Nuclear Economy 2 E-Book
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- Herausgeber: John Wiley & Sons
- Kategorie: Wissenschaft und neue Technologien
- Sprache: Englisch
This book presents the factual, precise, complete and accessible economic elements of nuclear energy in order to contribute to an informed and dispassionate debate. It analyzes the economic aspects of spent fuel management, including the costs and financing of long-term storage and deep geological disposal. The economic costs of a nuclear accident are also discussed from both theoretical and applied angles, based on the Fukushima nuclear disaster. Nuclear Economy 2 also examines the industrial and political aspects of the future energy mix. Nuclear energy is thus placed in the more global context of the European electricity market. Finally, this book offers a panorama of energy scenarios on the scale of France, but also of the world.
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Seitenzahl: 435
Veröffentlichungsjahr: 2023
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SCIENCES
Energy, Field Directors – Alain Dollet and Pascal Brault
Nuclear Energy, Subject Head – Sylvain David
Nuclear Economy 2
Nuclear Issues in the Energy Transition
Coordinated by
Jacques Percebois
Nicolas Thiollière
First published 2023 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.
Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:
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© ISTE Ltd 2023The rights of Jacques Percebois and Nicolas Thiollière to be identified as the authors of this work have been asserted by them in accordance with the Copyright, Designs and Patents Act 1988.
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Library of Congress Control Number: 2023931851
British Library Cataloguing-in-Publication DataA CIP record for this book is available from the British LibraryISBN 978-1-78945-095-8
ERC code:PE2 Fundamental Constituents of Matter PE2_3 Nuclear physicsPE8 Products and Processes Engineering PE8_6 Energy processes engineeringSH1 Individuals, Markets and Organisations SH1_12 Agricultural economics; energy economics; environmental economics
1Management of Spent Fuels
Jacques CANTARELLA1, Cécile EVANS2, Pierre KUNSCH1,3, Didier LÉONARD1and Jean-Paul MINON1
1ONDRAF, Brussels, Belgium
2Orano, Châtillon, France
3École polytechnique de Bruxelles, Brussels, Belgium
1.1. Spent fuel management strategies and costs
One of the main issues influencing the decisions made regarding the use of nuclear energy concerns the management of spent fuels, containing both highly radioactive waste and recoverable nuclear materials (namely fissile uranium and plutonium). The spent fuel management technologies that are used must meet the following requirements: guaranteeing the fundamental safety objective of protecting people and the environment from the dangers of radiation, ensure compliance with guarantees against nuclear proliferation and the safety of nuclear materials, and maintaining the economic aspects of nuclear energy.
Since commercial nuclear energy operations first came into existence about 70 years ago, the nuclear sector has taken a responsible approach to the entire lifecycle of spent fuels. For several decades, some countries have been applying the principles of circular economies through the recycling of spent fuel and through minimizing waste. In other countries, the effective implementation of safe surface storage solutions has provided the time needed to develop robust technical solutions, as well as a democratic and transparent decision-making process for the final storage of high radioactivity waste. In any case, the final storage of highly radioactive waste is an issue that requires close attention. There is a widespread belief today, grounded in scientific study, that the removal of high-level waste (HLW) from the human environment through storage in deep geological repositories is both safe and environmentally friendly, and that the science and technology behind this practice are well developed. However, no deep geological repositories are operational in the world at this time.
Figure 1.1.Requirements and large cycle options presented in IAEA (2018).
1.1.1. The different options of the cycle
The different options of the cycle offer a different status to the spent fuel:
the fuel in its entirety is considered to be waste, and as such must be packaged and isolated in deep storage;
the fuel is recycled in the water reactors in order to use the small amount of remaining fissile material;
the fuel is recycled several times in Generation IV breeder reactors to convert and use the large remaining amount of fertile materials.
These three primary options show the progress both in terms of the circular economy, but also in terms of minimizing the amount of highly radioactive waste to be managed over the very long-term (OECD/NEA 2006, 2021) as illustrated by Figure 1.1.
1.1.1.1. The open cycle
The open cycle (see Figure 1.2) is the fuel cycle currently considered as the reference option in a number of nuclear-powered countries. It is based on thermal neutron reactors.
