Nuclear Power clean energy

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Nuclear Power clean energy
Martin Sevior, School of Physics, University of
Melbourne
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http//nuclearinfo.net

• Ivona Okuniewicz
• Alaster Meehan
• Gareth Jones
• Damien George
• Adrian Flitney
• Greg Filewood
• Technical Support
• Lyle Winton
• Reviewed by
• Dr. Andrew Martin
• Web Design
• University of Melbourne Writing Center

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Energy and Entropy

• 2nd Law of Thermodynamics
• Entropy tends to increase
• Sharing of energy amongst all possible states
• Life is in a very low state of entropy
• To exist it must create large amounts of entropy
  elsewhere. (S Q/T)
• Life requires large amounts of Energy.

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Life and energy

• Life takes energy from the sun

Life represents a 0.02 decrease in entropy
from the sun heating earth
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Energy and civilization

• Our Civilization is based on cheap energy and
  machines
• Previous civilizations utilized humans and
  animals. (Still the case for large parts of the
  world.)
• Given sufficient quantities of energy our
  civilization can generate all the products it
  needs. (Food, Health, Metals, Plastics, Water)

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Energy in Australia

• Australias Electricity needs are currently
  supplied by 44 GigaWatts of power stations.
• Our electricity demand is forecast to grow by
  over 2 per year to 2020
• On average 1.0 GigaWatts increase each year
• Equivalent to Loy-Yang B Power Station

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Energy in the World

• China (pop 1.4 Billion) growing at 10 per year.
• India (pop 1 Billion) growing at 6 per year.
• Both aspire to Western standards of living
• China likely to achieve current Australian
  standard in 2040s
• Effect will be to triple world energy
  consumption.
• Only a large scale trade embargo will prevent
  them from effectively competing with the west.

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World Energy Growth.

• Energy Growth by source

Energy Growth by region
Projections are business as usual
Source U.S. Energy Information Administration.
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How long can we keep using Oil?

• The rate of Oil usage is substantially greater
  than the rate of new Oil discoveries
• Developing Nations have become competitors for Oil

Simple extrapolation shows Oil exhausted by 2036
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Is Oil coming up against a wall?

• Australias Oil production peaked in 2000
• Will/When will World Oil production peak?

(http//sydneypeakoil.com/phpBB/viewtopic.php?t19
72)
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Global Climate Change

• The Earths atmosphere acts as a Greenhouse.
  Traps heat that would otherwise be radiated to
  space.
• Carbon Dioxide (CO2) is the 2nd largest
  contributor (and biggest driver)
• Carbon Dioxide is also the fundamental byproduct
  of Fossil Fuel consumption
• Large scale use of Fossil Fuels has substantially
  increased CO2 concentration

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CO2 increase in the Atmosphere
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Global Climate Change
Predicted world temperature changes
Past world temperature changes
The different curves are different predictions
based on different physical assumptions and
future CO2 emissions
The current CO2 concentration is unprecedented
over half a million years
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Global Temperature Measurements
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Myths about Climate Change

• Myth- Water vapour is the main source of
  Greenhouse heating.
• Residency time of water is 10 days, CO2 is 100
  years. CO2 is the driver, water vapour provides
  feedback/amplification.
• Myth - CO2 absorption lines are saturated.
• Only true at ground level. The upper atmosphere
  is sensitive to CO2 concentration
• Net effect is an additional 4 watts/m2 extra
  heat.
• No climate model shows a decrease in temperature
  with an increase in CO2

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Predictions for CO2 outputs
The developing world will likely produce more CO2
emissions than the West before 2020
Only a large scale trade embargo on China and
India and the rest of the developing world will
prevent competition and growth
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Greenhouse Emission targets

• Kyoto protocol
• Reduce Greenhouse emissions by 5.2 from 1990
  levels by 2008-2012
• This is extremely hard. eg Canada has increased
  its emissions by 20 since 1990
• Future
• Reduce greenhouse emissions by 60 from 1990
  levels by 2050 to stabilize temperature rise to 2
  C
• Can we get away with cheating?
• What if USA adopts Kyoto?

