Are you prepared?... start 2:27
Renewable or Non-Renewable?
Uranium 92 U C Carbon How many protons? How many electrons? How many neutrons? 92 protons 92 electrons 146 neutrons What is Radiation?
Ionizing vs. non-ionizing radiation
What is Radiation? Radiation = particles or rays given off by unstable atoms. 3 Types: –Alpha ( α) Travels few inches Blocked by paper (skin) –Beta ( β) Travels few feet Blocked by aluminum, glass –Gamma ( γ) Travels far Blocked by lead (steel & concrete).
Don’t forget: You can copy- paste this slide into other presentations, and move or resize the poll.
Background Radiation The amount of radiation we are exposed to daily from the environment Average = 360 millirem/year or 3 millisieverts
EVR3019/Nuclear_Waste.ppt
When people think about nuclear power they think about… 1.Effects of radiation 2.What to do with nuclear waste 3.Nuclear disasters
Genetic damages: from mutations that alter genes defects can become apparent in the next generation Somatic damages: to tissue, such as burns, miscarriages & cancers Effects of Radiation t
Three Mile Island sieverts over 7 days 1,000 sieverts is radiation sickness 5,000 is death %20map&ndsp=20&safe=on&ie=UTF-8&sa=N&tab=il
Chernobyl sieverts per hour 240 acute radiation sickness; 31 died within 3 months 100,000 people evacuated Some claim up to 985,000 deaths due to Chernobyl
Chernobyl Fallout
Japan 0.4 sieverts per hour 70,000 people evacuated 140,000 told to stay inside
Nuclear Energy The energy that exists within the nucleus of an atom. Nuclear Fission = the release of energy from the splitting of atoms! Nuclear Fusion = the combining of two smaller atoms into one larger atom. (happens in the sun)
Nuclear Fission
Nuclear Power Plant 1.a controlled nuclear fission chain reaction 2.heats water 3.produce high-pressure steam 4.that turns turbines 5.which turns generator and creates electricity
437 commercial reactors in 32 countries, producing 17% electricity
Nuclear Energy around the World
Limerick Power Plant, Montgomery County
Nuclear Reactor Where nuclear fission occurs. Surrounded by thick concrete, steel & lead. Blocks all radiation!
Inside the Reactor html#project%3DFUELASSEMBLY0317%26articleTabs%3Dinteractive
Fuel Rods –35,000 – 70,000 fuel rods –3% Uranium-235 pellets –Fission reaction heats up water
Control Rods –absorb extra neutrons –Control the chain reaction
What do all of these nuclear power plants have in common?
Cooling Tower Water taken from river, lake, ocean Used to condense the hot steam back to water, but some is still released as steam. (no CO 2, just water!) Warm water released back into the river –Not radioactive – never touches the uranium! –Thermal pollution
Nuclear waste Power plants produce radioactive wastes –mostly spent fuel rods (3-4 years) –each reactor produces about tons yearly Currently stored in pools on site and then above ground casks –some remain dangerous for tens of thousands of years How should we store this waste?
Yucca Mountain
Options for Waste –Keep onsight –Bury –Shoot into space –Bury in ocean floor –Bury in Antarctica –Change it into harmless or reprocess to make new fuel
Low-Level & High Level Radioactive Waste Emit small amounts of ionizing radiation Stored years 1940 1970: put in steel drums, dumped in ocean (still UK & Pakistan) 1970+: gov’t run landfills Stored for thousands of years Mostly spent fuel rods (240,000 yrs) Safety debate Options: –Keep onsight –Bury –Shoot into space –Bury in ocean floor –Bury in Antarctica –Change it into harmless
Decommissioning Life span of a power plant = years –Parts wear out, Fuel is spent –Plant is shut down Highly radioactive for 240,000 years Must store for 10 times the half-life –What can we do with them?
= time needed for one-half of the nuclei in a radioisotope to decay and emit their radiation to form a stable isotope Half-timeemitted Uranium million yrsalpha, gamma Plutonium 23924,000 yrsalpha, gamma Half-Life t
Three Mile Island sieverts over 7 days Remember 1,000 sieverts is radiation sickness 5,000 is death %20map&ndsp=20&safe=on&ie=UTF-8&sa=N&tab=il
Chernobyl sieverts per hour 240 acute radiation sickness; 31 died within 3 months 100,000 people evacuated Some claim up to 985,000 deaths due to Chernobyl
Chernobyl Fallout
Japan 0.4 sieverts per hour 70,000 people evacuated 140,000 told to stay inside
earch/assetDetail.cfm?guidAssetID=BE0F B49C-7C70-4C56-95F2-B3904BC9077Fhttp://streaming.discoveryeducation.com/s earch/assetDetail.cfm?guidAssetID=BE0F B49C-7C70-4C56-95F2-B3904BC9077F 10 min video on nuclear energy –Fission, fusion, overview
What do you know now? Take the quiz: radiation-quiz.htm radiation-quiz.htm