Nuclear Fusion

1. Nuclear Fusion • Process during which two or more atomic nuclei merge and form one heavier nucleus • Causes the release or absorption of large quantities of energy • Fuels the sun and stars • Used to make hydrogen bombs • Provides a relatively inexpensive alternative energy source for electric-power generation

2. Nuclear Fission • Nuclear reaction that splits the nucleus of an atom into smaller, subatomic particles • Sum of masses of fragments is less than original mass • Releases large amounts of energy as electromagnetic and kinetic energy • Can occur without neutron bombardment (radioactive decay) • Can be used to create a nuclear chain reaction – exponential growth

3. Radioactivity • Emission of energetic particles or waves from atoms • Measured in rads, where one rad represents 0.01 joule of energy absorbed per kilogram of tissue • Observed in the heavy elements, like uranium, and unstable isotopes, like carbon-14 • Three distinct types of radiation – alpha particles (positively charged), beta particles (negatively charged), and gamma rays (neutral) • Physically impossible to predict whether or not a given atomic nucleus will decay and emit radiation at any given moment

4. Advantages of Nuclear Power • Almost no emissions – no pollution into atmosphere • Very Productive – small amount of nuclear power generates large amount of energy • Can be sited almost anywhere (unlike oil which is mostly imported) • New reactor types designed to be physically impossible to melt-down

5. Disadvantages of Nuclear Power • Expensive to build nuclear plant • Waste products are highly dangerous – melt-down would pose safety hazard to people and surroundings • Expensive to clean up spillages • Products from reactors can be stolen and turned into atomic weapons

6. How Radiation is Transmitted • Travels in the form of waves or high-speed particles • Through the air  our noses or mouths (breathing) • Through rain  groundwater (lakes and reservoirs)  drinking water • Through water used to cool off nuclear plants  ocean  marine life (e.g. fish)  food

7. Harmful Effects of Radiation • Hair loss; dry and itchy scalp • Brain damage – seizures and immediate death • Reduction in lymphocyte presence in blood – mild radiation sickness (more susceptible to infection) • Damage to gastrointestinal tract – nausea, bloody vomiting, abdominal pain and diarrhoea • Destruction of the reproductive tract – radiation sterility; birth defects

8. Half-life • Time taken for half of the atoms in a given mass to decay • Equation for half-life: τ = o.693/λ

9. Advice on Radioactivity • Keep a safe distance away from places that have the radioactivity symbol • Eat healthy, iodine-rich foods e.g. sea vegetables, yogurt, fish, shrimp, eggs, and strawberries • Take potassium iodide pills in recommended doses if necessary

10. http://www.atomicarchive.com/Fusion/Fusion1.shtml http://www.universetoday.com/76609/nuclear-fusion/ http://www.atomicarchive.com/Fission/Fission1.shtml http://www.universetoday.com/73600/what-is-nuclear-fission/ http://www.whatisnuclear.com/articles/radioactivity.html http://www.wisegeek.com/what-is-radioactivity.htm http://wiki.answers.com/Q/What_are_advantages_and_disadvantages_of_nuclear_power http://www.nlm.nih.gov/medlineplus/radiationexposure.html http://knowledge.allianz.com/?1436/how-does-radiation-travel http://www.ehow.com/about_5315898_harmful-effects-radiation.html http://www.ndt-ed.org/EducationResources/HighSchool/Radiography/halflife1.htm www.phys.utk.edu/labs/modphys/RadioactiveHalflife.pdf http://www.psychology-advice.net/why-not-to-freak-out-about-radiation-from-japan Bibliography