycle (NEA, 2012; Ganguli, 2001; Schlömer et al., 2014). Additional fuel related questions, such as the status of the world’s uranium reserves, are discussed in Chapter 3.1.1.

1.5.2 Wind Power

As early as 6000 BCE, the Mesopotamians began using sails to propel their boats on the Euphrates and Tigris rivers (Potts, 2012). In the following millennia, people continued to harness wind energy to power important tools, such as mills, grinders, water pumps and saws (McNeil, 2002). The first instance of wind being used to produce electricity came in 1887, when the scottish professor James Blyth built a large turbine in the garden of his holiday home (Price, 2005). Today, the wind power sector is growing rapidly, and accounts for 0.8% of the world’s primary energy consumption, as well as 4% of the global electricity production (Ritchie & Roser, 2018; IAEA, n.d.b.).

A commercial wind turbine typically consists of 2-3 rotor blades, attached to a nacelle on top of a tall tower. Inside the nacelle, the motion of the blades is carried to a gearbox, which in turn drives a generator. This way, the wind’s kinetic energy is converted into mechanical work, and the work into electricity. There are two main types of wind turbines; horizontal-axis turbines and vertical-axis turbines (Figure 1.8). X-axis turbines are constructed so that the rotors get turned towards the wind. This feature is not necessary in y-axis turbines, whose blades are

omnidirectional (DOE, n.d.).

(25)

Wind turbines come in a range of sizes and they can be installed either on land or in large bodies of water. The most cost-effective solution is to group many turbines together in wind farms, either on- or offshore. Offshore farms allow for the use of massive turbines, but they are generally more expensive to maintain. The typical lifespan of a commercial turbine is 25 years (DOE, n.d.; Schlömer et al., 2014).

1.5.3 Solar Power

The history of solar power begins with Alexandre E. Becquerel’s discovery of the photovoltaic effect in 1839. Experimenting in his father's laboratory, Becquerel submerged platinum sheets in a silver chloride acid solution. He observed that when the cell was illuminated, an electric current was generated across the plates. 38 years later, William G. Adams and Richard E. Day established that sunlight can generate an electrical current in solidified selenium, and in 1883, Charles Fritts built the world’s first solid-state photovoltaic cell, comprised of a wide copper plate, coated in selenium with a gold layer on top. By this time, the fact that sunlight could be converted into electricity had been well established. However, no one properly understood the underlying mechanisms at work. This changed in 1905, when Albert Einstein published his Nobel Prize-winning paper explaining the photoelectric effect (Fraas, 2014): Einstein postulated that light, which had been described by Newton as consisting of particles, and by Hooke and Maxwell as consisting of waves, can be thought of as both particles and waves. More precisely, he suggested that light is made up of waves that travel as wave-packets, or “quanta”. In modern parlance, quanta of light are usually referred to as photons. One crucial point in Einstein’s theory is that the energy of a photon is proportional to its oscillation frequency. When a photon of sufficient energy collides with an atom-bound electron, it transfers some of its energy to the electron, potentially making it jump to a higher orbital shell. If the energy transfer is large enough, the electron will escape the pull of the nucleus, leaving an electron hole in the host atom (Einstein, 1905). In the photoelectric effect, electrons are ejected into the surrounding space, whereas in the photovoltaic effect, electrons are ejected into a conductive material and become part of an electrical current (Jäger et al., 2014).

At present, solar power accounts for roughly 0.4% of the world’s primary energy consumption and 1% of the global electricity production (Ritchie & Roser, 2018; IAEA, n.d.b.). Modern solar cells typically use crystalline silicon (c-Si) as their photoelectric material (IRENA, 2016). A c-Si cell consists of two layers of either mono- or multicrystalline silicon, sandwiched between two conductive materials, with a protective glass sheet on top. The silicon layers are doped, meaning that other elements have been injected in their atomic lattices, so that one contains an excess of free-moving electrons (the N-type layer), while the other contains atoms