The spent fuels are stored safely, waiting to be placed in a deep geological repository. The surface storage of the fuels can take place on the reactor site and/or on a dedicated centralized site. The spent fuels will be transported to the packaging site in waste packages compatible with the requirements of the deep storage infrastructure. The spent fuels do not undergo chemical treatment since they are considered to be fully composed of highly radioactive waste.
Figure 1.2.Illustration of an open nuclear cycle.
1.1.1.2. Monorecycling in a light water reactor
The process of monorecycling in a light water reactor (see Figure 1.3) has been implemented for several decades in France, as well as in a number of other European countries, Russia and Japan, and has now gained benefits from significant industrial experience. It is currently being implemented in China with the planned development of recycling capacities. The recycling facilities of Orano de La Hague and Melox have processed more than 37,500 tHM (metric tons of heavy metals) of spent fuels discharged from French and foreign reactors, and manufactured 2,900 tHM of MOX fuels loaded in more than 40 light water reactors, and are considered to be state of the art at the global level. This option is the first step to progressing toward more advanced options for the multi-recycling of fuels in light water reactors through the use of fuel technologies in development of the MOX2 or Remix type, and/or toward the closure of the cycle through the use of fast neutron reactors.
Figure 1.3.Illustration of a nuclear cycle with mono-recycling in a light water reactor.
Figure 1.4.Illustration of a nuclear cycle with multi-recycling in a light water reactor.
Figure 1.3 illustrates the processes involved. The cooled spent fuel is chemically separated (reprocessed), and the uranium and the plutonium for reprocessing are recovered to be reused in the form of new fuels; the minor actinides and fission products constituting the “high-level waste” are packaged in the form of a glazed, solid and stable matrix inside stainless steel containers. The vitrified packages are stored while waiting to be placed in a deep geological repository. The volume of this waste is less than the volume of spent fuel from the open cycle (by a factor of 5). The metal structures of the fuel are compacted and also packaged in stainless steel containers, constituting medium radioactivity waste which can generally be disposed of safely in properly designed medium radioactivity waste depots, in accordance with national regulations.
Plutonium mixed with depleted uranium is used to make mixed oxide fuel (MOX), which is refilled in reactors. The recycling of plutonium makes it possible to use the content of the fissile materials of plutonium (about 60%) in the fuel. The uranium separated during reprocessing can be re-enriched to make a new fuel. The reprocessed uranium is only slightly radioactive; it can be preserved as a future resource. If it is considered a waste, it can be stored in a way that is similar to long-lived low-level waste (LLW) in accordance with current national legislation. This fuel cycle, qualified as mono recycling, requires only about 75% of the natural uranium necessary for the open cycle due to the reuse of the fissile isotopes uranium and plutonium. An evolution toward a multi-recycling cycle in a light water reactor can be projected (see Figure 1.4), pending the deployment of fast reactors. In this sense, France is currently conducting a research and development program on MOX2 fuel technologies with objectives of stabilizing spent fuel and plutonium inventories.
1.1.1.3. Multi-recycling in a fast neutron reactor
Multi-recycling in a fast neutron reactor (see Figure 1.5) has not yet been implemented on an industrial scale and continues to be the subject of research and development in many countries, as well as within the framework of multinational collaborations. As the name suggests, this fuel cycle is similar to the fuel cycle with multi-recycling in a water reactor described above, except that the fuel is recycled several times in fast neutron reactors. In order to have sufficient fissile materials for very long-term multi-recycling, a fast neutron reactor is used. This type of reactor uses neutrons at higher energies, resulting in an increase in the plutonium generated from the fertile uranium. Approximately the same amount of plutonium is obtained from the spent fuel as in the fresh fuel, or even more plutonium when used in the breeder mode. The minor actinides and the fission products produced during each cycle must be separated and packaged in waste packages, in a similar way to the recycling cycle in a water reactor.
Figure 1.5.Illustration of a nuclear cycle with multi-recycling in a fast neutron reactor.
In a fast neutron reactor, the conversion of fertile uranium into fissile plutonium is very high in comparison with a thermal reactor. This implies a sharp reduction in the amount of natural uranium necessary for the production of a unit of energy.
Fast reactors can recycle the plutonium they produce or plutonium produced by water reactors indefinitely, including that of MOX or MOX2 light water reactor fuels, thus making the most of their energy potential while avoiding the long-term storage of spent fuel that contains valuable materials.
