Climate Change and the Future of Nuclear Energy

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Climate Change and theFuture of Nuclear Energy

• Steve Fetter
• School of Public Policy
• University of Maryland
• UMCP Physics Department
• 30 October 2007

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What Is the Energy Problem?

• Security too dependent on Middle East oil
• Oil is a commodity traded on open markets
  potential for mischief by a single supplier
  (e.g., Iran) is limited
• Middle East oil is a modest fraction of U.S.
  (10) and world (25) consumption
• Security risks are related to large flows of
  money to undemocratic and potentially hostile
  governments

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All Countries
Persian Gulf
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U.S. Oil by Region of Origin, 2005
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(No Transcript)
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What Is the Energy Problem?

• Security too dependent on Middle East oil
• Scarcity we are running out of oil and other
  energy resources
• era of cheap oil and gas may be ending, but
• huge fossil resources remain that can be
  recovered (and converted to portable fuels) at
  reasonable cost

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Fossil Fuel Resources
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What Is the Energy Problem?

• Security too dependent on Middle East oil
• Scarcity we are running out of fossil fuels
• Sustainability carbon emissions from continued
  burning of fossil fuels will have disastrous
  consequences

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World Energy Consumption
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World Carbon Emissions
GtC
80
Compare to 590 GtC in the preindustrial atmosphere
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CO2 Concentration
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Global Average Temperature
Total increase since 1850 0.6-1 C Rate of
increase since 1950 1-1.6 C/century 11 of last
12 years were warmest on record
Thermometers
Tree rings, etc.
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Climate Change Imperative

• The ultimate objectiveis to achieve
  stabilization of greenhouse gas concentrations in
  the atmosphere at a level that would
• prevent dangerous anthropogenic interference
  with the climate system. Such a level should be
  achieved within a time-frame sufficient to allow
  ecosystems to adapt naturally to climate change,
  to ensure that food production is not threatened
  and to enable economic development to proceed in
  a sustainable manner.
• Article 2, UNFCCC

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The Stabilization Goal

• Dangerous interference now seems inevitable
  the challenge is to avoid catastrophic change
• Doubling of CO2 (from 275 to 550 ppmv) would lead
  to an equilibrium global-average temperature
  increase of 2 to 4.5 ºC
• at low end, equal to EU goal of 2 ºC
• at high end, comparable to increase at end of ice
  age
• severe impacts likely, but true
  catastrophecollapse of THC or WAIS, runaway
  feedbacksseems unlikely
• Dont forget the other GHGs

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Other Greenhouse Gases

• GHGs other than CO2 now equivalent to 80 ppmv
  CO2 stabilization at lt100 ppmv unlikely, so
• 450 ppmv CO2 equivalent doubling

80 ppmv equiv.
CO2 CH4 N2O halocarbons
100 ppmv
CO2 only
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Equivalent Doubling Stabilization Scenario
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Carbon Emissions
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Emission Scenarios
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Carbon Mitigation Requirement2010-2050
Required reductions 7 to 18 GtC/y in 2050
(60-80 below reference scenarios) For
comparison 1000 large (1 GWe) coal-fired power
plants emit 1 GtC/y
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Major Mitigation Options

• Demand reductions
• Increased energy efficiency
• Taxes or cap-and-trade carbon permit system
• Renewables
• Wind
• Solar
• Biomass
• Fossil fuels with carbon sequestration
• Nuclear

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Alternatives to Nuclear
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Advantages of Nuclear

• Largest installed base of carbon-free supply
  alternatives, extensive operating experience and
  industrial base
• Unlike wind and solar, can provide baseload
  electricity also industrial heat
• Unlike biomass and coal with sequestration, small
  resource requirements
• But lots of nuclear will be needed to make a
  significant contribution

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Growth Scenario for Nuclear Provides 25 of
carbon reduction needed for stabilization at an
equivalent doubling
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Key Issues for Nuclear

• Cost
• market penetration is highly sensitive to cost
• Safety
• serious accident could halt nuclear expansion
• Waste
• political resolution sufficient to allow
  expansion
• Proliferation
• expansion must not make it significantly easier
  for countries or groups to acquire weapons

