Everyone. Today the world uses a great deal of energy and the usage is increasing dramatically in developing countries.

In the early 1970s a fourfold increase in the price of oil alerted the world to the need for more efficient use of energy.

In OECD* countries the response to this, including greater use of electricity, led to a levelling off in demand for primary energy. Between 1973 and 1985 primary energy demand in the OECD remained unchanged despite an increase in gross domestic product (GDP) of 33%. Since 1985 energy use has been rising again.

* Organisation for Economic Cooperation and Development

Outside the OECD countries the picture is different, and primary energy demand is increasing by about 50% each decade. Overall, world energy demand is expected to increase by 57% from 1997 to 2020.

Any attempt to understand or forecast global energy requirements must take account of population growth. At the beginning of the twentieth century, world population was about 1.5 billion. Today it is 6 billion and growing at the rate of 90 million a year. By the year 2025 world population is expected to reach 8 billion.

Over 90% of world population growth in the foreseeable future will be in the less developed countries, which already contain 75% of the world's people. United Nations projections show most of this growth taking place in urban areas.

Even with effective energy efficiency programs in developed countries there will be a global need for much more energy if people in the less developed countries are to improve their standards of living. A large part of this increase will be in electricity.

For instance, the growth in demand for primary energy in East Asia to 2010 is likely to be 5% per year, and that for electricity 7-8% per year. In China, power generation requirements are expected to almost double from 1994 to 2010, with much of this being nuclear. China has ten reactors definitely planned or under construction, with three already in operation.

The Role of Electricity

Electricity is the most widely used and rapidly growing form of secondary energy use. Its generation accounts for about 40% of total primary energy supply. It offers great flexibility of distribution and use, is relatively efficient, very safe for the consumer, and environmentally benign in end-use.

Although overall energy intensity (energy per unit of GDP) fell 25% worldwide 1971 to 1997, electricity demand increased almost threefold over this period. From 1973 to 1998 the proportion of total energy consumed as electricity in OECD countries grew from 12% to 19% and it is expected to reach 23% by 2010.

All energy conservation scenarios assume the expanded use of electricity. The most important fuel for generating electricity is coal which provides 39% of all electricity generated. Uranium used in nuclear power stations today provides 16% of the growing total.

During the decade 1988-98 electricity production in the major geographic regions and the world grew as follows:

Electricity Production: Billion Kilowatt Hours (TWh)   1988 1998 Increase   OECD 7035 9125 30% non-OECD 4037 5278 31% World 11072 14403 30% non OECD: former USSR 1705 1224 -28% Africa 303 416 37% Latin America 467 718 54% Asia(exc. China) 546 1107 103% China 571 1197 110% Middle East 212v410 93%   Source: OECD/IEA 2000, Energy Statistics of Non-OECD countries, 1997-98.

There is a wide consensus that world electricity demand will double from mid 1990s levels by 2020, with demand growing at 2.7% per year.

In 1999 production of electricity in the OECD by the fuel used was:

Worldwide in 1998 the picture was similar: coal provided 38% of electricity, nuclear 17%, gas 16%, oil 9%, and hydro & other 20%.

There is more electricity generated by nuclear power today than from all sources worldwide in 1961 (2448 billion kWh in 2000).

Electricity and Greenhouse

There is no form of energy conversion, such as turning primary energy into electricity, without some environmental implications.

In recent years attention has been focused on the climate change effects of burning fossil fuels, especially coal, due to the carbon dioxide which this releases into the atmosphere.

Carbon dioxide contributes about half of the human-induced increase in the greenhouse effect. Electricity generation is one of the major sources of this carbon dioxide, giving rise to about one quarter of it, or some 9% of the human-induced greenhouse increase.

Coal-fired electricity generation gives rise to nearly twice as much carbon dioxide as natural gas per unit of power, but hydro and nuclear do not directly contribute any. If all the world's nuclear power were replaced by coal-fired power, emissions from electricity generation would rise by a third.