(26)

with empty slots in their outermost valence shells (the P-type layer). Where the two layers meet, electrons from the N-type side migrate to fill the electron holes at the P-type side. This creates an electric field, which has a slight positive charge at its boundary on the N-type side and a slight negative charge at its boundary on the P-type side. When photons of sufficient energy hit the panel, electrons are ejected from their host atoms at the P/N-junction. Because of the electric field, the free electrons are pulled into the N-type layer, while the electron holes are repositioned to the P-type layer. This process creates a potential difference between the layers, and if a circuit is established between the conductive materials at the top and bottom of the cell, an electrical current will flow between them (Jäger et al., 2014). Solar panels come in many different sizes and can be placed either on ground based mounts, or on rooftops and other suitable surfaces. As with wind turbines, grouping large panels together in utility-scale solar farms is the most cost-effective solution. The average lifespan of both smaller and utility-scale panels is 25 years (Schlömer et al., 2014).

(27)

1.6 Aim and Research Questions

The aim of this thesis is to assess the sustainability of nuclear power. The assessment is performed using Multi-Criteria Analysis, where the social, economic and

ecological impacts of nuclear power are compared to those of wind and utility scale solar power. The thesis does not attempt to give prescriptive guidelines regarding the use or disuse of nuclear power. Rather, its purpose is to grow the epistemic base of sustainable energy development. The overarching research question is:

• What is the sustainability of nuclear power?

In order to structure the investigation, a number of sub-questions have been formulated:

•_{What is sustainable development?}

•_{What are the global sustainability challenges?}

• What is the role of energy production systems in measures towards sustainable development?

• What are the primary socio-ecological costs and benefits associated with modern energy production systems?

• What are the historical and technological origins of nuclear, wind and solar power?

And finally…

•_{What are the ecological, social and economic impacts of nuclear power and} how do these compare to the impacts of wind and solar power?

1.7 Delimitations

This thesis examines the sustainability of wind power, utility scale solar power and nuclear power on a global scale. The lack of a geographical boundary acts as a delimiting factor on what data is included in the assessment: National, regional or local sustainability measures are avoided, in favor of global averages. This selection criteria also serves as a partial control for context-specific confounding variables. Even though the study is grounded in the idea of sustainable development, which is a moral philosophy, the goal has been to avoid subjectivist approaches to evaluation wherever possible. Furthermore, the selection of sustainability measurements and the weighting of the impact scores have been performed in accordance with scrutinizable theories and concepts, rather than the hidden reasoning of particular stakeholders, experts or decision makers. Lastly, the thesis examines the

(28)

sustainability of wind, solar and nuclear power in their current level of technological development. This means that the potential effects of technologies that are not yet ready to be implemented are not considered.

1.8 Target Groups

The thesis is targeted towards researchers who are active in the fields of Environmental Technology, Sustainability Science and Sustainable Energy Development, as well as energy experts, policy makers and the public at large. Because of its wide scope and basic approach to the topics at hand, it could also be used as an introductory learning material for students of the Environmental Sciences.

1.9 Ethical Considerations

There are no conflicts of interest and the thesis does not handle any personal or sensitive information. As such, no special ethical considerations are necessary (SFS, 2003:460).

(29)

2 Methods and Methodology

As stated in Chapter 1.1, the concept of sustainable development includes three pillars of human progress; social, economic and ecological sustainability, as well as the generational goal, which states that measures towards sustainable development should “...[ameliorate] the needs of the present without compromising the ability of future generations to meet their own needs” (Chapter 1.1). Thus, sustainability assessments of energy production systems (EPS) should examine their social, economic and ecological impacts, both in the short- and the long-term. In performing this task, researchers often employ Life Cycle Assessments (LCA), sometimes coupled with Multi-Criteria Decision-Making analysis (MCDM) (Mälkki & Alanne, 2017; Campos-Guzman et al., 2019). As the name implies, LCA’s determine the impacts that are generated by a product or service during its entire life cycle. For an EPS, this includes the extraction and enrichment of raw materials and fuels, manufacturing, transportation, installation, maintenance,

decommissioning and waste management (Mälkki & Alanne, 2017; Gode et al., 2011). Although LCA is a leading tool for making ecological impact assessments, its formalized methodology does not include indicators of social and economic

