1. Objectives
To introduce fusion and fission as sources of energy
To learn about nuclear fission
To understand how a nuclear reactor works
To learn about nuclear fusion
To understand nuclear weapons
To see how radiation damages human tissue

2. Two types of nuclear processes can produce energy
A. Nuclear Energy
Two types of nuclear processes can produce energy
Combining 2 light nuclei to form a heavier nucleus - fusion
Splitting a heavy nucleus into 2 nuclei with smaller mass numbers - fission
Energy produced by conversion of mass, E = mc2
Sun converts 4 million tonnes per second
Fusion and Fission POGIL

3. B. Nuclear Fission
Each atomic fission produces 3 neutrons
Releases 2.1 1013 J/mol uranium-235
(Burning methane produces 8.90 x 105 J/mol)

4. B. Nuclear Fission
Chain reaction – self sustaining fission process caused by the production of neutrons that proceed to split other nuclei Chain Reaction Alternative CR
Critical mass – mass of fissionable material required to produce a chain reaction

5. C. Nuclear Reactors

6. C. Nuclear Reactors
Reactor core
Nuclear Power Plants

7. B. Nuclear Fission Chernobyl 1 Chernobyl 2 Chernobyl 3
Nuclear Energy in the US?

8. D. Nuclear Fusion
Process of combining two light nuclei
Produces more energy per mole than fusion
Powers the stars and sun

9. D. Nuclear Fusion
Atoms lighter than Fe. Deuterium used
Requires extremely high temperatures ~ 1 billion K
Currently not technically possible for use as a power source – issues with confinement
Used as “Hydrogen bomb”
Sun’s energy captured for our use

10. Nuclear Binding Energy

11. Nuclear Weapons
Fission Weapons (“Atomic Bombs”)
Enriched uranium or plutonium
Supercritical mass produced in bomb
Limited up to 500 kilotons of TNT
Twice used in warfare (Hiroshima and Nagasaki)

12. Nuclear Weapons
Fusion Weapons (“Thermonuclear / Hydrogen Bombs”)
deuterium and tritium
fission bomb compresses and heats hydrogen fuel
further stages of fission reactions (depleted uranium)
largest so far is 57 megatons (“Tsar Bomba” - USSR)
Radioactive fallout can be regulated – salted, neutron bomb

13. Missiles (land or submarine launch)
Nuclear Weapons
Delivery
Gravity bombs
Missiles (land or submarine launch)
Multiple Independent Re-entry Vehicles
“Tactical” weapons: shells, torpedoes
“Now I am become Death, the destroyer of worlds”
Strategy
“Cold War, Arms Race”
“Mutually Assured Destruction”
Missile Defense
Terrorist Threat
WWII

14. Regulation
UN, International Atomic Energy Agency
Test Ban and Nuclear Non-Proliferation Treaties
SALT’s and START’s (limitation and reduction)
Still enough to destroy most human life on Earth (23,000 bombs equivalent to 150,000 Hiroshima bombs)
US, Russia, China, UK, France, India, Pakistan, North Korea, Israel (?), South Africa (X)
Obama (“World without nuclear weapons”)
Nuclear Weapons

15. Factors Determining Biological Effects of Radiation
E. Effects of Radiation
Factors Determining Biological Effects of Radiation
Energy of the radiation
Penetrating ability of the radiation
Ionizing ability of the radiation
Cell repair, death (high dose / acute damage), incorrect repair (low dose / cancer)
Chemical properties of the radiation source
Strontium-90 and Radium-226 behave similarly to calcium so tend to accumulate in bones. Radioactive Iodine concentrates in the thyroid

16. Penetrating Ability of Radiation
Alpha radiation consists of helium nuclei and is readily stopped by a sheet of paper. Beta radiation, consisting of electrons or positrons, is halted by an aluminum plate. Gamma radiation is dampened by lead

17. E. Effects of Radiation
Rem: the quantity of ionizing radiation whose biological effect is equal to that produced by one roentgen of x-rays. Roentgen is a defined amount of ionization of dry air

18. U.S.Nuclear Regulatory Commission limit of 5,000 mrem/year above background for nuclear industry workers