GLG110 Geologic Disasters

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GLG110 Geologic Disasters the Environment
Today Chapter 13 Alternate Energy Resources
TA Carol Butler Email clbutler_at_asu.edu
Instructor Professor Stanley Williams Email
stan.williams_at_asu.edu
Course Website http//glg110.asu.edu
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Disaster of the Day -AZ Gas Crisis

• How many of you rushed out to get gas when you
  learned about the situation?
• WHY?

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AZ Gas Crisis

• Rupture occurred on July 30
• Gas Crisis happened in mid-August
• Same amount of gas was available in Tucson only
  some delays trucking it to Phoenix
• Media fueled public anxieties
• People rushed to get gas even if they were not
  low demand skyrocketed
• Supply could not meet demand panic induced
  shortage

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AZ Pipeline Discussion

• State government and industry concerns over the
  crisis fueled new discussions about how to
  prevent such a situation in the future
• One option build a new refinery in Arizona

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AZ Refinery?

• Refinery proposed in Mobile (or possibly near
  Yuma)
• Arizona Clean Fuels company
• Long considered new interest due to crisis
• Primarily African-American community
• This community already is burdened with gt45 of
  Arizonas landfill capacity
• Create new jobs?

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AZ Refinery Issues

• Dept. of Environmental Quality Arizona permit
  issues for refinery air environmental quality
• Next to elementary school and residential homes
• Company would have to either buy or build new
  school depending on community preference

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AZ Refinery Issues

• If built there is still pipeline issue (this one
  would be from Mexico)
• No new refineries have been built in recent years
• Supply demand balanced?
• Do we need a new one?

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AZ Refinery Issues

• Solvents (benzine) put out in large quantities
  from refineries
• Phoenix basin trapping?
• AZ not have strong state law on airborne
  pollutants
• Buffer zone required (1 mile for moderate
  impact)
• Air modeling shows further from refinery less
  effect from emissions, dissipate in air, wind
  patterns important

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AZ Refinery Issues

• Cost benefits of environmental protection
• Fewer illness
• Fewer clean-up costs
• Operate more efficiently
• Fewer waste disposal costs due to recycling

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Alternate Energy Resources

• Nonrenewable
• Nuclear
• Geothermal
• Methane Hydrate
• Renewable
• Solar
• Hydrogen
• Water Power
• Wind
• Biomass

All the renewable resources are driven by solar
energy
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Nuclear Energy

• Currently supplies 20 U.S. electricity Some
  countries around world are much more dependent on
  nuclear energy

• Energy from nuclear fission
• Problems
• Accidents
• Waste Disposal
• Non-renewable

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Nuclear Energy

• Uses uranium
• Originates in magma so found in granitic but more
  often in sedimentary rocks
• Bombard with neutrons to split atoms
• Produces more neutrons and heat
• Creates chain reaction
• Controlled within reactor

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Nuclear Energy

• Not long-term sustainable at current rates of
  uranium consumption
• Current reactors only use 1 of the uranium put
  in the rest waste
• Breeder reactors turn that waste into plutonium
• Could theoretically supply 1/2 energy currently
  produced by fossil fuels for 2000 years
• Technology must be enhanced for this to be
  possible

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Risk/Benefit Analysis

• Hot Debate
• Radiation released at every stage
• Serious hazards with mining, processing,
  transporting, using, and storing, both nuclear
  energy and waste
• Weapon potential
• Meltdown accident where nuclear fuel becomes so
  hot it becomes molten mass
• Containment fails
• Pollution occurs

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Three Mile Island

• March 1979, Harrisburg, PA
• Malfunction of a valve and human error resulted
  in partial meltdown which released small amount
  of radioisotopes into environment
• Containment structure functioned as designed and
  prevented massive radiation leak
• Lack of preparedness in community
• Long-term effects poorly understood

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Chernobyl

• April 1986, Soviet Union - Worst nuclear disaster
  in human history
• First detected in Sweden, thought high radiation
  levels coming from their plant
• When confronted Soviets admitted accident
  happened two days earlier
• Human error relating to cooling system believed
  to be cause

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Chernobyl

• Explosions blew top off reactor building
• Radioactive particles traveled around world

• 31 immediate deaths
• 237 acute radiation sickness
• 24,000 exposed to massive dose
• Millions in surrounding areas exposed to large
  doses
• increase in thyroid cancer among children
• Birth defects

Estimated over next 50 years 16,000 deaths linked
to Chernobyl
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Chernobyl

• Area surrounding still contaminated, including
  groundwater
• will be for hundreds of thousands of years

• Sites other reactors not shut down until 2000
• When countries in west agreed to pay for cleanup
• And construction of two new reactors in Ukraine

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Future of Nuclear Energy

• Germany - 1/3 of power from nuclear power but all
  plants will be shut down by 2025 due to age and
  environmental concerns

• Some opposition
• Have to convert to new source - concerns about
  fossil fuel pollutants
• U.S. plants terrorism-target concerns
• World waste disposal issues

Palo Verde, AZ Largest Nuclear Plant in U.S.
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Radioactive Waste Management

