The Contribution of Fusion
to Sustainable Development

Contents

• Introduction
• The Basic Case
• Energy demand
• Alternative energy sources
• Environmental impacts of fossil fuels
• Fusion and the environment
• Economics
• Strategy and timescales
• The UK Fusion programme
• Concluding remarks
• Reference

In the long term, fusion offers an additional, secure, virtually resource unlimited, source of electricity supply, and has been found by an independent review body [1] to possess "inherent environmental and safety advantages over all current alternatives for base load electricity generation". The potential contribution of fusion to long-term sustainable world development is thus very great.

However, it is not yet certain that fusion's potential can be realised in an economically acceptable form: determining whether or not this can be done is the purpose of the world- wide fusion R&D programme. That programme, as presently constituted, aims to bring fusion technology to a commercially usable state for electricity generation by about the year 2040. (The pace of the programme could be changed if desired.) Thus, fusion would be entering the market in a world in which the demand for energy is expected to be much greater than it is today, in which reliance on fossil fuels is expected to be constrained by environmental imperatives, and in which there is expected to be substantial reliance on nuclear fission. The case for pursuing fusion R&D is based on the major environmental and economic benefits which the timely availability of fusion power is likely to yield.

• In the course of the next half-century the world is going to need a lot more energy at economically and environmentally acceptable cost, if the reasonable aspirations of an expanding population are to be met.
• Although energy efficiency improvements will occur, substantial overall growth in demand is unavoidable.
• The supply options comprise fossil fuels, fission, fusion, renewables (solar, wind, tidal, waves, ocean thermal gradients and hydro), biomass and geothermal heat.
• In the United Kingdom, there is only limited scope for significant contributions from renewables, biomass and geothermal heat.
• Newly recognised environmental imperatives - control of the greenhouse effect and of the effects of acidic pollution - mean that reliance on fossil fuels will have to be severely constrained.
• Nuclear fission has the ability to make a long-lasting major contribution but suffers from problems of public and political acceptability.
• Fusion offers an additional, secure, virtually resource-unlimited, source of supply, with important environmental advantages:
  • The consequences of even the most unlikely incidents would be very limited in scope.
  • The wastes arising from the operation of a fusion plant would not require isolation from the environment for a prolonged timespan.
  • Safety would be readily demonstrable to the non-scientist.
  • No contribution to greenhouse gases or acidic emissions.
• Because of the environmental advantages summarised above, there should be no constraints on grounds of public acceptance to the widespread, intensive and indefinite deployment of fusion power.
• Present indications are that the cost of fusion-generated electricity will be similar to the cost of fossil-fuel-generated and fission-generated electricity.
• Thus involvement in the world-wide programme to bring fusion technology to a commercially usable state is a wise contribution to sustainable development.

The two main factors which will lead to greatly increased world-wide demand for energy during the next half-century are population growth, and per capita economic growth, in the less-developed countries. The population of the less-developed countries is predicted to increase from the current value of four billion to over eight billion by 2050, at which time it will comprise almost ninety percent of the world population [1]. Predictions of per capita economic growth for the less-developed countries cannot be made with any confidence, but the strength of the trend is incontrovertible: the average person in the less-developed countries currently consumes only one sixth of the energy consumed by the average person in Western Europe or Japan. Doubling of per capita energy consumption in the less- developed countries, over the next fifty years, would correspond to only a very modest degree of economic development: yet, combined with the predicted population increase, it would lead to a twofold to threefold increase in world energy consumption. The actual increase in demand may be expected to be greater: for example, there will be increased demand from economic growth in the developed countries.

Improvements will undoubtedly occur in the efficiency with which energy is utilised, but, in the face of the expected increases in demand discussed above, these could only have relatively minor impact.

Extensive use is already made of hydropower sources where these are available but the potential for further expansion is limited, particularly in the developed countries.

Tidal power, geothermal sources and ocean thermal gradients have limited and highly local potential. Wave power, solar energy and wind energy are more widely distributed, but only land based aerogenerators have approached economic viability except in very favourable circumstances.

If the costs of solar power can be brought down it could have potential in sunny regions but, like biomass culture, it requires large tracts of land.

The variability and unpredictability of supplies from renewable sources, in the absence of inexpensive large scale energy storage technologies, will limit their ability to satisfy global energy requirements, so that predictable, non-varying, sources will continue to be needed for the bulk of supplies: this means reliance on fusion, fossil fuels, and fission with fast reactors.