sustainability (ISO 140400:2006). The search for a more holistic approach has led researchers to adopt the MCDM methodology (Campos-Guzman et al., 2019). MCDM analysis is a tool for resolving multiple choice situations, which may or may not include conflicting goals. As such, it provides a methodological structure where researchers can mix impact measures from disparate investigative fields. In general terms, MCDM analyses begin with the delineation of a problem and a set of choices that could resolve it. After that, evaluation criteria are chosen, along with

quantifiable indicators that determine how well the options perform according to each criterion. The indicator scores are standardized and weighted in accordance with the perceived importance of the criteria. Lastly, the scores are summed to produce a unified measure of fitness for each of the choice options. Table 2.1 gives a generic representation of an MCDM model, where A is the set of choices, C the set of evaluation criteria and c1(a1) the evaluation of option a1 according to criterion c1

(Van den Bergh, 1999):

Table 2.1. An MCDM evaluation table (adapted from Van den Bergh, 1999).

Alternatives

Criteria Unit a1 a2 a3 …

c1 . c1(a1) c1(a2) c1(a3) .

c2 . . . . .

(30)

When MCDM analysis is used in sustainability assessments, the tasks of selecting evaluation criteria and indicators, as well as developing a weighting scheme for the indicator scores, can be performed either by the researchers themselves, or by consulting experts, decision-makers or interest groups who have a stake in the examined problem (Campos-Guzman et al., 2019; Geneletti, 2019). Although the latter option is often promoted as practical, inclusive and democratic, it also makes so that the studies’ results become a function of the hidden reasoning of interview subjects and survey respondents, and thus hampers criticism.

In a review of 179 articles assessing the sustainability of EPS in the renewables sector, Campos-Guzman et al. (2019) determines that researchers who use a combination of LCA and MCDM produce stronger results than those who employ either one of the tools alone. Following their conclusions, the thesis at hand employs an MCDM model, coupled with data gathered primarily from life-cycle analyses. The selection of evaluation criteria and the weighting of the indicator scores are made with reference to scrutinizable explanatory knowledge, rather than stakeholder interviews or surveys, to avoid the epistemological pitfalls that such methods bring into the assessment. The study presents three overall sustainability scores for each of the examined technologies. Two are based on the parallel concepts of weak and hard sustainability, and the third represents a strictly anthropocentric perspective.

2.1 Literature Study

The background information and the data used in the thesis has been gathered through an extensive literature search, focused on peer reviewed and otherwise credible sources, such as highly cited governmental and intergovernmental

organizations, including the IPCC, IRENA and UNDP. A number of search engines and databases have been utilized in the search; primarily ScienceDirect, JStor, SpringerLink, SAGE Open, PLOS One, PubMed and Google Scholar. Some of the search words and phrases that have been used are; sustainable development, sustainable

energy development, LCA, Life-Cycle Assessment, MCDM, MCA, Multi-Criteria Decision-Making, nuclear power, solar power and wind power. Through critically reviewing each

source and comparing their conclusions, the thesis seeks to establish the most credible position in each of the topics covered.

2.2 Multi-Criteria Decision-Making Analysis

The present thesis examines the sustainability of nuclear power by comparing its social, economic and ecological impacts to those of wind and utility scale solar power; two energy sources that are widely recognized as sustainable (e.g., UN, 2016). The assessment is performed using MCDM analysis with a Weighted Sum

(31)

(WSM) scoring system and a Distance-To-Target (DTT) weighting scheme. This method was chosen for its mathematical simplicity, which allows for a transparent handling of the collected data.

As stated, an MCDM analysis begins with the delineation of a problem and a set of choices that could resolve it. The problem addressed in this study can be described as ‘identifying the most sustainable EPS’ out of three possible options; nuclear, wind and solar power. The second step consists of deciding on a set of evaluation criteria and associated indicators. By definition, a sustainability assessment seeks to

determine the social, economic and ecological impacts of the study object. Hence, these categories form the basic evaluation criteria in the assessment at hand. The sustainability indicators consist of life-cycle or lifetime impact measures, and all but three are related to a functional unit of 1 TWh of electricity4_{, (the exceptions are}

