NUCLEAR FISSION

Fission

Splitting the Nucleus

Caused by: neutron hitting

nucleus

Most cases split in 2 main

parts (binary fission)

Releases Energy

Products Some Possible Products: Ba, Kr, Sr, Cs, I and Xe

Some Possible Reactions:

235U + 1 neutron  → 92Kr + 141Ba + 3 neutrons + ENERGY

235U + 1 neutron →  94Sr + 140Xe + 2 neutrons + ENERGY

Probabilities

Products have certain probabilities

Mass ratio of products generally around 3:2

E=mc2 Mass of products is 0.1% LESS than

mass of reactants

E = m c 2

Each reaction releases around 200 MeV (3.204353×10-11 Joules)

Energy ProducedIn Joules

Change in massIn kilograms

Speed of Light Squared90,000,000,000,000,000 meters/second

Chain Reaction

Self-sustaining

Each reaction produces more neutrons

Every neutron doesn’t hit another nucleus

Need a critical mass

Applications

Nuclear BombsUncontrolled chain reactionRelease energy at once

Nuclear EnergyControlled chain reactionRelease energy slowly

Nuclear Bomb Two types of fission

bombs First test released

same energy as 20,000 tons of TNT

Aug. 6 and 9, 1945 detonated over Hiroshima and Nagasaki killing 200,000 People

Nuclear Power

20% of U.S. Energy from Nuclear

10 million times the energy per reaction compared to burning coal

Radioactive Waste

Nuclear Reactor

Operation Mousetrap

Example of chain reaction! To think about:

How is it similar and different from nuclear fission?

http://www.youtube.com/watch?v=noSSDMjcchI

Sources Slide 2: http://en.wikipedia.org/wiki/File:Stdef2.png Slide 3: http://www.atomicarchive.com/Fission/Fission1.shtml Slide 4: http://world-nuclear.org/education/phys.htm Slide 6: http://en.wikipedia.org/wiki/File:Fission_chain_reaction.svg Slide 7: http://en.wikipedia.org/wiki/File:Nagasakibomb.jpg

http://insp.pnnl.gov/-reports-pocketbook-czechrep.htm Slide 8:

http://en.wikipedia.org/wiki/File:Fission_bomb_assembly_methods.svg

Slide 9: http://en.wikipedia.org/wiki/File:2008_US_electricity_generation_by_source_v2.png

Slide 10: http://www.cameco.com/uranium_101/uranium_science/nucl

ear_reactors/