Total world energy use in 2006 totalled 472 quadrillion British thermal units (Btu). Of this, 55% were derived from gas and liquid hydrocarbon. To avoid economic stagnation or collapse, supply must rise by 44% to 552 quadrillion Btus in 2015, mostly from hydrocarbon resources.[3] Serious concerns exist about the ability of remaining hydrocarbon resources to meet this demand. Nuclear energy technology offers high energy density per unit of resource. Replacing diminishing hydrocarbon energy with nuclear energy is therefore an attractive proposal. However, a number of very significant challenges must be overcome before development of capacity at a scale necessary to address declining hydrocarbon resources can be undertaken. The purpose of this essay is to review these challenges to inform the question: “Is nuclear energy a Good Idea?”.
The challenges to overcome
To be a realistic substitute for existing and competing energy sources, nuclear energy must overcome several challenges which, in this essay, are considered under the following headings: * Necessary Given the magnitude and proximity of the energy gap, the dis- astrous impact on living standards of even small energy shortfalls and the significantly lower energy densities of any alternate technologies, can nuclear technology be rejected on any basis? * Compatible Is it compatible with existing patterns of supply and consump- tion in energy’s various applications in society? * Operable Can it be operated safely at scale, particularly under the condi- tions which might emerge as the energy gap widens? * Sustainable Are sufficient supplies of nuclear fuel available to ensure ade- quate availability of energy?
Is nuclear energy necessary?
The proximity and magnitude of the hydrocarbon resource gap, the lack of significant alternative energy sources and the disastrous impact of energy shortfalls on living standards leave few choices. 55% of total energy consumption is derived from hydrocarbon. Energy uncer- tainty is therefore dominated by hydrocarbon uncertainty. Any gap between supply and demand must be met by some combination of demand reduction, increased renewable sources or increased nuclear capacity. Tolerance of nuclear risks is proportional to the intolerance of energy shortfalls and the inadequacy of any alternatives to prevent them.
A large hydrocarbon gap is imminent
64 of the world’s 100 significant oil producing countries are past their resource-limited peak of conventional oil production.
Comprehensive projections of hydrocarbon supply have been made by energy consultancy firms. Such studies (e.g.[8]) estimate the magnitude and timing of an energy gap by considering most likely growth of energy demand, conventional and unconventional hydrocarbon supply, and demand reductions from efficiencies likely to arise from price increases.
Such models are remarkably insensitive to new information such as the possibility of very large future discoveries, due to the compounding effect of commensurately large present day decline rates. They therefore both support the argument for non-hydrocarbon fuel sources and quantify the required magnitude of those sources.
A typical forecast of future oil supply shortfalls derived from such heuristic models can be seen here. It projects a hydrocarbon supply/demand deficit commencing in 2016 and reaching the approximate current output of Saudi Arabia and Kuwait by 2020.
There are no sufficiently material alternatives
Non-conventional hydrocarbon energy resources and renewable resources–including nuclear–face serious technical, environmental and energy return challenges. Studies (e.g.[2]) show a marked decline in energy return on invest- ment on principle fuels, and wide contrast between hydrocarbon fuel returns and all other fuel types. A selection are shown in Table 1.1 on page 8. This shows there are no fuel sources capable of generating surplus energy comparable to remaining oil reserves. The technical and practicable limits to the alternate resource poten- tials suggests nuclear should form some component of an integrated solution.
Is nuclear energy compatible?
The unsuitability of electricity for many services, the inflexibility of nuclear capacity, and the fragility of renewable energy business models create significant upper capacity limits for nuclear. Nuclear energy produces electricity. Only a small fraction of current UK energy requirement is consumed in the form of electricity. Nuclear’s stringent safety processes impose considerable restrictions on the rate at which supply can vary, limiting its role in the overall energy mix. This inflexibility reduces the flexibility of the system as a whole, impacting other energy sources.
The UK consumes relatively little electricity
This shows UK energy demand by fuel source and application. Only 20% of all consumption is in the form of electricity. 35% of consump- tion is in the form of gas. 40% of all energy consumption of energy is for transportation, 95% of which is supplied by petroleum.[1]
These numbers show that electricity is a relatively small component of the energy mix. While domestic and Industrial gas services such as heating can be converted to electricity, there is limited scope for the conversion of transportation to electricity. Nuclear energy (or indeed any non-hydrocarbon energy source) therefore cannot be relied upon to meet the UK’s energy re- quirements by itself.
Nuclear cannot deliver all of UK’s electricity requirements
This shows UK daily electricity consumption for 2008. Summer base load is around 24GW and peaks at 35GW. Winter baseload is nearer 32GW peaking at 58GW.
Nuclear power stations require around 24 hours to be taken offline or reinstated after shutdown. They can therefore only efficiently provide baseload duty, with summer demand baseload defining the maximum efficient nuclear generating capacity. A realistic maximum for nuclear capacity in the UK would be approximately 24GW. Additional capacity would result in efficiency reductions associated with offline plant during summer months.
Nuclear damages fragile renewable capacity business models
Wind generation is characterised by intermittent availability and uncontrollable generation peaks. High levels of nuclear capacity create significant problems for such sources. Cyclic electricity demand fluctuation would result in frequent disconnection of wind turbines, particularly at night, to prevent over supply to the grid. This would severely impact wind generation business models.
Is nuclear energy operable?
The safe running of nuclear facilities and the disposal of waste are solvable technical issues under stable conditions. Serious risk emerges under conditions of societal and international instability. Nuclear technology’s image amongst opponents as a dangerous activity is not supported by accident statistics. With proper skills, operations and mainte- nance practices and materials, operational and disposal risks are controllable. These cannot be assumed in the unstable conditions that would arise during international conflict over energy resources and societal stresses during supply interruptions.