Advanced options can also transmute minor actinides (in particular neptunium, americium and curium) in order to further reduce the amount of HLW, as well as the duration for which they will remain hazardous. These options are under development and require additional technologies during the flow separation step, and for the manufacturing step of the fuel. Fuels containing minor actinides are highly radioactive and must be manufactured remotely in specially shielded “hot cells”. To obtain a sufficient transmutation of minor actinides and potentially long-lived fission products, different systems may be called for, such as sodium fast neutron reactors, molten salt fast neutron reactors, or possibly accelerator-controlled subcritical reactors (referred to as ADS, which stands for accelerator-driven system).
In the case of molten salt reactors, the fuel is liquid, so the requirements of the recycling system are different from other systems operating with solid fuels. We can note a recent revival of interest in research on the transmutation separation with the objective of reducing the amount of radioactive waste, its residual heat and its long-term radiotoxicity, and consequently, the need for deep storage infrastructures is reduced (OECD/NEA 2011). However, this additional step, now in the initial R&D phase, will require dedicated cycle infrastructures and adds additional expenses.
1.1.2. Characteristics of the cycle options
The management of spent fuels is a major financial issue that requires long-term strategic planning. Today, most countries have set up financing mechanisms to generate funds for this purpose.
The construction and operation of the geological storage facility represent significant costs that usually occur decades after the energy is produced (see section 1.2). The identification of the appropriate geological conditions and the necessary surface area is particularly important in the case of an open cycle, though it is necessary for all options. The importance of such conditions is reduced by partial or complete recycling. The reprocessing and reuse of nuclear materials in reactors reduces the volume, long-term radiotoxicity and thermal waste. If the minor actinides are recycled and consumed, the long-term effects on the performance of deep geological storages will be further improved.
In the case of open cycles, as a result of unforeseen delays in the commissioning of the deep storage, the spent fuel may remain in a stockpile at the reactor sites for much longer periods than initially anticipated, even after the shutdown of the reactors and the dismantling of the required fuel handling facilities. This can add costs and require new installations to handle the packaging and ensure the reconditioning of the fuel during long-term maintenance and for packaging in waste packages and depositing once the deep storage is operational.
Monorecycling requires the construction and operation of MOX fuel recycling and manufacturing facilities. Since these costs are incurred at the same time as energy production, large upfront payments are necessary. For countries with limited installed nuclear capacity, the use of contracts for services offered by the owners of existing recycling capacities has been practiced for decades, and today it is offered in France and Russia.
The options for multi-recycling with fast neutron reactors require investments in recycling facilities and higher reactor costs for fast reactors compared to thermal reactors. Both are upfront costs. Significant cost savings for deep storage can be achieved given the considerable reduction it provides in thermal power, volume and the radiotoxicity of waste.
Economies of scale can be an important factor for countries with low installed nuclear capacity and newcomers. The sharing of infrastructure downstream of the cycle, especially for recycling requiring significant investments, is a way to significantly reduce the financial burden.
Regardless of the cycle option chosen, the financial needs must cover all operations for the complete management of spent fuel up to the storage of radioactive waste, and even beyond the closure of the deep storage. The financial needs to be covered in the management of spent fuels must take into account the overall approach, including both the short-term stages as well as the very long-term duration of the entire system or program. These options have different spending profiles and also different risks and uncertainties that will change over time. The open cycle has lower short-term costs, but the uncertainties and risks associated with the changes increase over time. Recycling and cycle closure options have higher short- or medium-term costs. However, their durability characteristics, which include in particular the optimization of waste packages for surface storage, transport, and storage, limit the operations for preparation and deep storage, thus reducing future uncertainties.
The monorecycling of the fuel allows the manufacture of fuels with plutonium or uranium for reprocessing, which allows for savings of about 25% of the natural uranium. In a multi-recycling scenario, in addition to an initial inventory of fissile materials, depleted uranium stocks provide sufficient quantities of fertile materials to power fast reactors almost indefinitely, thus saving 100% of the natural uranium resources.
In general, recycling options offer more opportunities to bring direct and indirect benefits to economic development compared to the open cycle.
