1. Nuclear Fuel Production Fissile Nuclei Uranium and Plutonium
239Pu

2. Uranium Two isotopes 99.3% 238U not useful for energy production
0.7% 235U useful for energy production
For a nuclear reactor: Need 4% 235U
For a fission bomb: Need 90% 235U

3. Reacting the Fuel: Fission Reactions

4. Chain Reactions

5. Controlling the Reactions: Control Rods

7. Producing Uranium Fuel
U ore contains small amounts of UO2 and UO3.
Step 1. Oxidize UO2 to UO3
Step 2. Solubilize U by reacting with H2SO4
UO3(s) + 2 H+(aq)  UO22+(solid salt) + H2O(l)
UO22+(solid salt) + 3 SO42-(aq)  UO2(SO4)34-(aq)
Key: Uranium is solubilized and is leached out of the rock.

8. Step 3. More Reactions, eventually to yield UO3
Step 3. More Reactions, eventually to yield UO3. 2R3N + H2SO4  (R3NH)2SO4 2 (R3NH)2SO4 + UO2(SO4)34-  (R3NH)4UO2(SO4)3 (aq) + 2SO42- (aq) (R3NH)4UO2(SO4)3 + 2(NH4)2SO4  4R3N + (NH4)4UO2(SO4)3 + 2H2SO4 2NH3 + 2UO2(SO4)34- (aq)  (NH4)2U2O7 (s) + 4SO42- (aq) (NH4)2U2O7 (s)  U3O8(s) + H2O(l) + NH3(g) U3O8 is then reacted to make pure UO3. Key: UO3 formed is pure.

9. Step 4. Formation of UF6
UO3(s) + H2(g) ====> UO2(s) + H2O UO2(s) + 4HF(g) ====> UF4(s) + 2H2O(l) UF4(s) + F2(g) ====> UF6(l or g) Key: UF6 has a boiling point near 50 oC.

10. Step 5. Fuel-Level Enrichment: 4%

11. Efficiencies:
Diffusion method = 1.002/stage
Final Fraction = 0.70 x (1.002)#cycles
Calculate # cycles to make 4.0% 235U
Calculate # cycles to make 90.0% 235U

12. Efficiencies:
Centrifuge method = 1.2/stage
Final Fraction = 0.70 x (1.2)#cycles
Calculate # cycles to make 4.0% 235U
Calculate # cycles to make 90.0% 235U

13. Made inside Uranium Nuclear Reactors
Plutonium Fuel:
Made inside Uranium Nuclear Reactors
Fast neutron reactors
(Also called fast breeder reactors)

14. 235U

15. Artificial Transmutations

16. Creation of Transuranium Elements

22. Radioactive Dating First-order Reaction
First-order Reaction

23. Specifics for Dating of Earth and Previously Living Things
Units of Radioactivity:
Curie, Ci = 3.7 x 1010 disintegrations/sec
Becquerel, Bq = 1 disintegration/sec
C N years