Serious adverse environmental impacts arise from the emission of carbon dioxide and the oxides of sulphur and nitrogen, when fossil fuels are burned [2]. The contribution to the "greenhouse effect", stemming from the emission of carbon dioxide which inevitably occurs when fossil fuels burn, may lead to global increases in temperature and sea-level, with resulting shifts in food-producing areas and patterns of disease, and species extinctions [2]. These changes, and the migration of people they could cause, could affect peace and international security [2]. Acidic pollution, arising from the emission of the oxides of sulphur and nitrogen, is implicated in the increasing incidence of asthma and other respiratory diseases, the acidification of lakes, and damage to trees and buildings.

Increasing public pressure to limit or reduce these emissions will severely constrain the reliance that could be placed on fossil fuels as a source of increased energy supply. Unless this lost fossil fuel output is replaced on a large scale by accepted alternatives, the cost, in terms of economic development foregone, will be very high.

Fusion has been recognised by an independent review [1] as "possessing inherent environmental and safety advantages over all current alternatives for base load electricity generation". The origin and nature of these advantages are discussed briefly below.

The fusion fuel cycle does not involve any input of radioactive material and does not generate radioactive waste directly, but radioactivity is nevertheless present in the form of the intermediate fuel, tritium, and as parasitic radioactivity generated in structural materials by the absorption of neutrons. There is the freedom, by suitable choices of design and materials, to reduce the radioactive inventory to achieve low hazard potential. Studies in this area have been promising [4, 5] and the independent review prepared for the CEC by the Fusion Programme Evaluation Board [1] was able to propose the following stringent targets as reasonable aims for the Fusion Programme:

• "The worst possible fusion accident will constitute no major hazard to populations outside the plant perimeter that might result in evacuation."
• "Radioactive wastes from the operation of a fusion plant should not require isolation from the environment for a geological timespan and therefore should not constitute a burden for future generations."

The independent Evaluation Board concluded that the above objectives "are viable targets with careful design and materials development, but their attainment should not be taken for granted".

Because the safety and environmental friendliness of fusion are grounded largely in passive and inherent features of the design, rather than on highly reliable safety systems, they should be more readily and transparently demonstrable to the non-scientific community.

A major three-year project was run within the European Fusion Programme, in 1992-95, to study further how fusion's inherent safety and environmental advantages can be realised in feasible power station designs.

Fusion also possesses advantages in the area of non-proliferation. Under IAEA statutes, none of the materials present in a fusion power station are categorised as being of safeguards significance or require Non-Proliferation Treaty controls. However, because fusion neutrons could be used to generate fissile material, fusion power stations will have to be subject to international safeguards. Such safeguards would be much cheaper and easier to enforce than is the case with fission, because one would be looking for fissile or fertile material in an environment where none at all should be present, in contrast to looking for small discrepancies in large inventories. The procedures could be relatively simple and conducted at intervals with no diminution of their credibility [3, 4, 5].

Because of the environmental and safety advantages summarised above, the widespread, intensive, and indefinite deployment of fusion power plants is unlikely to be significantly constrained by problems of public or political acceptability.

It is convenient to divide costs into two categories: conventional costs and those associated with environmental and safety concerns. Neither category of cost can be estimated with any precision for fossil fuels, fission or fusion fifty years hence, but the present understanding is outlined below.

The fuels for fusion, deuterium and lithium, have a widespread and abundant distribution and extraction costs are low [4, 5]. Thus the conventional costs of electricity generated by fusion will be dominated by capital costs. Because of the uncertainties of extrapolating from present-day experiments to power plant conditions, a range of cost-of-electricity estimates can be found [4, 5]. These range from parity between fission, fusion and fossil fuels, to a factor two to fusion's disadvantage.

Fusion has the advantage when one turns to the costs associated with safety and environmental concerns. Such costs comprise the costs of any harm done and the costs of complying with measures designed to prevent harm being done. Fusion's inherent advantages in this area (described in Section 6), and the transparent demonstrability of such advantages, imply that fusion power stations would have no significant associated costs of either type. Fossil fuels are at the opposite extreme. The costs of global climatic change and acidic pollution (see Section 5) are likely to be very high. So also will be the costs of complying with measures designed to limit the emissions responsible for the harm. A variety of such measures may be envisaged [2], but it is common ground that, for fossil fuels, "In the long term, action will inevitably have to include increases, achieved by taxation or other means, in the relative prices of energy and fuel" [2]. For fission, given the appropriate regulatory environment and safety culture, the expected costs of harm done are known to be small. The real problem is the costs associated with complying with measures needed to secure public acceptance. Public concern, and the associated compliance costs, may increase if it becomes necessary for fission to replace fossil fuels on a large scale all over the world.

