1. Nuclear energy Summary of period 1

2. Parts of the atom Mass (A.M.U)Charge Proton1+1 Neutron10 Electron1/1830 Add/subtract a proton: creates a different atom Add/subtract a neutron: creates a different isotope Add/subtract an electron: changes oxidation state / creates ion

3. Isotopes Mass number (protons + neutrons) Atomic number (number of protons) Element symbol The isotope of uranium above has 92 protons It has 143 neutrons U-238 has 92p and 146n

4. Isotopes of hydrogen 3 forms of hydrogen: Protium, deuterium, tritium Differ only in the number of neutrons they have Diagram from Microsoft Encarta

5. Fission and Fusion Typical output of chemical reaction ~ 10 eV per atom Output of nuclear fission reaction ~ 3.2 MeV per atom Output of nuclear fusion reaction ~ 200 MeV per atom The energy outputs of nuclear rxns are massive compared to the output of a chemical reaction, like burning HC fuels Possible advantages: Lower mass of fuel needed Less atmospheric emissions

6. Fusion & Fission Fusion: collision of two nuclei to make a new nucleus, e.g. two deuterium atoms fuse to make a helium-3 nucleus, emission of a neutron and released energy Fission: neutron collides with large, unstable nucleus causing it to break into smaller fragments. In ex. Shown, two neutrons emitted which may collide with two more U-235 nuclei – chain reaction Illustration from Microsoft Encarta

7. Fusion & Fission Fusion reactions – usu. Small stable nuclei Fission reactions – usu. Large, unstable nuclei Natural abundance of U-235 is very low (~ 0.7%) Not enough to ensure stray neutrons collide with them and give a sustained nuclear reaction (critical mass) Fuel enrichment is required (next period – the nuclear fuel cycle)

8. The pressurized water reactor Make sure you can label this or a similar diagram Be able to describe the operation of the reactor Why are PWR’s generally located by a lake, river or the sea?

9. Location, location, location… The nuclear pwr station need not damage local ecology

10. The San Onofre reactor

11. Cooling Volumes of steam are released after work has been done on the turbines. Is this efficient use of all that energy?

12. The reactor core The long object is a boron control rod that is being removed for maintenance

13. The turbine floor These are the turbines that turn the generator to make electricity

14. Next Period The Nuclear Debate Arguments for Arguments against