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Nuclear Power: Advanced Generations and Outlook. david Van Wagener November 26, 2008 CHE 384: technology report. Why do we like nuclear power?. Nuclear power production has “zero emissions” 97% of waste is low/intermediate level
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Nuclear Power: Advanced Generations and Outlook david Van Wagener November 26, 2008 CHE 384: technology report
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 • Enuclear = 1e8 * Echemical • 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% 235U), moderated with graphite • Generation II • Includes reactor designs most widely found today • Produced through 1990s • Mostly run on enriched uranium (3-4% 235U), 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 H2 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
References • DOE. (2003, January). DOE Fundamentals Handbook: Nuclear Physics and Reactor Theory. Retrieved November 9, 2008, from http://www.hss.energy.gov/NuclearSafety/techstds/standard/hdbk1019/h1019v2.pdf • DOE. (n.d.). What Is Generation IV? Retrieved November 10, 2008, from U. S. Department of Energy: http://www.ne.doe.gov/GenIV/neGenIV1.html • Gen IV International Forum. (n.d.). GEN-4: Technology: Systems. Retrieved November 7, 2008, from http://www.gen-4.org/Technology/systems/vhtr.htm • Hore-Lacy, I. (2008, March 3). Nuclear Power Reactor. Retrieved November 9, 2008, from Encyclopedia of Earth: http://www.eoearth.org/article/Nuclear_power_reactor • Laboratoire de Physique. (2001, November). Molten Salt Reactors Based on the Th-U3 Fuel Cycle. Retrieved November 11, 2008, from http://lpsc.in2p3.fr/gpr/english/MSR/MSR.html • Tester, J. W., Drake, E. M., Driscoll, M. J., Golay, M. W., & Peters, W. A. (2005). Sustainable Energy. Boston: MIT Press. • Westinghouse. (n.d.). PWR Cycle. Retrieved November 9, 2008, from Nuclear Tourist: http://www.nucleartourist.com/type/pwr_cycle.htm • WNA. (2006, June). Radioactive Wastes-Myths and Realities. Retrieved November 9, 2008, from World Nuclear Association: http://www.world-nuclear.org/info/inf103.html • World Nuclear Association. (2008, June). Supply of Uranium: WNA. Retrieved November 7, 2008, from http://www.world-nuclear.org/info/inf75.html