In order to obtain the benefits of the availability of fusion, at the time when those benefits are likely to be urgently required, the option should be established by about 2040. This requires the achievement of the following objectives: demonstration of "ignition" (a self- sustaining fusion plasma); demonstration of solutions to material physics problems in ignition conditions; demonstration of the ultra-safe generation of large amounts of electricity; and demonstration of economic acceptability. Present day experiments (especially JET) are investigating the conditions close to ignition and provide clear and compelling evidence that there are no obstacles to the achievement of ignition in future devices.

The current plans of the international fusion programme envisage achievement of the other objectives via a sequence of overlapping steps. The viability of this programme has been independently examined by the Evaluation Board appointed by the CEC. The Board accepted in broad terms the strategy of the programme and concluded [1] that, on the basis of the progress achieved so far, the ultimate objective appears to be realistic, and that a prototype fusion power station, that can be considered "first of a series", can be expected to operate around 2040. It must be emphasised, however, that the above timetable is not a necessary feature of the technologies. It could be accelerated if required.

Because the costs of either accepting or averting global climatic change will be high, it is important to choose the optimal combination of measures. For such purposes, a major theme of Government policy is that we must rely on "facts not fantasy: ... environmental policies must be based on the best scientific and economic information available" [4]. Fusion is expected to play a major role, in the long-term, in reconciling economic growth with climatic stability.

As expounded in the White Paper "This Common Inheritance" [4], Government policy, concerning the means by which continuing economic development may be reconciled with the prevention of environmental harm emphasises that "action in Britain alone is not enough", and that "Tackling many environmental problems needs a concerted international approach". "Acting together, the (European) Community countries can take the lead in finding solutions to pressing global problems".

The UK Fusion Programme has been, for some years, organised in conformity with those principles. The UK programme is a closely integrated element of the Fusion Programme of the European Union. This consists of a central programme, mainly comprising the JET experiment, sited at Culham in the UK, and a set of national programmes. To the national programmes are delegated specific investigations and tasks which supply needed information to, or otherwise support, the central programme. The existence of the national programmes is also valuable in providing a source of expert advice to national governments when the merits of proposed new international programmes are under debate. In turn, the European Fusion Programme is a partner, with the USA, Russia and Japan, in the world-wide fusion programme. (Other nations, including several less-developed countries, also contribute.) Arrangements for different partners to focus on key elements in the programme, thereby avoiding duplication, are planned to continue in an increasingly structured form.

Good co-ordination of both the European and world-wide programmes has been obtained with low cost in administrative effort. Co-ordination has largely been effected by co- operative action, rendered possible by the high degree of esprit de corps characterising the world-wide fusion research community. By these means, for a very modest outlay, Britain makes a very effective contribution to the solution of major global problems.

Because fusion "possesses inherent environmental and safety advantages over all current alternatives for base load electricity generation" [1], its development is a very important ingredient in any strategy designed to allow economic growth to continue world-wide in the longer term, without generating major global environmental deterioration. Thus the case for investing a small part of our current output in the development of fusion is an aspect of the more general case, promoted in the White Paper "This Common Inheritance", for "sustainable development, which aims pass on man-made and natural resources so that future generations are no worse off than this one" [4]. Fusion technology brought to fruition would be an asset of the utmost value to give to our descendants.

1. U. Colombo, et al., "Report of the Fusion Programme Evaluation Board". CEC, July 1990.

2. J.P. Holdren, et al., "Report of the Senior Committee on Environmental, Safety and Economic Aspects of Magnetic Fusion Energy". UCRL-53766 (1989).

3. EEF Study Group, "Environmental, Safety Related, and Economic Potential of Fusion Power: Main Report", Brussels, Dec. 1989.

4. "This Common Inheritance: A Summary of the White Paper on the Environment". U.K. Dept. of the Environment, HMSO, 1990.

5. K.C. Zachariah and M.T. Vu, "World Population Projections, 1987-88 Edition". Published for the World Bank by Johns Hopkins Univ. Press, 1988.