Do Now:

1. Do Now: How many Joules are required to get from Newburgh to Mahopac? • Newburgh  Mahopac 33 miles • Driver input 6530 BTUs/person/mile • 1 BTU = 1000 (1x103) Joules • 1 kJ = 1000 (1x103) Joules

2. Do Now: ANSWER How many Joules are required to get from Newburgh to Mahopac? • 33 miles X 6530 BTUs/1 person/mile= 2.1x105 BTUs/person • 2.1x105 BTUs/person X 1x103 joules/1 BTU =2.1X108 Joules/person

3. http://www.nrc.gov/ Chapter 11: Nuclear Energy

4. Nuclear Energy • In contrast to a chemical reaction, a nuclear reaction involves changes within the nuclei of an atom.

5. Atomic Structure

6. Structure of an atom & chemical energy

7. Structure of an atom & chemical energy

8. Valence Electrons http://www.Chemicool Periodic Tablechemicool.com/

9. Nuclear Energy • Small amounts of matter = large amounts of energy.

10. Nuclear Energy Nuclear reactions produce 100,000 times more energy per atom than chemical reactions. http://www.atomicarchive.com/Movies/index_movies.shtml

11. Nuclear weaponry releases this energy all at once. A 23 kiloton tower shot called BADGER, fired on April 18, 1953 at the Nevada Test Site, as part of the Operation Upshot-Knotholenuclear test series.

12. The 1945 TRINITY nuclear explosion. • May 7, 1945 • The first nuclear explosion in history took place in New Mexico, at the Alamogordo Test Range, on the Jornada del Muerto (Journey of Death) desert, in the test named Trinity. • The heat of the Trinity explosion melted the sandy soil around the tower to form a glassy crust known as "trinitite".

13. The 1945 TRINITY nuclear explosion.

14. Nuclear Energy Nuclear energy plants control the rate of the energy released.

15. Isotopes of Hydrogen • Deuterium: 1 proton and 1 neutron (hydrogen usually has no neutrons). http://www.purchon.com/chemistry/atoms.htm

16. Tritium: 1 proton and 2 neutrons. (Radioisotope of Hydrogen) Isotopes of Hydrogen

17. Radio Isotopes • These are unstable isotopes and are referred to as radioactive. • They spontaneously emit radiation.

18. Radiation: particles or rays of energy that result from the decay of a nucleus of a particular element into that of another element.

19. Radioactive Decay • Uranium 235 (U 235) decays into Lead 207 (Pb 207) http://www.chemicool.com/

20. Radioactive Half-Life • The period of time required for one half of the total amount of a radioactive substance to change into a different element.

21. Nuclear Fuel Cycle • The processes involved in producing the fuel used in nuclear reactors (Uranium ore) and in disposing of radioactive wastes. (nuclear waste)

22. Nuclear Fuel Cycle Not taking place

23. Uranium ore needs to be refined through enrichment to obtain approximately 3% U 235Uranium ore has approximately: 0.71 % U 2350.01 % U 23499.0 % U 238

24. Nuclear Reactors • Uranium pellets are used to obtain energy (uranium dioxide.) • Each pellet is equivalent to the energy found in a ton of coal (2000 1bs). http://www.peakoil.org.au/nuclear.co2.htm

25. Uranium Enrichment • To make fuel for reactors, the natural uranium is enriched to increase the concentration of U235 to 3 percent to 5 percent. • The uranium fuel cycle begins by mining and milling uranium ore to produce Triuranium octaoxide (U3O8), also known as "yellow cake," which is then converted into uranium hexafluoride (UF6). • The UF6 is then enriched before being made into nuclear fuel. • Throughout the global nuclear industry, uranium is enriched by one of two methods: • gaseous diffusion • gas centrifuge • A third method – laser enrichment – has been proposed for use in the United States. http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/enrichment.html

26. Nuclear Fuel Cycle • Pellets are inserted into fuel rods (12 ft long) which are grouped into fuel assemblies (200 rods/assembly)

27. Do Now:Identify the following reactions • 4 1n + 127 I  131 I ____________ (atomic #53 iodine) 2. 238U  234 Th + 4 He___________ • 234 Th  234Pr + e ____________ (atomic #59 praseodymium) 4. 1n + 235Ur  97 Kr + 141 Ba 3 1n __________ 5. 2H + 2H  4He ____________ http://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=

28. Do Now: ANSWERSIdentify the following reactions • 4 1n + 127 I  131 I Neutron capture (atomic #53 iodine) 2. 238U  234 Th + 4 HeAlpha Decay • 234 Th  234Pr + e Beta decay • 1n + 235Ur  97 Kr + 141 Ba 3 1nFission • 5. 2H + 2H  4He Fusion http://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=

29. Nuclear Reactors • Most reactors contain 250 assemblies. • U235 is bombarded with neutrons which causes a fission reaction (splitting) of the nucleus.

