DAVID VAN WAGENER NOVEMBER 26, 2008 CHE 384: TECHNOLOGY REPORT Nuclear Power: Advanced Generations and Outlook

Why do we like nuclear power? Nuclear power production has “zero emissions”  97% of waste is low/intermediate level Safer designs are being engineered, making a “Chernobyl” far less likely Nuclear power boasts greater efficiency than older technologies

Nuclear Power Basics Sustained nuclear fission of heavy elements releases energy  Fission is controlled by using neutron poisons and moderators E nuclear = 1e8 * E chemical Annual fuel for 1000 MW plant  3 million tons of coal  36 tons of enriched uranium Thermal energy from fission creates steam for power production

Generations of Nuclear Technology Generation I  Prototype technology, very few still operational  First reactor designs developed in 1950s and 1960s  Run on natural uranium (0.7% 235 U), moderated with graphite Generation II  Includes reactor designs most widely found today  Produced through 1990s  Mostly run on enriched uranium (3-4% 235 U), water moderated  Design types include:  Boiling water reactor  Pressurized water reactor

New Generation Technology Generation III  Implements enhanced safety features compared to Generation II  These “advanced reactors” and began utilizing:  Standard designs between all models  Improved models with extended operating lives (≈60 years)  Higher burn up, reducing fuel use and waste  “Passive safety mechanisms”  Natural resistance to high temperatures  Design types include:  Light water reactors (advanced BWR’s, advanced PWR’ s)  Heavy water reactors (CANDU)

Future Technologies Generation III+  More advanced safety features  Plans have been adopted, operational plants by 2010 Generation IV  Heavily researched, but only theoretical (so far)  Advanced designs use new coolants like supercritical water, helium, and molten salt  Like previous generation advancements, the primary focus is:  Improved safety mechanisms  Decreased cost of construction and operation

Pebble Bed Reactors Very high-temperature gas cooled reactor Helium cools fuel pebbles and transfers thermal energy to turbines  Helium does not carry radioactivity “Pebble” fuel contains uranium oxycarbide fuel coated in carbon layers, surrounded by graphite and encased in silicon carbide Generates heat up to 1000°C, ideal for applications like S-I cycle for H 2 production

A Future for Nuclear Energy? Approximate uranium resources = 5500 kt Annual usage = 65 kt  15% of global demand, 20% of US demand Uranium reserves will run out in:  84 years at current usage rate  42 years if nuclear power becomes 100% of US energy  13 years if nuclear power becomes 100% of global energy Thorium has larger reserves and is proposed as alternate fuel Breeder reactors are considered a solution, but their safety is scrutinized

Conclusions Evolving nuclear technology is developing safer and more efficient plants Future generation technology could help support a hydrogen economy “The End of Uranium” could be a heavy factor determining the upcoming role of uranium in energy production Chernobyl and Three Mile Island still make people wary to fully welcome nuclear power

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