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Australian CO2 emissions
Around 50 of Australias CO2 emissions are from
electricity production.
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Total World CO2 emissions

• Total world demand for energy is expected to at
  least double by 2050
• Much is this growth is in the third world which
  needs energy to escape poverty
• The default solution to supply this energy is to
  burn more fossil fuels
• Achieving world 60 reduction in CO2 emissions
  will be impossible if this happens

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The transition.

• Having access to large amounts of cheap energy is
  vital for our civilization.
• Over the next human generation we will need to
  manage a transition from our Fossil-Fuel based
  energy sources
• The combination of resource depletion and Climate
  Change mitigation forces this.
• Getting this right is vital for the world we
  leave our children.
• I believe that this is one of the great issues
  facing this generation.

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Nuclear Energy

• About 6 Billion years ago a supernova exploded in
  this region of space.
• About 1 solar mass of hydrogen was converted to
  Helium in about 1 second
• All the elements heavier than Lithium were
  created making life possible in the solar system
• A tiny fraction of the energy was used to create
  heavy elements like Uranium and Thorium.

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Nuclear Energy

• Chemical reactions release a few electron-volts
  of energy per reaction.

Nuclear Fission releases 200 Million electron
volts per reaction
A neutron is captured by 233U,235U or 239Pu. The
nucleus breaks apart and releases 2-3 more
neutrons. These in turn can induce further
fissions.
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Nuclear energy

• The energy release from a single fission reaction
  is about one-tenth that of an anti-matter
  annihilation.
• There is as much energy in one gram of Uranium as
  3 tonnes of coal.
• The reaction produces no CO2
• So how much Uranium is present on Earth?

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Uranium Abundance.

• The Earths crust is estimated to contain 40
  trillion tonnes of Uranium and 3 times as much
  Thorium.
• We have mined less than a ten millionth of this.
• (We have extracted about half of all conventional
  Oil)
• If burnt in a 4th Generation reactor provides 6
  Billion years of energy.
• If burned in a current reactor enough for 24
  Million years.
• But most is inaccessible. How much is really
  available?

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Uranium Abundance
Proven reserves as of June 2005 amount to 3
Million tonnes, sufficient for 50 years at
present consumption rates
Rossing mine in Namibia has a Uranium abundance
of 350 ppm and provides an energy gain of 500
Extrapolating to 10 ppm provides an energy gain
of 14
4th Generation reactor (50 times more efficient
Uranium usage) provides an energy gain of 100 at
2 ppm
At least 8,000 times more Uranium can be usefully
mined using current reactors. 32,000 times more
with 4th Generation. (96 million years worth.)
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Uranium in Sea Water

• Very low concentration 3 mg/m3, but a huge
  resource 4.5x109 tonnes
• Japanese experiment recovered gt 1 Kg in 240 day
  exposure

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Nuclear Power

• Nuclear Power has been demonstrated to work at
  large scale.
• France (80 Nuke, 20 Hydro) and Sweden (50
  Nuke, 50 Hydro) have the lowest per capita
  greenhouse emissions of large countries in the
  OECD
• Australia, with its reliance on Coal-powered
  electricity, has the highest

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Nuclear Greenhouse Gas emissions

• The Nuclear Fuel cycle is complex. How much
  Greenhouse Gases are produced?

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Vattenfall

• The Swedish Energy utility operates Nuclear,
  Hydro, Wind, BioMass, Solar and Fossil Fuel
  facilities.
• Vattenfall have performed LifeCycle Analyses for
  these.
• These are described in Environment Product
  Descriptions EPD.
• Useful Worlds Best Practice reference

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CO2 emissions from Nuclear

• Vattenfall EPD calculations, Gas 400 gm/kw-hr,
  Coal 700 1000 gm/kw-hr

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Vattenfall CO2 emissions from other sources
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Nuclear Reactors

• Nuclear reactors work by purposely allowing a
  controlled chain reaction.
• This is controlled by adjusting the neutron
  multiplication factor.
• Current nuclear technology mostly employs Light
  Water Reactors which burn Uranium enriched in
  235U from its natural 0.7 to around 3
• The reactor is shutdown and fuel is changed after
  the 235U abundance has fallen to around 1.2
• This typically occurs every 2 years.
• So every 2 years 60 tonnes of fuel is replaced
• Compare to Coal fired plants which burn 3000
  tonnes of fuel every day.