‘compounded downtime’, ‘toxic radioactive wastes’ and ‘EROI’). All indicators but one (EROI) reflects negative impact measures, such as greenhouse gas emissions, land-take requirements and material throughputs, and the alternative with the lowest total score is identified as the most sustainable option. The impact data has been collected from peer-reviewed or otherwise credible sources, and the authors own calculations are reported in Appendix A and throughout the results section. To apply the WSM, the indicator scores must first be converted into a common, dimensionless unit (Van den Bergh, 1999). This can be achieved by simply canceling the functional unit and impact units, and then dividing the remaining values by their sum. This operation places the indicator scores on a common, unidimensional scale, where c1(a1) + c1(a2) + …c1(an) = 1. An example calculation is given in Table 2.2

below:

Table 2.2. Example of the standardization of the indicator scores, using emissions data from Gode et al. (2011).

Power source Nuclear Wind Hydro Sum

ton CO2eq/TWh 3500 13,000 4500 21,000

↓

Standardized score 0.17 0.62 0.21 1

The converted scores retain their expression of the EPS comparative performance according to the criteria, but can now be weighted and summed to produce an overall sustainability measure. Again, since all indicators are based on (or

(32)

transformed to) negative impact scores, the alternative with the lowest total score is regarded as the most sustainable option. A generic example of the final evaluation table is given in Table 2.3 below, where the standardized results have been multiplied by 100 for increased clarity:

Table 2.3. A WSM evaluation table (adapted from Van den Bergh, 1999).

Alternatives Criteria Weight a1 a2 a3 ... c1 1.25 25 62 13 . c2 1.54 33 41 26 . c3 1.21 48 18 34 . Weighted sum 140 162 97 .

As stated, the weightings are determined by the perceived importance of the evaluation criteria. In Table 2.3 above, criteria 2 (c1) is deemed the most important

(column 2), and alternative 3 (a3) has the lowest total score (a3WSM= 97 = 1.25 ×

13 + 1.54 × 26 + 1.21 × 34), making it the most sustainable choice according to the methods of this study.

2.3 Evaluation Criteria and Indicators

This chapter explains how the basic evaluation criteria of social, economic and ecological sustainability have been narrowed down and split into quantifiable indicators.

2.3.1 Ecological Indicators

The process of selecting ecological sustainability indicators has been guided by the Planetary Boundaries concept (Rockström et al., 2009), coupled with a meta-analysis of articles on sustainable energy development by Dorning et al. (2019). The Planetary Boundaries is a conceptual framework which intends to map out a “safe operating space for humanity”, by identifying physical limits to the pressures

humanity can put on life-sustaining Earth-systems before irreversible or catastrophic damages occur. In its current instantiation, the framework includes 9 planetary boundaries, four of which are reported as crossed (Table 2.4).

(33)

Table 2.4. Planetary Boundaries (Rockström et al., 2009; Steffen et al., 2015).

Impact categories Status

1. Climate change Crossed, in the zone of uncertainty 2. Biodiversity loss Crossed, beyond the zone of uncertainty 3. Land-system change Crossed, in the zone of uncertainty 4. Freshwater use Within the safe operating space

5. Biogeochemical flows Crossed, beyond the zone of uncertainty 6. Ocean acidification Within the safe operating space

7. Atmospheric aerosol loading Unknown

8. Stratospheric ozone depletion Within the safe operating space 9. Chemical pollution Unknown

It is important to note that the Planetary Boundaries concept is based on hypotheses about the outcomes of large-scale socio-ecological systems interactions, many of which lack clear evidence (e.g., Brook, Ellis & Buettell, 2017). However, the framework is widely accepted within the Environmental Sciences, and while it may need adjustments to reach the status of theory, it can act as an actionable summary of the global environmental concerns.

Dorning et al. (2019) have reviewed 179 articles on sustainable energy

development, extracting and rank-ordering 37 environmental impact indicators based on their prevalence in the literature. These can be sorted into 6 general categories; air, land, water, waste, resource use and unspecified impacts. Table 2.5 shows the most commonly used indicators for each category, as well as their associated Planetary Boundaries:

(34)

Table 2.5. Ecological sustainability indicators and their associated Planetary Boundaries. Adapted from Dorning et al. (2019), Steffen et al. (2015) & Chapter 1.1 to 1.3.

