This article was originally published in the December ’89/January ’90 issue of the SCRAM Safe Energy Journal. It remains relevant to the debate on nuclear power and climate change.
Global warming and its possible consequences is one of today’s most pressing environmental issues. It has been eagerly seized upon by those who seek to restore the tarnished image of the nuclear industry. Dr NIGEL MORTIMER, an energy consultant and Senior Lecturer in Minerals and Resource Economics at Sheffield Polytechnic, examines the nuclear panacea and finds it notably lacking.
Speaking on BBC television a year ago the then Secretary of State for the Environment, Nicholas Ridley, stated that, “There is absolutely no doubt that if you want to arrest the Greenhouse Effect you should concentrate on a massive increase in nuclear generating capacity. Nuclear power stations give out no sulphur and carbon dioxide, so they are the cleanest form of power generation”. Despite subsequent qualifications to these views, it is obvious that Mr Ridley was acting as the stalking horse for a Prime Minister and a Government that clearly favour nuclear power. Those responsible for the public relations campaigns of the nuclear and related industries have taken a more subtle, yet no less emotive approach.
Faced with a widening gulf between image and reality over nuclear economics, safety, radiation hazards, nuclear weapons proliferation, decommissioning and waste disposal; the greenhouse effect and global warming has provided a welcome lifeline for beleaguered public relations staff. In expensive double-spread advertisements, British Nuclear Fuels pic proclaim, “The Greenhouse Effect. We have the power to prevent it” and nuclear power is portrayed as “a source of clean energy for the future”. Mindful of rules governing factual content in advertising and wary of an audience that has become better informed through bitter experience: National Power, one of the intended successors to the Central Electricity Generating Board, explains in its recent publicity that, “Although not implicated in either the greenhouse effect or acid rain, nuclear power generation does, of course, present its own set of environmental concerns”.
Thus, the basic concept of nuclear power as our only saviour from the threat of global warming is gradually being introduced to a public disenchanted with the nuclear industry yet eager for simple solutions to world problems.
This strategy of persuasion is not new. It is familiar to those who have taken part in the debate over energy policy in the UK, in recent decades. Nuclear power has been heralded as the only solution to fuel shortages during the 1960s and to rising fuel prices and fears of fossil fuel resource depletion in the 1970s. As was pointed out by the more rational and independent analysts of the time, such problems could not be solved by expanding nuclear power. Instead, other factors, such as cheap oil imports during the 1960s, and the development of cheap natural gas supplies and oil production from the North Sea, coupled with improvements in energy efficiency during the 1970s, proved to be considerably more influential than nuclear power.
However, those who realised this and dissented against the popular image of the nuclear panacea were dismissed and labelled as anti-nuclear heretics. Undoubtedly, the same fate awaits those who are questioning the latest excuse for committing yet more scarce resources to the development of nuclear power. Some, such as Dr Bill Keepin and Dr Greg Kats, have already demonstrated that the rapid expansion of nuclear power on a global scale is impractical and that more effective options are available to control carbon dioxide emissions (Ref. 1).
Despite such efforts, two fundamental questions which are central to the whole debate about nuclear power and global warming remained unanswered. These were, “Does nuclear power contribute to carbon dioxide emissions?” and “Can nuclear power provide a realistic long-term solution to global warming?”. In order to answer these two questions, Friends of the Earth commissioned a study begun in January ’89 which resulted in evidence being presented to the Hinkley Point “C” Pressurised Water Reactor (PWR) public inquiry in July (Ref. 2).
In order to answer the first question, it is important to realise that all activities currently result in the emission of the greenhouse gas carbon dioxide due to the combustion of fossil fuels, either directly in the activity itself or indirectly during the provision of goods and services consumed by the activity. Hence, although nuclear power does not emit carbon dioxide directly, associated emissions occur due to fossil fuel combustion during the construction of the power sta tion, the manufacture of components and the operation of the nuclear fuel cycle.
Using appropriately adjusted results obtained from studies involving a technique known as energy analysis, preliminary estimates of the effective release of carbon dioxide were derived for a selection of energy technologies and energy efficiency measures. Results, showing the average annual amount of carbon dioxide emitted for a given amount of electricity, either generated or saved, equivalent to the lifetime output of a 1,000 MW PWR (171TWh), are summarised in Figure 1. The relative contributions to current carbon dioxide emissions from a typical PWR and associated fuel cycle over its entire 35 year life are illustrated in Fig. 2.
The results clearly indicate that the selected renewable energy technologies and energy efficiency measures release considerably less carbon dioxide than currently operating PWR nuclear power stations. However, nuclear power does, at the moment, offer dramatic reductions in carbon dioxide emissions over electricity generation from conventional coal-fired power stations. Even greater savings might seem possible when it is realised that the bulk of carbon dioxide emissions associated with nuclear power at present arise from fossil fuel-fired power stations that are providing the majority of electricity used in uranium fuel enrichment.
