Alternative FuelsMichael Fink, Steve Haidet,
& Mohamad Mohamad
Thorium
Molten Salt Reactor
Energy Generation Comparison
6 kg of thorium metal in a liquid-fluoride reactor has the energy equivalent (66,000
MW*hr electrical*) of:
=
230 train cars (25,000 MT) of bituminous coal or,
600 train cars (66,000 MT) of brown coal,
(Source: World Coal Institute)
or, 440 million cubic feet of natural gas (15% of a 125,000 cubic meter LNG tanker),
or, 300 kg of enriched (3%) uranium in a pressurized water reactor.
*Each ounce of thorium can therefore produce $14,000-24,000 of electricity (at $0.04-0.07/kW*hr)
Energy Extraction Comparison
Uranium-fueled light-water reactor: 35 GW*hr/MT of natural uranium
1000 MW*yr of electricity
33% conversion efficiency (typical
steam turbine)
3000 MW*yr of thermal energy
32,000 MW*days/tonne of heavy metal (typical
LWR fuel burnup)
39 MT of enriched (3.2%) UO2 (35 MT U)
Conversion and fabrication
365 MT of natural UF6 (247 MT U)
293 MT of natural U3O8
(248 MT U)
Thorium-fueled liquid-fluoride reactor: 11,000 GW*hr/MT of natural thorium
Conversion to UF6
1000 MW*yr of electricity
50% conversion efficiency (triple-
reheat closed-cycle helium gas-turbine)
2000 MW*yr of thermal
energy
914,000 MW*days/MT 233U (complete burnup)
0.8 MT of 233Pa formed in reactor blanket from
thorium (decays to 233U)
Thorium metal added to blanket salt through
exchange with protactinium
0.8 MT of thorium metal
0.9 MT of natural ThO2
Conversion to metal
Uranium fuel cycle calculations done using WISE nuclear fuel material calculator: http://www.wise-uranium.org/nfcm.html
Waste generation from 1000 MW*yr uranium-fueled light-water reactor
Mining 800,000 MT of ore containing 0.2% uranium (260 MT U)
Uranium fuel cycle calculations done using WISE nuclear fuel material calculator: http://www.wise-uranium.org/nfcm.html
Generates ~600,000 MT of waste rock
Conversion to natural UF6 (247 MT U)
Generates 170 MT of solid waste and 1600 m3 of liquid waste
Milling and processing to yellowcake—natural U3O8
(248 MT U)
Generates 130,000 MT of mill tailings
Enrichment of 52 MT of (3.2%) UF6 (35 MT U)
Generates 314 MT of depleted uranium hexafluoride (DU); consumes 300 GW*hr of electricity
Fabrication of 39 MT of enriched (3.2%) UO2 (35 MT U)
Generates 17 m3 of solid waste and 310 m3 of liquid waste
Irradiation and disposal of 39 MT of spent fuel
consisting of unburned uranium, transuranics, and fission products.
Waste generation from 1000 MW*yr thorium-fueled liquid-fluoride reactor
Mining 200 MT of ore containing 0.5%
thorium (1 MT Th)
Thorium mining calculation based on date from ORNL/TM-6474: Environmental Assessment of Alternate FBR Fuels: Thorium
Generates ~199 MT of waste rock
Milling and processing to thorium nitrate ThNO3 (1 MT Th)
Generates 0.1 MT of mill tailings and 50 kg of aqueous wastes
Conversion to metal and introduction into reactor blanket Breeding to U233 and
complete fission
Disposal of 0.8 MT of spent fuel consisting
only of fission product fluorides
…or put another way…
Mining waste generation comparison
Mining 800,000 MT of ore containing 0.2% uranium (260 MT U)
Uranium fuel cycle calculations done using WISE nuclear fuel material calculator: http://www.wise-uranium.org/nfcm.html
Generates ~600,000 MT of waste rock
Conversion to natural UF6 (247 MT U)
Generates 170 MT of solid waste and 1600 m3 of liquid waste
Milling and processing to yellowcake—natural U3O8
(248 MT U)
Generates 130,000 MT of mill tailings
Mining 200 MT of ore containing 0.5%
thorium (1 MT Th)
Generates ~199 MT of waste rock
Milling and processing to thorium nitrate ThNO3 (1 MT Th)
Generates 0.1 MT of mill tailings and 50 kg of aqueous wastes
1 GW*yr of electricity from a uranium-fueled light-water reactor
1 GW*yr of electricity from a thorium-fueled liquid-fluoride reactor
Operation waste generation comparison
Uranium fuel cycle calculations done using WISE nuclear fuel material calculator: http://www.wise-uranium.org/nfcm.html
1 GW*yr of electricity from a uranium-fueled light-water reactor
1 GW*yr of electricity from a thorium-fueled liquid-fluoride reactor
Enrichment of 52 MT of (3.2%) UF6 (35 MT U)
Generates 314 MT of DUF6; consumes 300 GW*hr of electricity
Fabrication of 39 MT of enriched (3.2%) UO2 (35 MT U)
Generates 17 m3 of solid waste and 310 m3 of liquid waste
Irradiation and disposal of 39 MT of spent fuel consisting of
unburned uranium, transuranics, and fission products.