Conversely, there is scope for reducing coal's carbon dioxide contribution to the greenhouse effect by substituting natural gas or nuclear power, and by increasing the efficiency of coal-fired generation itself, a process which is well under way. Nuclear power is well suited to meeting the demand for continuous, reliable supply on a large scale (ie base-load electricity), the major part of demand.

At the time of the oil shock in 1974 France was heavily dependent on overseas supplies of energy. Since then it has built 60 nuclear reactors in a major program. Nuclear power now provides 78% of its electricity, it has become a major exporter of electricity (77 billion kWh in 2000), and it now has a high level of energy independence. Moreover the cost of electricity has declined markedly and per capita carbon dioxide emissions are half those of its neighbours. One neighbour, Italy, is the only industrialised European country without its own nuclear power, but it is also the main electricity importer, - mostly from France.

Fuel Consumed

A 1,000 megawatt electrical (MWe) coal-fired power station burning coal has a typical fuel requirement of almost 3.2 million tonnes* of black coal a year.

*at 24 MJ/kg and operating at 80% capacity. Burning brown coal at 8.15 MJ/kg would require 9.3 million tonnes of it.

A nuclear power reactor of the same capacity, (after its initial fuel loading of uranium), has an annual requirement of around 27 tonnes of fuel. Producing this amount of uranium requires the mining of 45-70,000 tonnes of typical Australian uranium ore (or considerably less of the high-grade Canadian ore). This yields about 200 tonnes of uranium oxide concentrate which is sold, the rest stays at the mine, as tailings. The uranium oxide is enriched to yield the 27 tonnes of actual fuel (see The Nuclear Fuel Cycle in this series).

Coal-fired power stations worldwide consume over 2500 million tonnes of coal each year to produce 38% of the electricity. This compares with about 61,000 tonnes of natural uranium (72,000 t of oxide concentrate from the mines) providing the fuel for the nuclear power stations which provide almost 17% of the world's electricity. Much of the coal is used in the country in which it is mined, but often it has to be transported long distances, which requires considerable energy (and results in further greenhouse gas emissions). Nuclear fuel by comparison is extremely modest in volume and if necessary can even be transported by aircraft. A 1000 MWe nuclear power station requires one truck-load delivery of enriched fuel per month, or an average of about 74 kg per day, which would fit in a small briefcase. An equivalent sized coal-fired station needs some 8600 tonnes of coal to be delivered every day.

Wastes

Emissions of carbon dioxide from burning fossil fuels are about 20,000 million tonnes a year worldwide, of which around 45% comes from coal and 40% from oil.

Each year the 1,000 MWe coal-fired power station produces about 7 million tonnes of carbon dioxide, perhaps 200 000 tonnes of sulfur dioxide (depending on the particular coal) and typically about 200 000 tonnes of solids, mostly flyash. The ash contains several hundred tonnes of toxic heavy metals including arsenic, cadmium, lead, vanadium and mercury which remain toxic forever. If brown coal is used the carbon dioxide figure is about 9 million tonnes.

Methods exist for removing sulfur dioxide and nitrous oxide although the cost is high. Flyash is generally captured and dumped in landfill. However there is no economically feasible way to remove or reduce carbon dioxide from the burning of coal. None of these emissions occur at a nuclear power station, where virtually all wastes are contained in the spent fuel and not released to the environment.

The combustion of coal may also release radioactive heavy metals (including uranium and thorium) contained in it, though these are mostly retained in the flyash. The use of natural gas releases radioactive radon. The amount of radioactivity released is negligible relative to the natural background radiation levels, but is often greater than that from nuclear power generation.

If the electricity produced worldwide by nuclear reactors each year were generated instead by burning coal, an additional 2400 million tonnes of carbon dioxide would be released into the atmosphere. This can be compared with the target of a 5% reduction (600 million tonnes per year) in carbon dioxide by the year 2010, as agreed in 1997 at Kyoto just for the developed countries.