Social acceptance is a common question for all the options corresponding to the social acceptance of nuclear energy as a whole. Social acceptance is generally higher when stakeholders are well informed and there is less uncertainty. In this way, the monorecycling option offers additional advantages to generation in the future. Multi-recycling options represent an important potential benefit for future generations by providing a set of technologies that maximize the conservation of natural resources and the reduction of waste. These environmental impacts must be taken into account in the valuation because they represent increasingly important social concerns.
1.1.3. Economic evaluations
The management of spent fuel and related waste requires a long-term, multidimensional global systemic approach that takes into account factors such as:
long-term energy mix plan: installed and future nuclear capacity (including the exit from nuclear power);
national and international policies and regulations;
the available resources, including natural uranium, financial resources and technologies/industrial infrastructure;
social acceptance;
geology;
R&D planning of reactors and site remediation;
valuation/sale of assets after cessation of nuclear production.
The entire nuclear fuel cycle (from the supply of natural uranium, upstream services, fuel supply), and in particular the spent fuel management program (surface storage, transport, reprocessing/recycling of spent fuel in the event that the recycling option is chosen, waste conditioning for placement in deep geological storage), is implemented in stages. All the steps and their interfaces must be considered holistically in order to evaluate the overall technical and economic performances and values. These comparisons are made taking into consideration the specific context of each country and/or each electrical sector.
1.1.3.1. Theoretical LCOE evaluations of cycle options
Numerous theoretical studies have been carried out over many years to carry out a general and idealized comparison of options for the cycle of a nuclear power system at equilibrium with a net present value (NPV) calculation (Piet et al. 2007).
As an example, we can cite the NEA study, published in 2013 (OECD/NEA 2013). The results of the study show that the costs calculated for the open cycle option are lower than those of the other options evaluated, though the differences between the three options in the component of the total fuel cycle are within the limits of uncertainty, taking into account the uncertainties around certain input data.
Within the idealized and simplified analyses of NPV type, for which the discounted costs of deep storage appear to be very low considering the implementation time (∼100 years after the reactor unloading of the spent fuel), the value of the recycling options is often underestimated, making the option of direct fuel storage slightly more economical (Kim et al. 2015).
These evaluations make it possible to understand the major impacts on the downstream costs of the various options and, more precisely, to identify the cost factors. However, such an assessment cannot simply be transposed into a specific national decision-making context for cycle options. To this end, more detailed and adapted analyses, which take into account the decision-making factors in the valuation, must be developed.
1.1.3.2. The alternatives in the implementation of the spent fuel management program
Running contrary to the theoretical evaluations mentioned in section 1.1.3.1, there are a number of decision-making benchmarks in the implementation of the spent fuel management program to be considered. A series of options may be available over time. For example, various spent fuel storage options can be evaluated close to the reactor pool storage period, including examples such as different underwater or dry storage system technologies implemented on reactor site or at a centralized location. These options are evaluated for use as long-term surface storage pending the preparation of waste packages for future storage, or storage pending reprocessing/recycling of spent fuel. The spent fuel management system involves multiple decisions over a long period of time. Many of these decisions include competing objectives or driving criteria, uncertainties and alternative solutions evolving with market conditions and sociopolitical considerations.
The uncertainties and risks to be considered are of different natures. Some are economic, such as the future cost of commercial services or the required investment expenses, and others are technical, such as the management of the extended surface storage period of spent fuels due to the delayed implementation of the installations for packaging spent fuels in waste packages for further storage. The evolution of the market price of natural uranium is also an important factor. Among other things, this will have an effect on the perceived usefulness of fast neutron reactor technology (4th generation) and as such, the timing of its commercial deployment, which is not currently planned until the second half of this century. This factor will be balanced with the benefits on the savings of natural uranium resources and the minimization of long-lasting waste to be managed.
Sociopolitical considerations are significantly important, including the evolution of installed nuclear capabilities, safety and security requirements, the social acceptance of spent fuel management options and radioactive waste management solutions. Last but not least, the financial aspects (capitalization rate, financial rate of return and the financial performance of nuclear reactor operators) will also play an important role in the path that is chosen. The relative importance of these aspects is specific to each context and can change over time, such that the valuation of the different factors differs by country, and the priorities can change over time.
