Physics 11 Nuclear Process. Nuclear Fusion Reactors Terminology Waste Storage Radiation and living things Nuclear Fission

Transcription

1 Physics 11 Nuclear Process Nuclear Fusion Reactors Terminology Waste Storage Radiation and living things Nuclear Fission

2 Nuclear Reactors Terminology Fission Control Rods, moderator, chain reaction half-life Fusion

3 Nuclear Fission Uranium splitting up 3 neutrons produced, each which can start another fission

4 Nuclear Fission during a nuclear fission reaction a large atom, typically uranium, splits in half the uranium atom is made unstable by adding an extra neutron once the uranium is unstable is will soon split (fission) in half the uranium splits into (typically) two half sized atoms and three neutrons

5 Nuclear Fission energy is also given off

6 Nuclear Fission E=mc 2 where does the energy come from? the products weigh less than the uranium that you started wit the missing mass is turned into energy anytime you split any atom bigger than Iron you get energy

7 Chain Reaction Nuclear Processes

8 Chain Reaction The large atoms are uranium The smallest blue dots are neutrons This reaction is growing

9 Chain Reaction super critical This reaction is growing or referred to as super critical A reaction that is staying the same size is critical A shrinking reaction is called sub critical

10 Control Rods absorb neutrons act like the brakes for a reaction keeps a reactor from going super critical once up to power if all the neutrons are absorbed no new reactions can begin the reactor shuts down

11 Moderator slows neutrons down so that they can be absorbed like the gas pedal for a reactor if neutrons are not slowed down they leave the core before starting another reaction in a CANDU reactor, the moderator is heavy water

12 Half Life the length of time it takes 1/2 of the atoms to decay for spent fuel the half life varies from 5 years to 5 million years means that the spent fuel stays radioactive for a long time

13 Half Life for example, Carbon 14 has a half life of approx years. If you start with 1000 grams, after 6000 years you have 500 grams After 12,000 years you have 250 grams After 18,000 years you have grams??

14 Nuclear Fission Reactor VERY SIMILAR TO COAL PLANT

15 Nuclear Fission Reactor VERY SIMILAR TO COAL PLANT Heat from reaction turns water into steam Steam causes turbine/generator to spin Source of heat is only difference

16 Nuclear Bombs a supercritical reaction very hard to imagine how powerful equivalent to millions of tons of TNT

17 Nuclear Bombs 1 stick of dynamite 2.1 MJ of energy given off enough to destroy a classroom/house

18 Nuclear Bombs Imagine a box, 1m by 1m by 1m this would be approx 1 ton of TNT enough to destroy a small town

19 Nuclear Bombs Hiroshima, August 6th 1945 equivalent to 20,000 tons of TNT if you placed the boxes next to each other would be 20 km long 12 mins to drive past at 100 km/hr Together in Hiroshima and Nagasaki, 210, 000 people died

20 Nuclear Bombs Modern Bombs measured in Megatons 1 mega ton = 1 million tons if you line up the boxes, 10 hours to drive past

21 Nuclear Bombs Modern Bombs USA 3 x 2 Megatons per missile USSR 1x 4 Megatons per missile

22 Nuclear Bombs 25 min documentary, dated, 1982, on nuclear weapons

23 Nuclear Bombs story from Wired.com re loss of control of nukes interesting incident similar to those mentioned in film

24 Nuclear Bombs