Nuclear power has a bad reputation. Chernobyl, Three Mile Island, and now Fukushima in Japan bring up the worst fears of tapping atomic energy. However, I feel optimistic about the future of nuclear power generators as a solution to our energy and pollution woes. So does France, apparently, which is generating 77% of its electricity from nuclear power.
Nuclear power plants are, in fact, giant steam engines. Electricity is generated by turbines, turned by steam pressure, which is created from heat caused by nuclear reactions. The reaction in question is fission… when an atom splits in two and a massive amount of energy is released.
The energy potential in 1 gram of uranium is equivalent to 3 tonnes of coal. When an atom absorbs a loose neutron it becomes unstable and splits into two atoms. The splitting releases huge amount of energy, and one to three extra neutrons which will likely find another uranium atom and cause it to repeat the process. If this reaction is left to escalate we have an atomic bomb explosion, but when it is carefully controlled, inside a machine we call the “reactor”, that same power is released in moderation to heat water into steam.
Current nuclear reactors are very picky eaters, only working with one specific isotope of uranium. (an isotope is, essentially, a specific “flavour” of an element depending on the number of neutrons) However, researchers figure that by 2020 new reactors will be in production to harness more power from more common radioactive fuel, boosting efficiency 50 times over. (I’ve heard it said that the fear of nuclear energy has hampered funding for reactor development over the last 50 years, but progress is coming slowly)
Nuclear power reactors themselves generate zero greenhouse emissions, but there are some tiny emissions in the total life-cycle which includes mining uranium and refinement. All in all, nuclear power generates 3.3 grams of CO2 per Kilowatt-Hour of power. Compare that to 400 and 700 grams per KW-Hr for natural gas and coal plants, respectively. These figures come from European energy company Vattenfall, which shows nuclear energy contributing less greenhouse gases than even hydro and wind generated electricity.
Now, the big downside to nuclear power is radioactive waste. It’s not a lot of waste, but it poses some tricky problems. This waste needs to be kept away from the ecosystem for 100,000 years before it will deteriorate to natural radioactivity. Spent fuel, which is a pellet about the size of your fingertip, is first held in a pool of water until the most radioactive particles cool down. That takes about 20 to 40 years. Long term storage takes the material hundreds of meters underground in a time-capsule of radiation containment.
Human engineering has never done anything that has been meant to work for 100,000 years, so this long-term storage does raise many concerns. However, there are examples of radioactive containment happening naturally on earth for the last 1.7 billion years… so that’s a good track record.
My vision of the future doesn’t include flying cars, but it does have a lot of electric cars, and it seems to me that nuclear generated electricity is our best bet for getting ourselves cleaned up.
- Source: Everything you wanted to know about nuclear power – University of Melbourne