To say nuclear power is a contentious issue would be an understatement. While some stress the negative impacts of nuclear power by pointing out the enormously hazardous waste released; while others point to Chernobyl and Three Mile Island disasters – still there are those who praise the technology as a low emissions way to create serious amounts of power.
In this era where it seems the stakes just keep getting higher, nuclear energy has tried to reposition itself as an environmentally friendly option, creating electricity without the emissions or potential nasties of fossil fuels. As of July 2007 there were more than 430 nuclear plants operating worldwide, providing 15 per cent of global electricity.
Power plants that depend on atomic energy don’t operate that differently from a coal fired plant. Both heat water into steam, which drives a turbine generator. The difference between the two plants is the means of heating the water. While some older plants burn fossil fuels, nuclear plants depend on nuclear fission, when one atom splits into two.
The science behind nuclear power
Uranium 238 (U-238) has an extremely long half life of 4.5 billion years (the time it takes for half its atoms to decay). U-238 has been present since the earth formed. Uranium 235 is decayed U-238. It (U-235) makes up about 0.7 percent of the remaining uranium found naturally.
There are few materials that can undergo induced fission but, U-235 is one of them. If a free neutron collides with a U-235 nucleus, the nucleus will absorb the neutron, become unstable and split immediately. A spinoff from this process is plutonium, the most deadly substance known to man.
When talking about nuclear power there is always the holy grail, which is nuclear fusion. Fusion power would supply much more energy for a given weight of fuel than any other technology currently in use. The fuel itself, mostly deuterium, is found abundantly in the earth’s oceans.
About one in 6500 hydrogen atoms in seawater is deuterium. Because nuclear fusion reactions are so much more energetic than chemical combustion; and, because seawater is easier to access and more plentiful than fossil fuels, some energy experts believe that fusion could the supply the worl’d's energy needs for billions of years. At the current rate of progress it is unlikely that we’ll see a commercial fusion reactor until at least 2050.
The advantages of nuclear power
Nuclear power’s biggest advantages are simply that it doesn’t rely on fossil fuels. Natural gas and coal power plants release large amounts of carbon dioxide into the atmosphere, contributing to climate change. Carbon dioxide emissions are minimal with nuclear power plants. In fact a properly functioning nuclear power plant actually releases less radioactivity into the air than a coal fired plant.??
Disadvantages of nuclear power
Nuclear fuel doesn’t produce carbon dioxide, but it does provide a unique set of problems all of its own. Mining and purifying uranium hasn’t always been a very clean process. The transportation of nuclear fuel to and from plants poses a contamination risk.
Once the fuel is spent it is still radioactive and potentially lethal – where to store it has been a large concern and it may be that future generations end up paying for our relatively lax approach. A nuclear power plant generate s 20 metric tons of used nuclear fuel a year. This is classified as high-level radioactive waste. When you multiply this by every known nuclear plant on earth, the combined total rises to 2,000 metric tons yearly. Since all of the waste produces radiation and heat it will eventually corrode through any container and this will prove lethal to nearby life forms.
The plants themselves have shown to have catastrophic consequences when things go wrong. The Chernobyl disaster is a good example. In 1986 the Ukrainian reactor exploded following decisions taken to rectify some relatively lax procedure. 50 tons of radioactive material discharged into the surrounding area, contaminating millions of acres of farmland and forest. The disaster forced the evacuation of tens of thousand of people and eventually caused untold numbers to die from cancer and other illnesses.
Despite being more environmentally friendly in the short term, nuclear power is a high stakes game. You get the benefits of low emissions, but you also face the nasty spectre of a meltdown. What will happen to the nuclear waste is also a big issue. One thing is for certain; it will be good when certain green technologies help wean us off nuclear power, and, by extension, fossil fuels. Then we won’t be having these arguments.
Frontline special “Heat” – Carbon Free Power http://www.pbs.org/wgbh/pages/frontline/heat/view/8.html
‘How Nuclear Power Works” from How Stuff Works http://www.howstuffworks.com/nuclear-power.htm
Nuclear Power, from Wikipedia http://en.wikipedia.org/wiki/Nuclear_power