1. Nuclear Power
Arjun M., Clay B., Vincent Z.,Taylor J., Ashish M., Paul D., Geneva S., Jacalyn P.

2. What is Nuclear Energy?
“The energy released during nuclear fission or fusion, especially when used to generate electricity.”

3. The Atom Proton: Positively charged; in the nucleus
Neutron: Neutrally charged; in the nucleus
Electron: Negatively charged; in orbitals around the nucleus

4. Fission vs. Fusion
Fission: “a nuclear reaction in which a heavy nucleus splits spontaneously or on impact with another particle, with the release of energy”
This is the type of reaction that is harnessed in nuclear reactors today
Requires heavy atomic nucleus, such as uranium or plutonium
Fusion: “a nuclear reaction in which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy.”
Fusion is the process that occurs within the sun. It has the higher energy potential but it is not yet used on earth because of the need for high temperatures

5. Description Of Process
Nuclear energy originates from the splitting of uranium atoms – a process called fission. This generates heat to produce steam, which is used by a turbine generator to generate electricity.

6. How does Fission Work?

7. Fission
Process can occur spontaneously or can be induced by excitation of particles within the atom or through electromagnetic radiation
Energy is released and neutrons are emitted, which can then spark fission reactions in nearby atoms, releasing even more energy
This is known as a chain reaction

8. Process of Nuclear Reaction

9. Pressurized Water Reactor (PWR)
Common type of thermal reactor
Goal of the PWR is to take the energy released from fission to create high-pressure steam that can turn a turbine and power an electrical generator
Process is a little harder than for fossil fuels
PWR transfers energy from moderator and fuel rods using closed water system under pressure
Advanced Gas-cooled Reactors (AGR) reactors in UK use CO2 instead of water

10. Uranium 2 main isotopes: U-235 and U-238
U-235: fissile and the one used in the nuclear fission process. Very rare (1% of all uranium)
U-238: Main isotope (99% of all uranium) and not fissile. Still used as a neutron absorber
4 steps in bringing uranium from raw element to usable fuel for nuclear processes
Mining and milling
Mining is done in Kazakhstan, Canada, Australia, Niger, Namibia, Russia, and West US
Conversion
Enrichment
Add U-235 to a uranium fuel until it is around 3% U-235
Fuel fabrication
Converted from powder to pellets

11. Thermal Neutrons
Most of the energy released in fission takes the form of kinetic energy of the fission fragments and neutrons emitted in the process
These neutrons are moving extremely fast (around km/s)
Too fast to be effective in causing further fissions
To be effective in facilitating chain reaction, speed of the electrons should be around 2 km/s
This is the speed that neutrons have when in equilibrium at room temperature
These neutrons are called thermal neutrons

12. Moderators
Slower neutron speeds are necessary for further fissions and to help transfer energy to later stages
To remove some of this excess kinetic energy, the power plant will use a moderator, which is something that moderates (slows down) the speeds of the neutrons
The high speed neutrons collide with moderator atoms inelastically and slow down
This process is done again and again until the neutron become thermal neutrons
Good moderators do not absorb neutrons and are inert in the reactor
Common moderators in reactors are water and graphite

13. Control Rods
Power plants need to regular power output and be able to shut down operation if needed
Control rods can be lowered into the reactor to attract neutrons
With less neutrons available for reaction, rate of reaction decreases
Control rods are usually made of boron or other elements that absorb neutrons well

14. Heat Exchanger Last part of nuclear power station
Conveys internal energy from reactor to the turbines
Closed-system that transfers energy from the hot regions of the reactor to the turbine
Heat exchanger is necessary because if the energy was transferred directly from the moderator to the turbine there would be risk of radioactive material making it out of the reactor
With closed-system of heat exchanger, this can be avoided

15. Pros and Cons of Source Pros Cons Low Pollution Low Operating Costs
Reliability
More Proficient Than Fossil Fuels
Cons
Environmental Impact
Radioactive Waste Disposal
Nuclear Accidents
Uranium is Finite

16. Low pollution and low production costs
Nuclear energy is actually quite eco-friendly, despite having the word ‘nuclear’ in the name. There are a only a few obvious by-products of nuclear energy generation, the most prevalent of which is steam, which is not at all a pollutant.
Nuclear energy has low production costs, because you basically just let the uranium sit there while it undergoes fission, which is not especially difficult to induce. It is also reliable, because uranium atoms undergoing fission will always continue to undergo fission until they run out, because that’s how physics works.

17. Some bad things about nuclear energy generation
Nuclear power plants produce nuclear waste, most oftenly in the form of cobalt- 60, cesium-137 and iridium-192. These isotopes are especially radioactive, and must be disposed of properly. If not handled carefully, these substances can erode the land around them and harm local ecosystems.

18. Safety Issues
Thick steel and concrete around the walls of the reactor vessel as well as the reactor itself to shield the outside from alpha particles, beta particles, and gamma rays
The reactor can get very hot and the water is essential to keeping the reactor cool: emergency measures need to be in place in case of a reactor accident so that the reactor does not go into meltdown
The fuel rods become radioactive after use so humans should be handle or be near them in general

19. Specific Energy of Uranium 235
When on uranium 235 nucleus undergoes fission, 3.2*10^-11 joules of energy is released.
The mass of a uranium 235 atom is 4.0*10^-25 kg.
Therefore, the specific energy of uranium 245 is...
8.0*10^13 J/kg

20. Energy Density of Uranium 235
1 kg of uranium 235 is 5*10^-5 cubic meters
Thus, by taking the specific energy of uranium 235 and dividing it by its volume, the energy density of uranium 235 can be found:
1.6*10^18 J/m^3

21. Types of Reactors Pressurized Water Reactors (PWR)
Boiling Water Reactors (BWR)
Fast-neutron reactor
Advanced Gas-cooled reactor
Breeder Reactor

22. Country most commonly found or used
72.3% of France’s energy is from nuclear power
20% more than second place, Slovakia
Top 10 countries are all in Europe

24. Approximate Efficiency of this source
Nuclear Power is one of the most efficient sources of energy, coming in at an respectable 33-37%
The capacity of nuclear power is at an astounding 91%, which is the ratio between the amount of energy a plant could be producing at peak optimization and what it actually produces.

25. “Fun” facts!
Nuclear energy is being used in more than 30 countries around the world and even powers Mars rovers.
Nuclear energy comes from uranium, a nonrenewable resource that must be mined.
Nuclear power plants generate about 20% of U.S. electricity.
Nuclear energy accounts for two-thirds of all carbon-free electricity.
Nuclear plants are the lowest-cost provider of large-scale electricity.
Some states generate more than half of their electricity from nuclear power.
One uranium fuel pellet makes as much energy as one ton of coal, 149 gallons of oil, and 17,000 cubic feet of natural gas

26. Works Cited!!!
“How a Nuclear Reactor Works.” Nuclear Energy Institute, NEI,
Fetter, Steve. “How Long Will the World's Uranium Supplies Last?” Scientific American, Scientific American, Mar. 2009,
“GCSE Bitesize: Nuclear Power.” BBC, BBC,
“Nuclear Power in the World Today.” World Nuclear Association,
“Nuclear Power Plant.” Nuclear Power Plant, Energy Education, energyeducation.ca/encyclopedia/Nuclear_power_plant.