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Cost of Electricity, Current US Reactors
(2004/MWh)
Average COE, 2005, all sources
30 40 50 60 70 80 90 100
110 120 130 140
Koomey Hultman (submitted) 2007
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Wheres the Learning Curve?
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Future Costs

• Estimated cost of electricity (COE) for a new US
  nuclear reactor

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Nuclear v. Alternatives (/MWh)
plus backup/storage above 20 of load
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Safety

• New LWRs estimated to have accident probabilities
  at least 10x less than current LWRs 10x growth
  possible without increased overall risk
• core damage lt 106 per reactor-year
• core damage loss of investment
• large release lt 107 per reactor-year
• large release one or more off-site casualties
• If correct, lt3 risk of core damage, lt0.3 of a
  large release in next 50 years in growth scenario
• safe enough?

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Safety

• Analysis presumes proper reactor operation and
  maintenance by well trained and highly
  disciplined staff, overseen by independent,
  capable, and diligent regulatory body
• Much of growth in electricity demand years will
  occur in countries without this safety culture
  an accident anywhere is an accident everywhere
• In the near-term, expand training and technical
  assistance programs
• In the longer term, develop inherently safe
  reactors, far less vulnerable to operator error

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Waste Disposal

• Geological disposal is cheap
• The cost of building and operating the Yucca
  Mountain repository in Nevada is financed by a
  1/MWh charge2 of the cost of nuclear-generated
  electricity
• Geological disposal is safe
• Calculated doses are below current EPA limits for
  100,000 yr for maximally exposed individual
• Doses in other geologies could be much lower

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Calculated Doses for Maximally Exposed Individual
at YM
occupational limit
CT scan
natural background
EPA limit
cross-country flight
300 simulations
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Waste Disposal

• Geological disposal is not easy
• no disposal of spent fuel or high-level waste has
  occurred, in US or elsewhere else
• seen as barrier to expansion of nuclear power,
  but
• There is no urgency
• spent fuel can be stored safely and inexpensively
  in dry casks for 50-100 years
• ample time to license repository or consider
  other options

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Two of these casks can store the spent fuel from
operation of large reactor for one year
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Waste Disposal

• Yucca Mountain is limited by law to 70,000 tons
  of spent fuel
• equal to spent fuel discharged by current
  reactors by 2010 (plus defense waste)
• 500 reactors (100 of U.S. electricity
  consumption) would discharge 20 t/y, leading some
  to claim one YM needed every 7 years, but
• physical capacity of YM is 9 times greater lots
  of additional, similar land available nearby

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Proliferation

• Fresh fuel, reactors, spent fuel are easy to
  safeguard, highly resistant to diversion and
  theft
• Uranium enrichment
• separative work required to fuel 1 reactor with
  LEU could be used to produce HEU for 25
  bombs/year
• HEU production readily detectable in known
  facilities, but clandestine enrichment is very
  difficult to detect
• Reprocessing
• spent fuel discharged by 1 reactor contains
  enough Pu to build 25 bombs/year--protected by
  high radiation
• if spent fuel is reprocessed, separated Pu or Pu
  fuels is vulnerable to diversion and theft

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Bush Administrations Solution Global Nuclear
Energy Partnership

• Promote global expansion of nuclear energy while
• reducing risk of nuclear proliferation
• minimizing nuclear waste
• Key elements
• limit enrichment, reprocessing to supplier
  states
• suppliers provide fresh fuel to user states,
  take back spent fuel
• suppliers reprocess spent fuel, transmute TRU in
  burner reactors

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Global Nuclear Energy Partnership
Reliable fuel services leasing and take-back
Enhanced safeguards
Small-scale reactors
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A Critique of GNEP

• Proliferation
• how do we limit number of supplier states?
• Economics
• increased cost who will pay? user states?
  ratepayers? taxpayers?
• Waste
• reduces required repository space (at a very high
  price), but repository still needed

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Reliable Fuel Services

• Supplying fresh fuel, taking back spent fuel
  should discourage enrichment and reprocessing
• focus has been on guaranteeing supply of fresh
  fuel
• key to success is guaranteed take-back of spent
  fuel
• Impact of voluntary arrangements will be limited
• does not address hard cases like Iran, which
  rejected a lease/take-back offer from Russia
• Argentina, Australia, Brazil, Canada, South
  Africa, Ukraine interested in being suppliers

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Proliferation-Resistant Recycle?