Every 22 tonnes of uranium used avoids the emission of one million tonnes of carbon dioxide, relative to coal. When the electricity comes from coal (as most of Australia's does), every kilowatt hour of it results in about a kilogram of carbon dioxide being emitted.

Borosilicate glass from the first waste vitrification plant in UK in the 1960s. This block contains material chemically identical to high-level waste from reprocessing. A piece this size would contain the total high-level waste arising from nuclear electricity generation for one person throughout a normal lifetime.

The total amount of spent fuel resulting from operation of all the world's commercial nuclear power stations is about 14,000 tonnes per year. About two thirds of this is treated as waste, the rest is reprocessed to recover useful fuel material. By reprocessing the spent fuel, the amount is reduced to about 3% high-level radioactive waste, with the balance being recycled as fresh fuel.

Handling and treatment of these radioactive wastes has been undertaken in many countries for several decades without incident. Nuclear power is the only energy-producing industry which takes full responsibility for all its wastes and costs this into the product.

The spent nuclear fuel elements or the high level wastes are stored for up to 50 years to allow for the decay of most of the radioactivity and heat (to about 0.1% of that when removed from the reactor) before final disposal. Today the waste disposal issue is not a technical problem but one of public and political acceptance.

The Role of Renewables

Renewable energy sources for electricity are diverse, from solar, tidal and wave energy to hydro, geothermal and biomass-based power generation. Apart from hydro power in the few places where it is very plentiful, none of these is suitable, intrinsically or economically, for large-scale base-load power generation.

Because of their diffuse nature (making them difficult to harness efficiently) and their intermittent availability (giving rise to the need for storage or back-up from other sources), their role in meeting electricity demand on any significant scale will always be limited. A 20% contribution to grid supply is the maximum conceivable for non-hydro sources. Renewables have most appeal where demand can accommodate small-scale, intermittent supply of electricity.

Conclusion

All of the various means of generating electricity have a role to play in meeting the rapidly increasing demand for this form of energy. Fossil fuels, particularly coal and gas, will remain important. Nuclear electricity is one part of the solution of the energy equation for today and tomorrow, particularly in the light of concerns about carbon dioxide emissions.

Without nuclear power the world would have to rely almost entirely on fossil fuels, especially coal, to meet electricity demands for base-load electricity production. This has significant environmental, and particularly greenhouse gas, implications.

Nuclear power plants do not emit any carbon dioxide, nor any sulfur dioxide or nitrogen oxides. Their wastes end up as solids and, though requiring careful handling, are very much less than the wastes from burning coal.

Whenever new electricity generating capacity is required or old fossil-fuelled plants need to be replaced it is therefore sensible to consider nuclear as a serious option. Nuclear electricity has accumulated some 10,000 reactor-years of operating experience.

The continued and expanded use of nuclear power is one among a range of measures which will effectively limit future global carbon dioxide emissions. Some 35 countries have chosen nuclear power as part of their energy mix. They have well over 400 power station reactors in operation and more under construction.

Glossary

Primary energy: that obtained directly from primary sources, eg coal, oil, natural gas, uranium, hydro and solar energy.

Secondary energy: that produced by conversion or transformation of primary energy or of another secondary form of energy, eg electricity, steam, hydrogen, refined petroleum products.

Base-load electricity: that part of electricity demand that is continuous and requires reliability.

OECD countries: Australia, Austria, Belgium, Canada, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Japan, South Korea, Luxembourg, Mexico, Netherlands, New Zealand, Norway, Poland, Portugal. Spain, Sweden, Switzerland, Turkey, United Kingdom, USA.

Gross Domestic Product (GDP): the total value of goods and services produced in a country or group of countries within a given period of time, after deducting the cost of goods and services in the process of production.

Spent fuel: nuclear fuel which has reached the end of its useful life in a reactor after about 3 years and has been removed from the reactor.

Updated in June 2001

http://www.world-nuclear.org/education/ueg.htm