At first glance, nuclear energy seems like a great alternative to burning fossil fuels. It is a cleaner and more efficient source of energy, which does not cause global warming or acid rain. U.S. nuclear reactors rely on uranium, which is naturally abundant locally, so nuclear power reduces dependence on foreign energy. However, while some argue that nuclear power plants are as safe as any other energy production, the radioactive waste produced and nuclear accidents like Three Mile Island are evidence that alternative options should be explored. According to Sandra Alters, nuclear reactors work like this: Fuel rods, made of zirconium, with fissile fuel pellets (uranium in the US) are assembled into bundles in the reactor core. They are surrounded by control rods, made of iron, cadmium, indium or silver, which absorb or capture neutrons to slow the reaction. Neutron moderation is also important because neutrons must be slowed down so that the atomic nucleus can capture them. Through the process of fission, i.e. the splitting of the uranium nucleus into smaller fragments by bombardment with neutrons, heat is produced. In a pressurized water reactor (PWR) this heat circulates in a tank of radioactive water, which transfers its heat to a second tank of steam-producing water, which flows through a turbine and turns the generator, transforming the energy mechanics into electrical energy. Uranium-235 is the ideal fuel, because it is easily available and reactions with it release neutrons that continue the changing reaction. However, uranium straight from the ground is 98% uranium-238, which must be enriched to at least 5% uranium-235 for fission to occur. Additional challenges include maintaining a critical mass, or the amount of fissile material required… middle of paper… ear power needs to be rethought. References Alters, Sandra M. (2009). Nuclear energy. Opposing points of view in context. doi:GALE|EJ3020670105 Canadian Nuclear Association. (2012). Nuclear Facts: Is nuclear energy a good choice for the environment? Retrieved from http://www.cna.ca/nuclear_facts/nuclear_environment/Environmental Protection Agency (n.d.) Gamma rays. Retrieved from http://www.epa. gov/radiation/understand/gamma.html Freudenrich, Craig. (nd) How nuclear fusion reactors work. Retrieved from http://science.howstuffworks.com/fusion-reactor.htmGreenpeace. (nd) Radioactive waste. Retrieved from http://www.greenpeace.org/usa/en/campaigns/nuclear/safety-and-security/radioactive-waste/Pressurized Water Reactor [Image online]. Retrieved January 20, 2014, from http://www.nrc.gov/reading-rm/doc-collections/nuregs/brochures/br0164/r5/br0164r5.pdf