• Protect Pu by keeping it with mixed with other
  transuranics (TRU NpPuAmCm)
• dose rate from TRU 60x higher than pure Pu, but
  only 0.05 rem/h (50,000x less than spent fuel,
  2000x less than IAEA standard)
• TRU can be used directly in weapon, or Pu
  separated from TRU in glove box using
  straightforward chemistry
• Am and Cm complicate material accountancy
• Process could be modified to produce pure Pu
• No reprocessing/recycle can be proliferation
  resistant but why bother trying if it is
  restricted to countries considered safe?

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Increased Cost

• Fast reactors (needed to burn TRU) likely to cost
  more than thermal reactors
• GE estimates 30 more per GW, MWh
• Proven fast-reactor fuels also produce TRU
• many recycles needed to burn up TRU
• fastthermal capacity 11
• new infertile fuels needed to go as low as 13
• Average cost of electricity 15 higher
• 100 million/year per GW of total capacity
• who will pay? user countries? supplier countries?
• who will build fast reactors?

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GNEP Fuel Cycle
U3O8
20 t/y LEU fuel
UF6
LEU
Conversion
1 GWe ? 33 ? 85
20 t/y spent LEU 1.2 TRU
HLW
240 kg/y TRU
User Countries
Supplier Countries
860 kg/y TRU
Repository
620 kg/y TRU
1 GWe ? 38 ? 85 CR 0.7
HLW
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Waste Disposal Benefits?

• Recycle and burning of TRU reduces long-term heat
  load and toxicity of waste
• geologic repository (e.g., YM) still needed
• required repository area reduced by 5x, at high
  cost
• Separation of long-lived fission products (Sr,
  Cs) could reduce repository area by additional
  20x
• would require safe storage for 300 years
• storage of spent fuel for 300 years much
  simpler, cheaper

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Policy Alternatives

• Spent-fuel take-back is key incentive to
  voluntarily forego enrichment, reprocessing
• promote national take-back and international
  repositories for waste disposal
• Voluntary arrangements will not be sufficient
  new binding arrangements are needed
• Article IV of NPT recognizes inalienable right
  of all the Parties to use of nuclear energy for
  peaceful purposes
• Article VI of NPT, parties undertake to pursue
  negotiations in good faith on nuclear
  disarmament
• Could restrictions on enrichment and reprocessing
  be linked to pursuit of prohibition of nuclear
  weapons?

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Technology Alternatives

• No need to press for commercialization of fast
  reactors and/or reprocessing/recycle
• Alternative concepts that might have substantial
  advantages over LWRs
• High-temperature gas-cooled reactors
• higher efficiency lowers cost, H2 production
  possible
• potential safety and nonproliferation advantages
• Small, long-lifetime sealed-core reactors
• poor economy of scale, but mass production could
  bring unit cost down
• potential safety and nonproliferation advantages

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Questions?
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Resource Extension?

• TRU recycle would extend U resources, facilitate
  transition to breeder reactors
• But low-cost uranium resources sufficient to
  support nuclear expansion through end of century
  on once-through fuel cycle
• Better to defer reprocessing, recycle, breeder
  reactors until economical
• Spent fuel can be stored until recycle is
  economical Pu isnt thrown away

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Cumulative U consumptionLWRs with direct disposal
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Increase in Repository Capacity
Assumptions 200 C drift wall, 100 C mid-drift 50
GWd/t spent fuel, separation/emplacement at 25
years, closure at 100 years Phillip Finck,
Benefits of the Closed Nuclear Fuel Cycle, 10
March 2006
Fraction of Sr, Cs in waste
Fraction of Transuranics (Pu, Am, Cm) in Waste