Future developments may also lead to a wide range of alternative solutions using existing partial industrial reprocessing and recycling capacities that may be deployed pending the future development of advanced reactors, such as capacities adapted to reprocess various types of spent fuels in line with fuel design improvements (ATF or others), or the development of advanced fuel concepts making it possible to multi-recycle plutonium in a light water reactor (e.g. Remix or MOX2 fuels) (IAEA 2019).
There are several options, which can be subdivided into different scenarios, that can be implemented during the long management period until an operational deep storage space is ready to accept the spent fuel packaged in waste packages or vitrified canister. The development efforts leading to the provision of improved industrial solutions offer flexibility in the spent fuel management program in order to minimize risks and contain costs, thus improving the overall financial predictability of the complete spent fuel management solution.
Technological developments, changing market conditions and societal trends require a periodic reevaluation of the spent fuel management strategy in order to understand both new opportunities and new challenges.
The developments made in deep geological storage projects have particularly significant financial impacts in the case of the open cycle when the residual operating time of the nuclear reactor is limited.
1.1.3.3. Advanced evaluation methodologies
Using a progressive implementation makes it possible to minimize the management costs of spent fuels and to mitigate programmatic risks, prioritizing flexibility to adapt to future development. It also requires valuing long-term goals in short-term decisions.
The future value of an option also depends on the developments made to keep this option open, corresponding to the value to be lost or gained when this option is no longer available. There is an opportunity cost to keeping an option open or closed. Maintaining options has a cost; the decision to limit or abandon an option or an option should be taken into account during the periodic re-evaluation of the strategy, considering the potential difficulties, issues, and risks and opportunities.
From a methodological point of view, we can list the following potential problems:
an approach recognizing the benefits of limited early disbursements but underestimating future uncertainties or risks;
an approach to waiting that does not include a regular reassessment of the options that have remained open;
a simplified economic approach using static models of idealized options.
The issues related to the evaluation can also be explained by:
avoiding saturation of reactor pools by ensuring a safe and convenient interim storage solution;
the safe and optimal development of deep geological storage;
the reduction of environmental impacts and storage allowances;
ensuring the robustness of the financing selected;
obtaining the support and trust of the public.
Finally, we can then give the value factors to be taken into account:
the preservation of natural resources;
the promotion of a circular economy;
the contribution to the security of the supply;
the reduction of the waste to be put in storage to a minimum;
the optimization of costs for the safe and secure management of spent fuels and waste.
It should also be mentioned that postponing a decision without a regular reassessment can actually lead to the unintentional closing of options. The interest of keeping the option open will depend on the progress of the implementation of the program. Once the final point has been reached, the value of flexibility is likely to be reduced.
The assessment of plausible future scenarios can guide companies or governments and their stakeholders toward appropriate risk mitigation strategies that correspond to the specific context of each nuclear power plant operator, including its cost objectives and exposure to financial risks in dynamic and uncertain market environments (Passerini 2012; Wigeland et al. 2014).
A spent fuel management system that lasts for a very long period of time (beyond 100 years) requires a systemic consideration valuing costs, risks, time, technological developments and social concerns.
In this context, NPV or LCOE type evaluations are no longer sufficient (Havlíček 2008; NNWI 2020) and innovative evaluation methodologies integrating costs, risks, time and options are essential to develop an optimal spent fuel management program for the purpose of:
adapting to the uncertain socio-political-economic environment of the various stakeholders;
minimizing the costs and risks of deployment thanks to a progressive implementation, valuing flexibility to adapt to development and future alternatives;
evaluating long-term goals as part of short-term decisions;
considering the sharing of infrastructures that would particularly benefit countries with small nuclear programs.
The valuation methods of real options typically make it possible to accommodate these needs in a dynamic analysis specific to the context studied (Jain 2012; Läuferts 2012).
1.1.4. Deep storage as a preferred solution
There is no optimal solution that would lead all countries to a common cycle option or to a single spent fuel management strategy. So far, countries have made their decisions based on their history of nuclear energy development and the values they place on the different characteristics of fuel cycle options, as well as their point of view on the long-term use of nuclear energy. Energy policy can also evolve over time, which leads to the transition from a preferred solution to another option. A spent fuel management system extends over a very long period of time (beyond 100 years) and requires a holistic evaluation via the use of innovative evaluation methodologies, beyond simple NPV analyses, which include costs, risks, time and alternatives.