30. Nuclear Reactors • This initial splitting frees up additional neutrons which then bombard more U 235 nuclei which frees more neutrons which splits more U 235 nuclei... • This is called a chain reaction or “cascade effect.”

31. Nuclear Fission http://www.atomicarchive.com/Movies/Movies/chainreaction.mov

32. Nuclear Reactors Consist of ... 1 ) Reactor core: Fission takes place heat. 2) Steam Generator: heat from reactor core produces steam. 3) Turbine: steam spins the turbine to generate electricity. 4) Condenser: cools the steam back to liquid water.

33. Reactor core • Fission takes place here. • This area contains the fuel assemblies. • Each assembly has a control rod which absorbs neutrons. • By lowering and raising the control rod an operator can control the rate of the fission reaction.

34. Reactor core Lower the rod: less fission.Higher the rod: more fission.

35. Reactor core

36. Water Circuits Primary circuit: heats water to 293 °C (which is 560°F), using the energy from the fission reactor.High pressure keeps the water in liquid form.

37. Water Circuits Secondary circuit: boils water to steam and then converts back to liquid. Turbine is spun due to steam and change in pressure from cooling.

38. Water Circuits Tertiary circuit: provides cool water to the condenser (which cools the spent steam in the secondary circuit).As this water is heated, it is transferred from the condenser to the cooling tower (“lake").Once cool, the water is sent back to the condenser.

39. Secondary circuit Primary circuit Tertiary circuit

40. Nuclear Reactors in the US http://www.nei.org/doc.asp?catnum=2&catid=93 http://www.nukeworker.com/pictures/index.php?cat=10

41. Breeder Nuclear Fission

42. Safety& Nuclear Energy • Nuclear reactors contain huge steel structures called reactor vessels that will prevent the release of radiation leaks. • This vessel is placed in a containment building which is an additional precaution to prevent radiation leakage. (Earthquake, tornado, & "plane proof“ steel reinforced concrete walls 3-5 ft. thick.)

43. Chernobyl Before After http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/fschernobyl.html

44. Chernobyl • The Chernobyl accident in 1986 was the result of a flawed reactor design that was operated with inadequately trained personnel and without proper regard for safety. • The resulting steam explosion and fire released at least five percent of the radioactive reactor core into the atmosphere and downwind. • 28 people died within four months from radiation or thermal burns • 1999 Ukranian health minister reported the death toll was nearly 170,000 • 400,000 adults, 1 million children receiving govt aid for health • Inc in birth defects, infant leukemia, immune abnormalities • Preparing for an increase in adult cancers roughly 29 years later http://www.world-nuclear.org/info/chernobyl/inf07.htm

45. Chernobyl • On 25 April, prior to a routine shut-down, the reactor crew at Chernobyl-4 began preparing for a test to determine how long turbines would spin and supply power following a loss of main electrical power supply. Similar tests had already been carried out at Chernobyl and other plants, despite the fact that these reactors were known to be very unstable at low power settings. • A series of operator actions, including the disabling of automatic shutdown mechanisms, preceded the attempted test early on 26 April. As flow of coolant water diminished, power output increased. When the operator moved to shut down the reactor from its unstable condition arising from previous errors, a peculiarity of the design caused a dramatic power surge. • The fuel elements ruptured and the resultant explosive force of steam lifted off the cover plate of the reactor, releasing fission products to the atmosphere. A second explosion threw out fragments of burning fuel and graphite from the core and allowed air to rush in, causing the graphite moderator to burst into flames. • There is some dispute among experts about the character of this second explosion.  The graphite - there was over 1200 tones of it - burned for nine days, causing the main release of radioactivity into the environment http://www.world-nuclear.org/info/chernobyl/inf07.htm

46. Chernobyl • Some 5000 tones of boron, dolomite, sand, clay and lead were dropped on to the burning core by helicopter in an effort to extinguish the blaze and limit the release of radioactive particles. • Local lands decontaminated • Radioactive soil removed • Roads and buildings scrubbed

47. http://www.chernobyl-international.org/2020.html Chernobyl

48. Chernobyl

49. 3 Mile Island • Mar. 28, 1979 • 50% meltdown of the reactor core • no immediate deaths. • The cleanup cost more than $1.5 Billion. • Located 10 miles southeast of Harrisburg PA on the Susquahanna River. • The accident began in the early morning of March 28, when a little after 4:00 AM, pumps supplying water to TMI-2's steam generators tripped.  With no water, there would be no steam, and therefore the plant's safety system kicked into action and shut down the steam turbine and the generator it powered.  The nuclear reactions in the core continued until the system dropped the control rods into the core to halt the fission process, which is a process called "scramming."  Even with the control rods in the core, heat continued to rise because decaying radioactive materials left from the fission process continued to heat the water. The accidentaland radiation release, caused

50. 3 Mile Island • video http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.html