1. Fission and Fusion

2. Fission is the splitting of a heavy atom into
Two or more lighter nuclei
Fusion is combining two small nuclei to make a heavier nucleus

3. Fission and Fusion break the Law of Conservation of Mass!!!
The law says mass (matter) can not be created or destroyed.
However, in these nuclear reactions, a bit of mass IS destroyed, and converted into….

4. LOTS OF ENERGY!

5. How much energy?
Einstein says…..

6. Einstein’s equation

7. Energy = mass x (speed of light)2
Energy = mass x (speed of light)
X very very big
Very big =
Very small

8. In fusion and fission, small amounts of mass are converted into huge amounts of energy
Compared to a gram of natural gas (methane), a gram of material converted to energy in a nuclear reaction gives off one BILLION times more energy

9. Fission Reactions Neutron + U-235 A neutron is fired at U-235
and is captured, forming unstable U-236, which then splits up

10. Fission Reactions n + U Ba + Kr + 3 n + energy1
235
142 91 1
n U Ba Kr n + energy 92 56 36
A neutron bombards a U-235 and it splits into Ba-142, Kr-91
three neutrons and ENERGY
The three neutrons can then go on to start other fission
reactions

11. This can be the start of a chain reaction

12. Nuclear power plants use fission to create energy to make electricity
Three Mile Island

13. Nuclear Reactors FUEL CONTROL Must be FISSIONABLE
Controlled chain reactions
U-233
U-235
Pu-239
Radioactive Waste can be solid, liquid or gas
Control Rods (MODERATORS) absorb neutrons
Control rods made of Cadmium (Cd), Graphite (C), Boron (B)
COOLANT = Liquid Sodium Na (l) or Heavy Water
Steel and High Density concrete shield personnel

14. Nuclear Reactor

15. Nuclear accidents can happen when the chain reaction goes out of control

16. Thanks to FUSION, we have sunlight!
Hydrogen fuses with
Hydrogen to make
Helium + energy
in stars, like
our own sun

17. Fusion Fusion is not as dangerous as fission Unfortunately ……
it can not yet be used in power plants because too much energy is needed to overcome the repulsion of the two positively charged nuclei to be cost effective