Today, the development of a deep geological storage facility for final waste disposal is considered the best available solution, regardless of the cycle option that is chosen. Access to suitable geological conditions and characteristics and the development time of these installations currently constitute some of the most important issues for all stakeholders at the global level, inducing significant uncertainties in the management programs that must be integrated. Technological developments, including those involving SMRs (small modular reactors) or advanced modular reactors and/or advanced fuels, changes in regulations, the evolution of market conditions and societal values require a periodic reassessment of the spent fuel management strategy to understand new opportunities and new challenges. The implementation of management programs is carried out in stages with a holistic assessment of alternatives to multiple decision points via the use of adapted methods taking into account the various dimensions, costs, risks, time and options.
1.2. Costs and methods of financing radioactive waste management
1.2.1. Introduction
The management of radioactive waste takes place over the very long-term. It essentially consists of isolating these wastes from the biosphere, containing them and the delay of the dispersion of their radioactive components so as to allow the reduction of their harmfulness by radioactive decay. The duration of radioactive decay is a physical property of matter; it is measured in half-lives, the time necessary for the radioactivity to have decreased by half. A half-life is a characteristic of the physical element; it can be relatively short (8 days for I131, 30 years for Cs137) or long to very long (24,110 years for Pu239, 301,000 years for Cl36).
The methods to be implemented for the management of radioactive waste must therefore allow for the waste to be isolated over very long periods of time. These periods go far beyond what can be controlled on the scale of societies and civilizations. It is therefore necessary to devise a management method that does not call for human intervention over time.
Storage in a deep and stable geological layer has been the subject of a consensus for many decades as to its ability to respond to the challenge posed. After its closing, it can operate autonomously without human intervention for the required periods. Naturally, it is up to the safety studies to confirm this design choice.
Deep geological layer storage in practice forms part of the logic of sustainable development and intergenerational equity as defined at the Earth Summit in Rio in 1992; these two concepts recognize that “development that meets the needs of current generations must be done without compromising the ability of future generations to meet their own”, on the one hand, and that it is necessary to “avoid postponing negative consequences (environmental, economic and social) on future generations” of our development model, on the other hand.
In this case, scientific reasoning meshes with the moral duty that current generations have to create a solution for the management of radioactive waste respectful of future generations as soon as possible, and in any case without undue delay.
The option of long-term surface storage clearly does not meet the requirements set out above; even if it can be considered safe on a century-wide scale, there is no guarantee that future societies will have the intellectual and material means to perpetuate it almost indefinitely. Indeed, a surface storage facility differs from a storage facility in that, first of all, the materials or waste is stored there with the intention of recovering them, and second, by contrast, there is no intention of recovering them: the storage is the final stage in the process. The monitoring and maintenance of the stockpile and the materials or waste stored there must therefore be ensured on an ongoing basis and the guaranteed feasibility of transport out of the stockpile.
The integrity of the structures and the operability of the surface storage facilities are inevitably limited in time, though it is projected they will last beyond the end of the century. The surface storage must therefore be renewed periodically and the materials or waste contained therein transferred to a new facility; consequently, surface storage cannot be considered either as permanent or as a definitive solution; a storage system must ultimately be put in place. Ensuring the cost coverage of a procedure that is so uncertain in its scale and carried out over such a long period appears to be almost completely infeasible with the economic tools available: any future updates would annihilate distant costs and inflation would destroy the value of the provisions. Multisecular surface storage thus implies a transfer of resources, both technical and financial, to future generations. This does not respond to the notion of ethical responsibility, that is to say, the obligation we have to be accountable for our actions and to bear their consequences, and therefore will not be discussed here.
The assumption of responsibility by the current generations implies that they assume the costs of the management to be put in place. These costs must therefore be estimated as best as possible and the means to ensure that their coverage is put in place. In this context, section 1.2 is divided into two main sections. The first, section 1.2.2, deals with the analysis of the costs related to the long-term management of radioactive waste. Section 1.2.3 addresses the financing mechanisms that seek to ensure the financial coverage of the long-term management of these wastes.
