2. Chapter 17, Section 2: Nuclear Energy Standards: SEV4a, e

3.  Nuclear energy is the energy within the nucleus of an atom.  This energy is very powerful & can be harnessed thru fission reactions.  Uranium is the element used as a source of nuclear energy.

4.  Neutrons are fired into atoms of uranium.  Uranium atoms split & release their neutrons and tons of energy.  These uranium neutrons go on to split more uranium atoms  This creates a chain reaction  Chain reaction of energy can easily get out of control and cause explosion.  Constant monitoring and safety measures must be taken to prevent explosions.

5.  A nuclear reactor is a large concrete structure that houses the uranium fuel assembly. Has concrete walls that are 30 cm thick with steel inner lining to contain potential explosions. Has large vat of water that has uranium fuel rods submerged in it. Vat of water also contains control rods.  Control rods of cadmium or boron absorb neutrons and control the uranium chain reaction.  Uranium chain reaction occurs, heats water, creates steam, turns turbine which turns a generator to create electricity

6.  Water absorbs heat and slows the neutrons.  Control rods control the rate of the reaction. During peak energy demands control rods are raised out of water so reaction can happen faster and create more energy. During nonpeak periods control rods are submerged to slow the reaction. If reaction appears to get out of control, the control rods are slammed into the reactor vessel to stop the reaction.

8.  Pros Energy is highly concentrated- a little goes a long way so it will last longer than fossil fuel. Does not produce greenhouse gases Good for countries that do not have good supply of fossil fuel  Ex: France- 75% of its energy comes from nuclear power  Cons Uranium is nonrenewable VERY EXPENSIVE  Natural gas plant = $600/kilowatt (kw)  Wind power = $1000/kw  Nuclear power = $3000/kw Low net energy yield because so much energy goes into mining, processing, safety, etc. Must have complex buildings and extensive safety equipment Nuclear waste is VERY DANGEROUS

9.  Nuclear waste consists of used fuel rods, water, mining waste, & clothing of workers.  Exposure can cause cancers or tumors  Radioactive for 1000’s of years  Must have container to store it in that will last that long.  Currently most radioactive nuclear waste is stored onsite in huge concrete vaults underground.  A site at Yucca Mtn, Nevada is being developed to house all nuclear waste Many people do not want waste traveling thru their towns to Nevada New containers have been developed to prevent risk of nuclear waste accidents during travel. Do you think it is safe to store all radioactive waste in one location?

16.  Site must be Away from people Away from water source Geologically stable- no earthquakes  As of April 2011, government funding for Yucca Mtn facility has been suspended.

17.  When the chain reaction gets so out of control it causes an explosion  Worst nuclear accident was in 1986 in Chernobyl in the Ukraine. Workers turned off safety devices to conduct an unauthorized test. Entire city evacuated To this day very high radioactive levels in the area. Caused human, animal, & plant mutations as well as numerous types of cancer. Mutated tree. Notice the inner part of the limbs are green (before explosion) & outer parts are blue (after explosion)

18.  2 new nuclear power plants have been approved for Georgia.  Located south of Augusta

19.  Nuclear fusion- combining of nuclei to make heavier atom and releases large amounts of energy.  Same energy as in sun & stars  Safer only b/c less dangerous radioactive byproducts  Technology not developed yet to harness power safely.