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Science of Nuclear Power

• Cross sections for fission

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Thermal Nuclear Reactors

• Neutron cycle in 235U and 238U mixture

Self-sustaining chain reaction.
Requires neutron multiplication factor k 1.00000
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Control of Thermal Reactors

• Controlled via absorption in 238U

At least 20 times more 238U than 235U

• At higher temps
• Doppler broaden
• Harder spectrum
• Increases 238U absorption

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Control of light water reactors

• Delayed neutron emission
• 0.7 neutrons emitted after beta decay (8
  seconds)
• Negative temperature coefficient
• (k reduces with T)
• Negative void coefficient.
• Loss of coolant through bubble formation or other
  means, means no further moderation and a decrease
  in reactivity.
• Massive loss of coolant
• Decay heat problem
• Second generation reactors have multiple active
  backup and containment.

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Radiation

• Nuclear Energy produces vast amounts of
  radioactivity which is extremely dangerous.
• Effects of Radiation
• Cell Death or Apoptosis
• Cancer Induction (0.06/Sv)
• Genetic Damage to Future Generations (0.02/Sv)
• However we are all exposed to radiation every day
  of lives. It cannot be avoided.

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Radiation Exposure
Typical background exposure is 3000
micro-seiverts per year
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Nuclear Safety

• Typical large Nuclear Power Plant contains 10
  billion Giga-Becquerel's of activity.
• 1 Giga-Becquerel typically leads to an wanted
  exposure.
• Nuclear Power Plants contain vast amounts of
  dangerous material.
• Safely handling this is a significant challenge.

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Safety Reactivity Control

• Nuclear reactors work by keeping the neutron
  multiplication factor to be 1
• Multiplication factor is adjusted by changing the
  configuration of neutron absorbers.
• This possible because 0.6 of neutron emission is
  delayed by a few seconds
• Light water reactors naturally slow down when the
  temperature increases negative temperature
  coefficient
• Light water reactors naturally slow down if there
  is a loss of coolant negative void coefficient

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Safety Reactivity Control

• Accidents
• Numerous things can (and do) go wrong during
  operations.
• These are normally handled through routine
  adjustments of the reactor parameters
• Worst case is massive loss of primary coolant.
• Current reactor handle this with multiple
  redundant systems to pump water through the core.
  Active Safety systems
• Next generation reactors employ Passive features
  which rely on Laws of Physics to ensure safe
  shutdown.

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Safety

• The U.S. Nuclear Regulatory Commission (NRC)
  requires reactors to be design so that Core
  damage accidents occur less than 1 in 10,000
  years of reactor operation.
• In this case the radiation is contained within a
  safety shell. (50 cm reinforced steel surrounded
  by 1.3 meters of concrete.)
• Current Reactors are estimated to have core
  failure rates of 1 in 100,000 years of operation.
• New reactors under investigation for deployment
  are estimated to have failure rates of 1 in 2
  million years of operation.

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Safety

• The western nuclear power industry has the best
  safety record of any large scale industrial
  activity.
• Within the US, communities living close Nuclear
  Power plants are overwhelmingly in favour of
  continued operation.
• There is strong competition between communities
  to be the location of New Reactors.
• As of February 2006, the NRC had received
  expressions of interest for 17 new Nuclear
  Power Plants in the USA. All have local support.