• Low-level radioactive wastes
• Small amounts liquids, sludges, equipment
• must be isolated from environment for 500 yrs
• U.S. policy gt dilute and disperse lt bury in
  controlled and monitored areas where hydrologic
  and geologic conditions severely limit migration
• WA, NV, NM, MI, IL, OH, TN, KY, SC, NY
• But it has already been recognized in WA and TN
  that these conditions have not been met -
  containment failed and wastes seeped into
  groundwater

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Radioactive Waste Management

• Transuranic wastes
• Contaminated industrial trash clothing, tools,
  etc.
• Most from nuclear weapon production or cleanup
• From elements other than uranium with much longer
  period of extreme danger
• Isolate for 250,000 years
• Disposal site - Carlsbad, NM

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Radioactive Waste Management

• By-product wastes Carlsbad, NM
• Pilot project, being carefully monitored
• Burial depth 2150 ft in thick salt beds
• Geologically stable area
• Salt easy to mine and build rooms
• Salt flows slowly into openings and will
  naturally seal the rooms off
• Warnings above and below ground designed with
  future languages and culture changes in mind

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Radioactive Waste Management

• High-level radioactive wastes
• left with fuel that has been used
• Reprocessing more expensive than mining and
  producing new uranium
• Isolate for 250,000 years
• Yucca Mountain chosen disposal site
• Compacted tuff
• Dry region, lt5 of precipitation reaches water
  table
• Water table several hundred feet below surface
• Create repository well above water table
• Create engineered barriers also
• Serious opposition for scientific and political
  reasons

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Radioactive Waste Management
Natural Barriers
Yucca Mountain, NV near Las Vegas
Arid region- low rainfall High evaporation
Solid strong Volcanic rocks
Special natural minerals that will adsorb fluids
Deep water table below thick Unsaturated rock
formations
Engineered barriers will contain wastes
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Radioactive Waste Management

• Biggest Issue
• How can humans accurately predict geologic
  conditions for 250,000 years into the future??

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Geothermal

• Natural heat from Earths interior
• 1 of geothermal energy in accessible places of
  the Earths crust
• would 500 x the global oil and gas reserves
• Geothermal energy is currently more expensive
• than that from fossil fuel resources
• Geothermal energy is not available
• over large areas of the Earth where
• it is necessary

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Geothermal

• Hydrothermal Convection Systems - geothermal
  basin in which hot water circulates

Natural steam drives turbines in plants. Water
removed can be
recycled by injection back into reservoir
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Geothermal

• Groundwater Systems
• Groundwater typically 55F
• Cooler than air in summer and warmer than air in
  winter (in northern climates)
• Heat pumps use this difference to heat and cool
  buildings
• High initial cost to drill wells, but lower cost
  later

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Geothermal

• Environmental Impact
• Gas emissions lt1 of nitrous oxides and only 5
  of carbon dioxide emitted by comparable
  coal-burning plants
• Thermal pollution from hot wastewaters which have
  high mineral content
• Injecting wastewaters activate fractures
• Withdrawal of fluids may cause subsidence
• May impact geysers
• Nonrenewable

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Methane Hydrate

• Newly recognized potential source of natural gas
• Likely source to replace oil

Methane bubbles released as core emplaced

• Produces fewer air pollutants when burned
• Renewable

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Methane Hydrate

• Exist 3300 ft beneath oceans
• Ice-like compound of methane gas surrounded by
  cage of frozen water
• Cages result from microbial digestion of organic
  matter in sediments
• Also land deposits
• Permafrost areas of Siberia and North America
  (marsh gas)

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Methane Hydrate

• 2x as much carbon as all known natural gas, oil,
  and coal deposits on Earth IF they can be
  captured
• Difficult to mine
• Found along lower parts of continental slopes
• 0.62 miles deeper under water than current oil
  drilling rigs can safely operate
• Deposits extend even deeper

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Methane Hydrate

• Source region high pressure and extremely cold
  temps
• Not stable at lower press and higher temps it
  will decompose and get into atmosphere
• Pollution risk, methane is greenhouse gas
• Could potentially cause rapid climate change if
  large amount released
• Giant craters on sea-floor near deposits may mark
  massive degassing explosions/emissions in past
  extinction events?

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Renewable Resources Solar Energy

• All renewable resources directly related to solar
  energy
• Type most useful varies for regions depending on
  climate and geologic factors
• On a global scale 10 weeks of solar energy all
  known reserves of coal, oil, and natural gas
• On average 13 of suns original energy entering
  atm arrives at surface
• Depends on time of year and amount of cloud cover

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Solar Systems

• Passive Systems enhance absorption of solar
  energy and use yearly fluctuations without using
  mechanical power
• Overhang that blocks summer sun, but admits
  winter
• Walls designed to absorb solar energy and emit it
  to room
• Active Systems require mechanical power for
  pumps, circulation systems, etc.

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Solar Systems

• Solar technology is simple and relatively
  inexpensive
• Currently more expensive than fossil fuels
• Becoming less expensive as technology grows, and
  as cost of fossil fuels increases

Useful worldwide Japan has solar roofing tiles
that allows building to become own power plant
Unique building construction to maximize solar
collection and power use
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Solar Systems

• Environmental Impact
• Large land area required to produce large amount
  of energy negligible problem when placed on
  roofs of existing or new structures

High-technology units have larger land impact but
can be localized