1. 19.5 NUCLEAR POWER ZACH ANDERSON ADAM CORE CH.19 CONVENTIONAL ENERGY

2. NUCLEAR POWER Beginning in the early 1950’s, President Eisenhower wanted to move towards a more nuclear-powered society. He presented “Atoms for Peace” speech before the United Nations in 1953, pushing for nuclear-powered generators to provide clean, abundant energy. He pushed for nuclear energy as an alternative resource because it would fill the deficit that came from shortages of oil and natural gas. This was also a very cheap form of energy. Between 1970-1974 American utilities ordered 140 new reactors for power plants. However in recent decades, increasing construction costs, declining demand for electric power and safety issues have made nuclear energy far less favorable.

3. NUCLEAR REACTORS The most commonly used fuel in nuclear power plants is U ₂₃₅, which is a naturally occurring radioactive isotope of uranium. Usually U ₂₃₅ makes up less than 1% of uranium ore. Many people who are exposed to uranium mines suffer from lung cancer due to high levels of radon and dust.

5. NUCLEAR REACTORS (CONTINUED) U ₂₃₅ concentrations must reach 3%, so it can be formed into cylindrical pellets. 100 rods together make up a fuel assembly. These fuel assemblies are packed together in a heavy steel vessel. The radioactive uranium particles produced are unstable and undergo nuclear fission, releasing energy and neutrons.

6. FISSION PROCESS

7. REACTOR DESIGNS 70% of the nuclear plants in the world are pressurized water reactors, (PWR) where water circulates through the core and absorb heat as it cools the fuel rods. There is a simpler, but dirtier and more dangerous reactor is the boiling water reactor (BWR). In this model, water from the reactor core boils to make steam, which directly drives the turbine-generators.

8. REACTOR USES Britain, France, and the former Soviet Union all use a common reactor design that uses graphite, both as a moderator and as the structural material for the reactor core. Britain uses MAGNOX, while in the Soviet the RBMK was used. These were all originally thought to be safe due to graphite’s high capacity for both capturing neutrons and dissipating heat. One of the most well known disasters was at Chernobyl, caused from burning graphite.

9. ALTERNATIVE DESIGNS HTGCR- High Temperature Gas-Cooled Reactor PIUS- Process-Inherent Ultimate Safety reactor

10. HTGCR Fuel pellets are encased in ceramic. Helium is used as the coolant. All Coolant can be lost and no meltdown will occur. Examples: Brown’s Ferry Reactor in AL (failed) General Atomic in Europe (successful) Suffered complete coolant loss—survived.

11. PIUS

12. BREEDER REACTORS Special reactors that create fuel from U 238.

13. BREEDER REACTORS Advantages Create enough fuel to power nuclear plants for 100+ years Use an abundant form of uranium Disadvantages Has to be run at high temperature so water can’t be used as coolant. Liquid Na is used. Produce weapons grade plutonium.