1.2.2. Analysis of the costs related to the long-term management of radioactive waste
1.2.2.1. Context
As mentioned in the introduction, in the particular case of the management of long-lived intermediate activity waste (LL-ILW) and HLW, there is a broad international consensus on geological storage in galleries in a host geological formation as an adequate solution for the management of these long-term wastes. This consensus has also manifested itself in the political choice for its implementation in several countries, including Finland, France, Sweden and Switzerland. This solution is also recommended by ONDRAF1 in Belgium.
Box 1.1.Advantages and disadvantages of deep drilling
In the case of geological storage, most of the developments (research, development and demonstration) concern geological storage in galleries. However, it should also be noted that in parallel with this solution of geological storage in galleries, research has been carried out at an international level on geological storage in deep boreholes for high activity and/or long-life packaged waste (these are essentially conceptual studies). Storage in vertical deep boreholes2 conceptually consists of the “unloading” of packages of radioactive waste packaged in narrow boreholes with a depth of more than 1,000 m (see Figure 1.6). Most studies call for the storage of waste in boreholes that can reach a depth of 5–6 km. The storage zone, located in the lower part of the boreholes, can reach 2 km and have a diameter of between about 40 and 90 cm. The annular space between the lining of the borehole and the surrounding environment and that between the waste packages and the lining of the borehole can be filled with materials chosen so that the storage system achieves the best possible performance. Horizontal “plugs” are placed at regular intervals in the storage zone in order to reduce both the vertical pressure on the waste packages and the risk of radionuclides and chemical contaminants rising up along the walls of the borehole. The drilling segment located above the storage area must be adequately closed. After the borehole has been completely closed, the system, in theory, will safely and passively confine and isolate the radioactive waste for as long as is necessary.
The main advantages of deep drilling are as follows:
the lack or near lack of groundwater movement at the depths at which the waste is stored, and the low probability of contact with the groundwater system closer to the surface, which itself is connected to the biosphere;
the significant thickness of all the geological layers that isolate the waste from the biosphere;
the impossibility, or at a minimum the extreme difficulty, of recovering the waste after the complete closure of the boreholes (for the types of waste that it would be desirable to never be able to recover, such as for reasons of non-proliferation).
The main disadvantages of deep drilling are the following:
according to some opinions, the storage system is essentially a mono-barrier system, where the only real barriers are geological (the host formation and some of the upper geological layers);
the relatively limited diameter of the packages that can be put in storage;
the impossibility, or at least the extreme difficulty, of recovering the waste after the complete closure of the boreholes.
Although this area continues to evolve, the concepts of geological storage in underground boreholes remain significantly less mature than the concepts of geological storage in galleries, both from the point of view of the technologies to be implemented and that of the scientific capacity to demonstrate that such storage systems are able to protect humans and the environment from the risks posed by waste for as long as necessary.
According to the polluter-pays principle, producers of radioactive waste must generate sufficient income starting from the present time to cover future needs in terms of financing geological storage facilities. The period of time between the generation of income by waste producers and the first expenses generated by the development of geological storage can range from a few decades to more than a century. This significant duration requires establishing a cost estimate that is reliable in order not to transmit the financial burden of the long-term management of radioactive waste to subsequent generations. This results in the need to develop a cost calculation methodology that makes it possible to obtain a transparent, traceable and robust cost calculation and that can take into account all the uncertainties related to this calculation and the geological storage program. These uncertainties stem from various causes, in particular technological issues or those related to the degree of maturity of the program3 for geological storage.
Figure 1.6.Principle of geological storage in deep drilling (source: Freeze et al. 2019).
In this context, many countries have developed their own methodology by integrating input from past experiences (feedback) from projects related to the nuclear industry (construction or decommissioning of new power plants) and megaprojects4. These methodologies, although each presenting different specificities, share a similar approach and are built according to recurring patterns.
The first section of this chapter presents the main principles that can be found in the cost analysis methodologies applied in different countries (Belgium, Finland, France and Switzerland in particular) as well as in numerous international guidelines (such as NASA 2015; OECD/NEA 2017; GAO 2020; IAEA 2020).
The following sections present a synthesis of the main principles that are found in the cost analysis methodologies referenced above. However, it is important to note that there are many methodologies that have been developed in different countries and for different types of projects and which, even if they are based on similar principles, may differ in how they are applied specifically. The following sections also present certain specific considerations implemented in the methodologies developed by ANDRA5 (France) and the ONDRAF (Belgium).