Such enrichment is mainly achieved using the gas diffusion method which will eventually be replaced by much more efficient techniques which include the gas centrifuge method. If this occurs and all the electricity used for construction, manufacturing and fuel cycle operation, including enrichment, is provided solely by nuclear power stations then the carbon dioxide emissions from nuclear power might be reduced from the present average figure of about 230,000 tonnes per year to approximately 21,000 tonnes per year. This estimate can be taken as representative of the ultimate nuclear power system, based on existing technology, which provides electricity for all needs.
Given time to achieve all the necessary requirements, such a system would seem to offer an attractive solution to carbon dioxide emissions and subsequent global warming. However, at this point, it is essential to consider the second fundamental question which asks whether nuclear power is a long-term solution. A key concern in the world supplied by electricity entirely generated by nuclear power would be the adequacy of uranium resources. Although there is currently a glut of uranium on world markets due to slack demand in the nuclear industry, high quality uranium resources in known deposits are relatively limited. The quality of uranium resources dm largely be characterised by the percentage uranium content in the ore, referred to as the ore grade. As the ore grade falls, the amount of energy used in ore mining and processing rises, and, hence, the’ amount of carbon dioxide released by burning fossil fuels in non-electrical applications should be expected to increase. The likely variation of carbon dioxide emissions with uranium ore grade is illustrated in Figure 3. The bands shown in this diagram indicate the range of uncertainty and differences in assumptions used in the calculations. However, it can be seen that the relationship between carbon dioxide emissions and uranium ore grade is quite strong and, it is particularly apparent that, if the ore grade falls to anything less than 0.01% uranium oxide then the nuclear power system could release as much carbon dioxide as fossil fuel-fired power stations. This ore grade can be regarded as a limit to the use of nuclear power as a solution to global warming.
The imposition of such a limit restricts known resources for nuclear power in the western world to just under 6,000,000 tonnes of recoverable uranium. Such resources could sustain the current modest nuclear generating capacity, which accounts for only 10% of total installed output worldwide, for about 150 years. However, it is implicit within the case for nuclear power, as well as in the above calculations, that nuclear generating capacity would have to grow rapidly and eventually provide all our electricity requirements in order to make any noticeable contribution to carbon dioxide abatement. Limited high quality uranium resources undermine the ability of nuclear power to achieve this, since a resource of 6,000,000 tonnes of uranium would only be able to support a world generating capacity solely based on nuclear power for no more than approximately 23 years. Hence, nuclear power, incorporating existing technology, does not provide a sustainable solution to carbon dioxide emissions and global warming.
But what of fast breeder reactor technology which is considerably more efficient in its use of uranium? This, as the United Kingdom Atomic Energy Authority has already noted (Ref. 3), is vital to any case for nuclear power. However, such a case must be set in context of what is practical in the foreseeable future and the likely timescale of global warming. Present consensus suggests that realistic solutions to carbon dioxide emissions must be implemented within the next 30 to SO years to reduce the impact of global warming.
The possibility of introducing a massive worldwide programme of fast breeder reactors within such a timescale would depend on many technical factors. However, leaving these to one side, the essential considerations are the availability of plutonium and the system doubling time, which is the time taken to provide sufficient plutonium, in the form of usable fuel, for a new fast breeder reactor from the blanket of an existing fast breeder reactor. In this context, nuclear power based on fast breeder technology could only be regarded as a realistic and sustainable solution to global warming if short system doubling times, of the order of 13 years, could be achieved now. Since system doubling times currently exceed 20 years, such a target is clearly well beyond present capabilities.
Any serious examination of nuclear power will conclude that this technology has only a very limited role to play in countering global warming. Other options, including fuel switching and the use of renewable sources of energy, are currently available to provide realistic means of reducing carbon dioxide emissions. The most important options, however, consist of energy efficiency measures which can be introduced quickly and can achieve sustainable savings from a huge diversity of applications in a cost-effective manner. In the fight against global warming, the priorities for action are clear (Ref. 4). Unfortunately, we still run the risk of having attention and scarce national resources diverted – by the illusions on offer from nuclear power – away from the practical strategies that could be adopted and implemented now.
1. “Greenhouse Warning. Comparative Analysis of Nuclear and Efficient Abatement Strategies” by B. Keepin &: G. Kats, Energy Policy, December 1988, Vol. 15, No. 6, pp.S38-S61.
2. “Aspects of the Greenhouse Effect” by N. D. Mortimer, Proof of Evidence FoE 9, available from Friends of the Earth Ltd., 26-28 Underwood Street, London, N1 7JQ.
3. “Nuclear Power and the Greenhouse Effect” Atom, April 1988, No. 390, P .33.
4. “The Greenhouse Effect: A Practical Guide to the World’s Changing Climate” by S. Boyle and J. Ardill, New English Library, 1989.