Everyone wants electricity. We use it all the time in our homes, schools, hospitals and workplaces. But how many people think about how electricity is made?
One way electricity is created is through nuclear power, which harnesses the energy released from splitting atoms, usually of uranium. The large amounts of heat released in nuclear reactions are used to create steam that drives the turbines to generate power. The world's first nuclear power station was opened in the UK in 1956 at Calder Hall in Cumbria, and there are now several hundred reactors in operation around the world.
But nuclear power is very risky. Major accidents such as Windscale (UK, 1957), Three Mile Island, (USA, 1979), and most dramatically at Chernobyl (Ukraine, 1986) demonstrate what can happen when reactors get out of control. Moreover, nuclear generation creates dangerous and long lasting radioactive wastes for which there is no safe disposal method.
The early growth of nuclear power in past decades has now stalled. This is for economic as well as environmental reasons. But with existing reactors soon to reach the end of their lives, and with the parallel threat of climate change caused by the burning of fossil fuels, society has to choose how it will generate electrical power in the future.
Environmental groups like Greenpeace argue nuclear power must be consigned to the history books and that we should instead support a much greater use of renewable energy.
Nuclear waste management
One of the main problems with nuclear power is that it gives rise to dangerous and long-lived radioactive waste. Nobody had demonstrated a 'solution' to this waste, despite many decades of trying.
Nuclear fuel inside reactors needs replacing every few years. This 'spent' nuclear fuel, or SNF, when removed is highly dangerous. Handling it directly would kill in a very short time, and so it is usually handled behind steel and concrete shielding. In the UK nearly all SNF is sent - using special trains with 70 tonne flasks - to the Sellafield complex in Cumbria for 'reprocessing'.
Even after spent fuel is removed, the reactor buildings themselves are still contaminated with radioactivity. They are therefore very difficult and expensive to decommission after the end of their operational life. The nuclear industry says it will take more than 100 years to dismantle reactors. Britain's current nuclear clean-up bill, excluding military facilities, is in excess of £50 billion.
If radioactive waste were to be disposed of, it would over time leak back into the environment. With underground burial, for example, flows of ground water would bring dissolved radioactive particles back to the surface. Nuclear waste must therefore be stored indefinitely in managed, monitorable and retrievable stores.
The Government's policy on radioactive waste management has remained vague since a plan to bury most of the UK's waste collapsed in 1997. Environmentalists argue that, as there is no solution to radioactive waste, society should stop making more of it by rapidly phasing out nuclear power.
The problem of radioactive waste has led some countries to try to 'recycle' spent nuclear fuel (SNF) by 'reprocessing' it. Reprocessing involves the chemical separation of SNF by dissolving it in nitric acid. This allows some of the component parts to be recovered and potentially reused (although in practice little is reused). It is a messy process as it leads to the creation of yet more radioactive waste and discharges into the sea and air.
There are only two major reprocessing facilities in the world. Sellafield in Cumbria in the UK, and La Hague in Normandy in France. These factories reprocess SNF from other countries such as Germany and Japan. This international trade in nuclear waste creates additional risks from the trains and ships that carry the material. En-route states and communities such as Chile and South Africa have objected to radioactive waste ships passing close to their countries.
Reprocessing is more expensive than storing spent nuclear fuel and so most nuclear operators avoid it, preferring to put spent nuclear fuel into long-term storage. Sellafield's biggest customer - British Energy, which currently generates about a quarter of the UK's electricity - wants to end reprocessing. Germany has said it will stop reprocessing in 2005 when existing contracts expire.
Reprocessing also gives direct access to plutonium, a by-product of nuclear generation. Plutonium is used in nuclear weapons. There are serious risks of civil plutonium stockpiles being diverted for military or even terrorist use. Because of these risks, the industry routinely uses armed security guards to try to protect nuclear sites and shipments that contain plutonium.
Discharge of Radioactivity
The nuclear industry routinely discharges radioactivity into the environment. Radioactivity can lead to cancer. There is no safe dose of radioactivity, and whilst the industry's emissions have fallen in recent years, there can be no guarantee that any radioactive discharges will not cause harm.
Discharges from the Sellafield reprocessing complex into the Irish Sea have been detected as far away as Canada. The contamination of European waters has drawn strong protests from countries such as Ireland and Norway. Ireland is so concerned about both discharges and the possibility of a major accident at Sellafield that it has called on the UK to close down the plant as soon as possible.
Making Choices for the Future
In the European Union, eight out of fifteen countries have nuclear power. However five of those are now pursuing nuclear phase-out policies. Only three - Britain, France and Finland - intend to keep the nuclear option open. Britain and France in particular are seen as 'the dirty men of Europe' for continuing to discharge radioactivity from reprocessing into the sea.
Electricity itself is of course still important and we still need to provide for it. Most electricity still comes from fossil fuels such as coal, oil and gas. But these sources must be limited because of their contribution to climate change and global warming.
The future must lie with renewable energy sources and energy conservation. Wind power, for example, is now the world's fastest growing source on energy. Not only is wind a clean source of energy, the improvements in the technology mean it is now one of the most cost competitive ways to generate large volumes of power. The world's largest wind farm (to date) has recently been proposed on the Isle of Lewis in Scotland. Its 700MW capacity will be greater than the 200MW of the Calder Hall nuclear station mentioned earlier.
A recent change to the way the electricity market works allows people to choose their electricity supplier and the type of tariff they buy. Many utility companies now offer 'green' tariffs that are directly linked to renewable energy sources. By switching to such a power supply - as easy as picking up the phone - individuals can take a simple action that avoids nuclear energy and fossil fuels.
- Mark Johnston's column was written and published in 2006. It originally gave the date of the Three Mile Island nuclear accident as 1980; this has been corrected to reflect the actual date of the partial meltdown, which started on March 28th, 1979.