Impact category Indicator Planetary Boundary

Air

GHG emissions _{Climate change, biodiversity loss,} ocean acidification, chemical pollution, atmospheric aerosol

loading. NOx emissions

Acidification potential Particulate emissions

Land Land-take (area) Land-system change, biodiversity loss.

Water Water consumption Freshwater use.

Resource use

Fossil fuel consumption

All nine boundaries*_. Minerals consumption

Overall resource use

Waste

Overall waste

Chemical pollution, biodiversity loss, land system change, climate change. Solid waste

Toxic and radioactive waste

Unspecified Environmental impacts All nine boundaries.

*_{All anthropogenic ecological degradation can be attributed to humanity’s use/consumption of} natural resources (see Chapter 1.1.2).

Five of the above indicators have been selected for the present study; greenhouse gas (GHG) emissions (tonCO2eq/TWh), land-take (km2/TWh), material throughput

(ton/TWh), non-recyclable waste (ton/TWh) and toxic/radioactive waste (qualitative indicator). Although solar power emits higher levels of NOx, SO2 and

VOC than wind and nuclear power, the emissions are minimal compared to those of conventional power sources such as coal and oil. (Sathaye et al., 2011). Similarly, nuclear power has a larger water consumption than wind and solar power, but the energy sectors water use is dwarfed by that of the agricultural and manufacturing sectors (Braumann et al., 2016), and Steffen et al. (2015) judges the global freshwater consumption to be well within the affected Earth-systems carrying capacity. Lastly, all of the examined technologies produce similarly low particulate emissions (Sathaye et al., 2011). As such, none of the latter issues are deemed consequential enough to be included in the assessment.

(35)

2.3.2 Social and Economic Indicators

Building on the UN Sustainable Development Goals, the economist Kate Raworth has formulated a sister framework to the Planetary Boundaries; the Oxfam

Doughnut Model of Economics. The Doughnut Model includes the Planetary Boundaries and adds 12 foundational needs for social development; food,

healthcare, education, jobs, peace and justice, a political voice, social equity, gender equality, housing, social networks, water and energy (Raworth, 2017). Like the Planetary Boundaries, Raworth’s model has not achieved the status of theory, but it can serve as an approachable overview of the necessities for social progress. Electric EPS are essential for providing most of the social needs identified in the Doughnut Model, such as jobs, food, decent healthcare, proper housing and a well-functioning educational system (see Chapter 1.2). As Chapter 1.2 shows, they can also serve an important role in the spread of democratic values and the liberation of women and children in poor nations. By virtue of being power production systems in the low emissions range, nuclear, wind and solar power all have tremendous socio-economic benefits, especially when compared to fossil-fueled alternatives (see Chapter 1.2, 1.3). Therefore, all but one of the selected sustainability indicators are focused on their undesirable impacts, with the exception being Energy Return On Energy Invested (EROI). The EROI of an EPS consists of the ratio between the useful energy it delivers over its life-cycle, and the useful energy that is expended during its construction, operation, maintenance and decommissioning. Thus, a high EROI indicates a high capacity to promote economic growth, while an EROI of 1 or lower means that the EPS has no net benefit, or that it acts as an energy sink. Besides efficient energy systems, many tools that are essential for producing economic growth, as well as the social goods identified by Raworth, depend on an

uninterrupted supply of electricity (Chapter 1.2). To reflect the need for security of supply, intermittency (compounded downtime) has been added to the

socio-economic impact measurements. The last two indicators reflect the examined technologies negative health effects (associated fatalities/TWh) and their economic costs (LCOE).

In addition to the more general problems that are addressed by the above indicators, the nuclear sector has some endemic sustainability issues that are often raised by critics of the technology; the risk of nuclear fuel depletion, the risk of catastrophic accidents and the risk of nuclear weapons proliferation. Due to their complexity, these problems have been investigated separately and are given their own chapter in the beginning of the results section, the conclusions of which are referenced

(36)

2.4 Distance-To-Target Weighting Method

As stated, when MCDM analyses are used in sustainability assessments, the

weightings of the indicator scores are often informed by surveys or interviews with decision-makers and stakeholder groups. However, this practice is questionable, since it grounds the studies’ results in hidden knowledge, and thus prevents criticism. To avoid this glitch in the study design, this thesis opts instead for a Distance-To-Target (DTT) weighting scheme:

Table 2.6. DTT Weighting Table: The ecological sustainability indicators are displayed in green and the socio-economic indicators in yellow (Steffen et al., 2015abd_{; NASA, 2020}a_;

Lettenmeier, 2018c_{; UN, 2019b, 2019c, 2019d, 2019e}cefg_{; Ritchie & Roser, 2019c}g_).

