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Beginning in the early 1950s, President Eisenhower's "Atoms for Peace" initiative advocated for nuclear power as a clean and abundant alternative to fossil fuels. The push led to a surge in reactor orders, but recent decades have seen a decline in nuclear energy's favorability due to rising construction costs, safety concerns, and reduced electricity demand. This overview delves into nuclear fuel, reactor designs, including Pressurized Water Reactors and High-Temperature Gas-Cooled Reactors, and addresses the advantages and disadvantages of breeder reactors, highlighting the balance between energy needs and safety.
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Ch.19 Conventional Energy 19.5 Nuclear Power Zach Anderson Adam Core
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.
Nuclear Reactors • The most commonly used fuel in nuclear power plants is U₂₃₅, which is a naturally occurring radioactive isotope of uranium. • Usually U₂₃₅ 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.
Nuclear Reactors (continued) • U₂₃₅ 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.
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.
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.
Alternative Designs • HTGCR- High Temperature Gas-Cooled Reactor • PIUS- Process-Inherent Ultimate Safety reactor
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.
Breeder Reactors • Special reactors that create fuel from U238.
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.