Conversion to metal and introduction into reactor blanket Breeding to U233 and
complete fission
Disposal of 0.8 MT of spent fuel consisting
only of fission product fluorides
Abundant?
Negatives
¨ Risk of accidents¨ Highly radioactive nuclear waste
Future?
Ammonia, Natural Gas
Household Alternative Fuels
Ammonia Fuel?
¨ NH3¨ Common uses:
cleaning supplies, fertilizer, explosives
¨ Ammonia: 21.36 BTU/g
¨ Oil: 45.97 BTU/g,¨ Requires minor
modifications to carburetors/injectors
Sources
¨ Atmospheric nitrogen and free hydrogen
¨ Haber–Bosch process
¨ Electrolysis¨ Coal gasification
http://en.wikipedia.org/wiki/File:Production_of_ammonia.svg
Haber–Bosch process
¨ CH4 + H2O → CO + 3 H2¨ N2 (g) + 3 H2 (g) 2 NH3 (g)⇌¨ It is estimated that half of the protein within
human beings is made of nitrogen that was originally fixed by this process
http://en.wikipedia.org/wiki/File:Haber-Bosch-En.svg
Natural Gas fuel?
¨ Methane: 53.88 BTU/g¨ used in over 12 million
vehicles¨ reliable and safe¨ Fuel storage occupies a
large amount of space
http://upload.wikimedia.org/wikipedia/commons/e/e0/Carroagas.jpg
Domestic Natural gas supplies
http://www.roperld.com/science/minerals/FossilFuels.htm#USGas
World Natural gas supplies
http://www.roperld.com/science/minerals/FossilFuels.htm#WorldGas
World Natural Gas Supplies Including Shale Gas
http://www.roperld.com/science/minerals/FossilFuels.htm#WorldGas
Conclusions
¨ Ammonia would function as a fuel, but why not use natural gas
¨ only sustainable for several decades with optimistic supplies
¨ reduced environmental impact
¨ partially existing infrastructure
http://www.eia.gov/pub/oil_gas/natural_gas/analysis_publications/ngpipeline/ngpipelines_map.html
Plasma Arc Waste Disposal
Turning Everyday Garbage into Everyday Energy
The Technology
¨ Garbage is passed through a plasma arc, which reaches 10,000 deg F, instantly vaporizing it.
¨ Organic material turns into syngas, which can be used to drive electrical turbines.
¨ Inorganic material turn into slag.
Renewability
¨ America produces about 675,000 tons of garbage a day.
¨ 1500 tons of trash = 60 MW
¨ Almost all of the trash is converted into usable byproducts, eliminating landfills.
Pros
¨ After initial energy is spent to ignite the plasma arc, the process is self-sustaining.
¨ Electricity prices will be able to compete with natural gas.
¨ Ability to turn medical and hazardous waste inert.
¨ Material made from non-organic waste can be sold commercially.
Cons
¨ Dumping garbage at a plasma arc facility costs $137 more per ton.
¨ Some CO2 produced.
¨ Performance based on the content and consistency of the waste.
¨ Current plant designs are less than 50% efficient at best.
¨ Expensive liners need replaced every year
¨ Unproven in a large-scale setting
Questions?