1.2.2.2. Generic methodology for analyzing costs
The purpose of this cost analysis methodology is to determine the costs of implementing geological storage, without taking into account inflation and price adjustments. Inflation and the adjustment rate are discussed in the next section on financing mechanisms. The costs, excluding inflation and adjustments, are the non-adjusted gross costs (also referred to in some countries as overnight costs, in other words, as if the project were carried out instantly).
The analysis of the costs for geological storage, and in general for any industrial project or program, must be carried out on the basis of a transparent, trackable and robust process:
Transparency: each stakeholder (waste producers, the organization in charge of waste management, decision-makers and the public) can share the same understanding of the project and its cost analysis, which allows for increases in the mutual trust of the various actors.
Trackability: each hypothesis is identified, and each data used are justified and their origin is clearly documented. This traceability is a prerequisite to guarantee the quality of the estimate (avoiding double counting and omissions among other things) and its credibility.
Robust: the cost estimate obtained by applying the cost analysis methodology can cover the impact of minor or even more substantial modifications to the program.
The cost analysis methodology is an iterative process, as illustrated in Figure 1.7. This process can be divided into 12 steps, which are divided into four phases.
Figure 1.7.Iterative and sequential process for cost analysis.
1.2.2.3. Phase I – definition of the program
1.2.2.3.1. Definition of the objective of the cost analysis (step 1)
Before starting the cost analysis, it is essential to define its objective. This may be a comparison of different geological storage options (especially options related to the selection of one or more storage sites and/or in different host rocks), a budget estimate for the financing of the program, or a cost analysis that forms part of the monitoring of the realization and execution of the program.
The degree of precision required will then be established on the basis of the objective sought, but also on the degree of the technical maturity of the project. This degree of maturity is generally linked to the stage of progress of the program: conceptual, feasibility, the simplified preliminary project (SPP), the detailed preliminary project (DPP), procurement, or execution.
1.2.2.3.2. Identification of the assumptions and the scope of the calculation (step 2)
The scope of the calculation allows us to distinguish between the costs included in the calculation and which must be financed, along with the costs outside the scope of such calculation and which must not be covered by financing.
The scope of the cost analysis of a geological storage facility covers not only the investment costs as well as all the other costs that are necessary from the time of the authorization of the construction and operation of the geological storage (T0)6 until its closure (TC) (the costs related to the post-closure phase [institutional control] are also included) (see Figure 1.8)7. These costs include the cost of engineering studies, construction costs, operational costs (including those related to maintenance and renovation)8 and the costs of closing the storage facility (including operations to dismantle surface facilities). In other words, the cost analysis of a geological storage requires a complete analysis of the costs of the lifecycle of the program (lifecycle cost analysis).
The scope of the calculation, supplemented by all the assumptions necessary to calculate the costs of a geological storage project, forms the reference scenario. The reference scenario is critically important in the calculation.
Figure 1.8.The temporal phasing of a geological storage and the schematic evolution of activities during the program: construction, disposal of waste, partial closure of the storage galleries and final closure.
Figure 1.9.Chronic delivery of radioactive waste (intermediate-level and long-lived waste [LL-ILW] and high-level waste [HLW, Cigeo geological storage program]; source: ANDRA 2014).
The reference scenario brings together:
the legal framework;
the regulatory requirements, established by the nuclear safety authority and other competent authorities (e.g. mining regulations);
the assumptions about the location of the storage (for the least advanced programs);
the hypotheses related to the construction, the operability and the closure operations of the geological storage, as well as the determination of the phases of these different tasks;
the inventory of the primary packages of radioactive waste, as well as their delivery rate on the site of the storage facility. An example of a forecast delivery schedule for radioactive waste for the French geological storage program under the responsibility of ANDRA (Cigéo project) is provided in
Figure 1.9
.
1.2.2.3.3. Description of the geological storage technical program (step 3)
This technical description describes the geological storage facility, as well as the main phases from the start of construction to the closure of the storage facilities (geological storage planning). The technical description consists of calculation notes, studies, and plans carried out by the engineering offices. The degree of maturity of the technical file depends on the progress of the development of the technical program.
