electricity generation » nuclear power - Overview of nuclear energy and the debate surrounding its use.

Nuclear Power

Controversial yet consistently relied upon for providing large volumes of electricity; nuclear power has its fair share of both supporters and critics. Many believe that the incredible amounts of energy generated through the nuclear fission process (splitting atoms to release energy) is outweighed by the potential hazards of the technology - nuclear waste is extremely radioactive and is harmful to humans and the surrounding environment.

Because of the incredible heat generated by fission, nuclear reactors risk having what is known as a melt-down. Melt-downs occur when the heat inside the reactor exceeds the capacity of the surrounding structure, causing an explosion such as that which occurred at the Chernobyl site in Ukraine in the 1980s. The waste product of the fission process is also very difficult to dispose of safely, with waste products remaining radioactive for thousands of years. Yet supporters claim that recent improvements in safety technology and storage philosophies, such as passive nuclear safety and deep geological repository systems, greatly reduce the risks mentioned above.

An Answer To Excess Carbon Emissions?

In recent years governments (including the present government in the United Kingdom) have turned to nuclear power as a suitable source of electricity which has minimal carbon emissions but large outputs of power. Nuclear power is not a permanent solution to the energy crisis, however, as nuclear power is generated from the splitting of uranium atoms (uranium 235) and therefore cannot be called a renewable source of energy. The amount of uranium present in the earth's surface is finite and it is estimated that there is only enough uranium to power all of the world's electricity needs for the next several hundred years.

Research into the use of thorium in the new Generation IV reactors may mean the end of this reliance on uranium, however, with the additional benefits being that thorium is more readily available than uranium and has a much smaller radioactive half-life than uranium waste.

Environmental Concerns

Aside from the reliance on uranium and the risk of radioactive contamination, there are two key problems regarding the nuclear technology which prevent environmental groups from giving the technology their support. One of the key elements of nuclear power production is the use of water for cooling the reactor (this prevents melt-down and is vital to the entire safety system). Whilst some nuclear reactors recycle the water they use (such as the pressurized heavy water reactors) others release it as steam into the atmosphere or into cooling ponds. Not only is there concern over the releasing of warm water back into the water table, but where the water is sourced from can also create problems - if too much water is drawn it can upset the delicate environmental balance of the surrounding area; if there is a drought the lack of supply could cause melt-down.

Long-Term Storage

Aside from the need for water and the subsequent environmental issues, another problem with nuclear power is that the radioactive waste product is impossible to treat or recycle completely. Whilst some reactors have methods for reusing particular elements of the waste product, there is still a large portion of radioactive residue which is essentially unable to be used or treated, and this portion has to be cooled (in water) and then held in dry storage.

At present governments are researching the possibility of the deep geological repository system which would involve the digging of large chambers or caves in geologically stable areas for use as radioactive waste land-fills. While controversial it would appear this is a feasible part of the nuclear future to which humanity may be moving.