Indicators PB / UN SDG State / Target → Weight

GHG-emissions Climate change (PB1)a _{413 / 350} _1.18

Land-take Land-system change (PB3)b _{62 / 75} _1.21

Material throughput _{Global material footprint}

(SDG12)c 12.2 / 8 1.53

Non-recyclable wastes

Toxic/radioactive wastes Chemical pollution (PB9)d _N/A ₁

Indicators UN SDG Target / State → Weight

EROI Energy efficiency (SDG7)e _{2.7 / 2.3} _1.17

Intermittency _{Work and economic growth}

(SDG8)f 7 / 4.5 1.56

Economic costs

Negative health impacts Energy related fatalities (SDG3)g _{0% ← 9%} _1.09

Control Variables

a_{Atmospheric CO2 (ppm).}

b_{Global area of forested land as percentage of pre-industrial forest cover (%).} c_{Global consumption of physical resources per capita (tonnes).}

d_{No quantitative control variable or target measure have been established.} e_{Average annual rate of improvement in global energy efficiency (%).} f_{Annual growth rate in real GDP in the world’s least developed countries (%).} g_{Percentage of deaths associated with in- and outdoor air pollution (%).}

With a DTT weighting scheme, the importance of the indicators is derived by measuring the distance between an associated situation in the world and a preferred

(37)

goal state. Thus, the weighting factors consist of the ratio between an impact-related state and a target state, as defined by some scientific theory, concept or political policy (Castellani, Benini, Sala & Pant, 2016). This method allows researchers to ground their decisions in scrutinizable explanatory knowledge, rather than the hidden reasoning of survey respondents and interview subjects. In this study, the weights for the ecological and socio-economic indicators are derived from goal states and impact thresholds identified in the Planetary Boundaries (PB) framework and the UN Sustainable Development Goals (SDG). Table 2.6 above displays the selected indicators and their associated PB’s or SDG’s, as well as the control variables used and the resultant weighting factors.

2.5 Weighting the Evaluation Criteria

In addition to weighting the indicator scores, the comparative importance of the evaluation criteria must also be established (Van den Berg, 1999):

Table 2.7. Weighting of the evaluation criteria.

Weak Sustainability Score Hard Sustainability Score Anthropocentric Score

↓ ↓ ↓

Weight Evaluation Weight Evaluation Weight Evaluation

×1 Ecological ×2 Ecological ×1 Ecological

+ + +

×1 Socio-economic ×1 Socio-economic ×2 Socio-economic

As Table 2.7 shows, this thesis groups the indicators into two sets; one consisting of the ecological impact measures (displayed in green), and a second consisting of the social and economic impact measures (displayed in yellow)5_{. During the final stage}

of the assessment, three overall sustainability scores are calculated for the examined technologies: In the first, the set scores are summed, standardized and then added 5_{There are three basic evaluation criteria; ecological, economic and social sustainability. However, because} global increases in human well-being are so tightly correlated with economic development (see Chapter 1.1.1), grouping the social and economic indicators into a shared set is deemed logically defensible in the context of this study.

(38)

together. This means that the ecological and socio-economic dimensions of the assessment are treated as equally important. This can be regarded as a weak

sustainability measure, where natural and socio-economic capital is treated as

interchangeable (Ammenberg, 2012). The second score has a weighting factor of 2 applied to the ecological indicators, thus treating the environmental impacts as twice as important as the socio-economic ones. This is meant to produce a hard

sustainability measure, grounded in the idea that protecting the integrity of resource

producing Earth-systems is a fundamental prerequisite for social and economic value creation (Daly, 1991; Ammenberg, 2012). The third score applies the same

weighting factor to the socio-economic indicators instead, thus producing an anthropocentric score, where human values are treated as twice as important.