There have been no fatalities outside the former Soviet Union
There have been 12,700 reactor-years of civil operation of nuclear power gener- ation in 32 countries. In that period, there have been two major accidents– Three Mile Island in the US, and Chernobyl in the Former Soviet Union. Chernobyl is the only incident in which fatalities amongst nuclear workers and members of the public has occurred.[10] The design, operating methodology and safety standards of Chernobyl were significantly poorer than those that would be achievable in the UK. Three Mile Island served to prove that even a catastrophic meltdown does not result in large scale release of contamination. Nuclear design has advanced considerably since then to ensure that contaminants are not mobilised beyond the immediate internal structure in the event of catastrophic failure. There is therefore little ground for rejecting nuclear technology on safety grounds, under stable conditions.
Nuclear technology requires complex social organisation
The byproducts of the industry are persistent radioactive poisons and mate- rials for bomb making. Integrity of the system must be maintained during transportation, storage, conversion and disposal in power, industrial, medical and military facilities. These facilities are vulnerable to military and terrorist attack, particularly from the air. One U.S. Department of Energy study assesses the implications of unmet shortfalls in oil supplies on the world economy. The impact will be severe, with large increases in inflation and unemployment, declines in the output of goods and service and a degradation of living standards.[5] Controlling nuclear risks requires financial resources, a strong central authority and international stability and cooperation. Under the conditions forecast in the U.S. Government report, the complex social organization needed to run nuclear energy safely cannot be assumed.[7]
Is nuclear energy sustainable?
Fuel supply constraints in primary and secondary fuel sources for current technology mean that a substantial increase of nuclear energy based on that technology is essentially impossible. Nuclear energy is the product of a long sequence of activities, each stage of which is energy intensive and becomes more so as ore quality decreases. Both the hydrocarbon fuel used to power the chain and the chemicals used in processing are greenhouse gases.
The global uranium supply situation is deteriorating
The current global nuclear power resource base comprises 436 reactors in 30 countries, generating 2,600 TWhe of electrical energy in 2008. This consumes 65,000 tonnes of Uranium per year, derived from both primary and secondary sources.[6] Around 60% is obtained from uranium mines with the rest coming from other sources including waste processing and decommissioned nuclear weapons. Supplies from both sources are constrained. Forecasts of future supplies of uranium from a study performed by the World Information Service on Energy projects shows an increasing gap in fuel supply, even before the energy considerations of front-end and back-end processes are considered.[9]
Nuclear production is energy intensive
Despite very high energy densities available from concentrated fuel, the “front end” processes required to extract and refine the fuel to such concentrations are themselves energy intensive. Most shallow deposits have been discovered and deep deposits require the removal of massive overburden. Water is required in large quantities in some parts of the process, and removed in others. Front-end processes typically account for around 25% of the gross energy output. As can be seen in Table 1.1 on page 8, the end result is a low practical return on energy invested.[4]
Nuclear waste disposal is energy intensive
Equally, the “back end” processes–disposing of old reactors and clearing up current waste–account for around 25%. However, a proper analysis must include the energy requirement of processing the backlog of waste which has accumulated since the start of the industry in the 1950s. When this is taken into account, the entire net output of remaining fuel reserves will be required to convert those reserves and dispose of stockpiled wastes, leaving no energy left over for useful work.
Conclusion: Is nuclear energy a Good Idea?
Nuclear energy is popularly presented by its supporters as capable of safely providing abundant quantities of clean, high quality electrical energy. In 50 years of commercial operations, the industry has maintained an excellent safety record and does make a notable contribution to the energy mix in a number of countries. The seriousness of the impending energy crisis and lack of clear alternatives provides considerable incentive for increasing investments and effort to overcome some of the technology’s shortcomings. However. The energy source is fundamentally incompatible both with important types of consumption in society and with alternative energy technologies. Its complexity and the serious consequences of failure make organisational demands that cannot be guaranteed as the energy crisis deepens. Most seriously, the technology is itself such a large consumer of energy over the full life-cycle that it is incapable of generating a positive return on energy investment (ROEI). It may be possible that so-called 4th generation technologies are capable of improving ROEI’s. However, credible estimates predict that such technologies will not be developed for a further 20 years, by which time the energy gap will likely have deepened to the point where such technologies may not be constructable.
Given the scarcity of financial and human resource necessary to develop replacement energy technologies, this essay concludes that nuclear energy is NOT a Good Idea.
References:
- Uk energy in brief july 2008. National Statistics, pages 1-40, Jul 2008.
- C Cleveland, R Costanza, and C Hall. Energy and the us economy: abiophysical perspective. Science, 225(4665):890-897, Jan 1984.
- EIA. International energy outlook (2009). Annual Report, pages 1-284, May 2009.
- David Fleming. The LEAN Guide to Nuclear Energy. The LEAN Economy Connection, November 2007.
- Robert L. Hirsch. Peaking of world production: impacts, mitigation and risk managment. Technical report, SAIC, 2005.
- IEAE. Uranium: Resources, Production and Demand (The RedBook). International Atomic Energy Agency, 2008.
- James Howard Kunstler. The Long Emergency. Atlantic Books, 2006.
- M Smith. Filling the oil supply gap. Petroleum review, Jan 2007.
- WISE. Uranium supply and demand. Technical report, World Information Service on Energy, 2009.
- WNA. Safety of Nuclear Power Reactors. World Nuclear Association, 2008.