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Safety - Chernobyl

• The Chernobyl reactor had a number terrible
  deficiencies compared to Western reactors.
• No containment structure
• Positive void coefficient at low power.
• Control rods were graphite tipped!
• As part of an experiment, operators switched off
  the safety interlocks
• Reduced the Power of reactor to low level.
• Strenuously tried to increase the power in an
  unconventional operating environment.
• Fundamental Failure of Safety Culture.

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Nuclear Power Costs

• Total cost Cost of Capital Operating Costs
• Operating costs of current plants are the lowest
  of all forms except Hydro (typically 1.5
  cents/KwHr).
• New Nuclear plants are projected to cost less
  than 1.5 US Billion dollars and operate for 60
  years.
• BUT best new plants have First of their Kind
  risks
• Projected Electricity costs are 2.2-3.8 US
  cents/KW-Hr (but up to 6 US cents/KW-Hr)
• Current Australian Eastern Australian coal
  electricity costs around 2.2 - 4 US cents/KW-Hr
• Clean Coal expected to add 2 cents/Kw-Hr

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Previous generation Nuclear Power

• In the USA Nuclear Power plants turned out to be
  FAR more expensive.
• Plant cost was 3 5 Billion for 1 GW
• Operational availability was around 60
• Design deficiencies NRC mandated changes
• Two stage licensing
• Fragmented industry for construction
• Fragmented industry during operation

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Current US experience

• Availability has increased to more than 90
• Specialist companies now operate the US fleet.
• Costs average 1.6 cents/KW-Hr

• Nuclear Industry expects new plants cost 1 1.5
  Billion per GW

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Nuclear Waste

• Nuclear Power plants produce 30 tonnes of high
  level waste/year.
• 95 of the energy in the fuel remains
• Waste consists of short-lived light fission
  products and long-lived trans-Uranics.
• Current waste handling procedure is to leave
  spent fuel in cooling ponds for 20 years.
  Followed by either dry storage, reprocessing or
  long term geologic disposal

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Geologic Disposal

• 3 mature proposals, Sweden, Finland and USA.
• Unprocessed waste requires isolation for 100,000
  years
• The Nordic proposal consists of a multiple
  barrier burial deep in wet Granite Rocks
• The US proposal consists of dry burial
  underground with easy retrieval.

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Finish proposal
Spent Fuel is placed in Cast Iron Insert. Then in
copper canister Canister is embedded in Bentonite
clay Then buried in Granite rock 500 meters
underground
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Multiple Barriers

• The fuel itself retains the fission products.
• Cast iron insert
• Studied of Copper in anaerobic environment show
  stability over 100,000 years
• Bentonite Clays swell on wetting removing oxygen.
  Also retain fission products.
• Granite and infill isolate waste from the
  environment. Granites show affinity for
  trans-Uranics
• Oklo natural reactor show fission products have
  not moved over 1.8 Billion years.
• Strong scientific case that nuclear can be
  isolated

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Nuclear Waste

• There is a strong Scientific case that Nuclear
  waste can be safely sequestered.
• However it is expensive and takes a long time to
  plan.
• The USAs Yucca mountain repository is
  insufficient for even the current generation.
• Factor of 5 10 expansion of the nuclear
  industry would be helped with an improved waste
  management system.
• UREX reprocessing and fast-neutron Burner
  Reactors 2006 GNEP initiative

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Nuclear Proliferation

• A single large Nuclear Power plant produces large
  amounts of 239Pu. More than enough for 100s of
  nuclear weapons.
• However over time they also produce a significant
  amount of 240Pu.
• Too much 240Pu makes it very difficult to
  construct a Nuclear Weapon.
• Weapons Grade Plutonium is defined to have less
  than 7 240Pu.

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Nuclear Proliferation
After 4 months operation in a Light Water reactor
the 240Pu concentration exceeds 7
Operating a Commercial Light water reactor under
the IAEA Additional Protocol is a low
proliferation risk activity
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East Australian Electricity demand
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Alternatives - Renewables

• The Earth receives vast amounts of solar energy.
  In principle more than enough for an advanced
  civilizations energy requirements.
• Energy from the sun can be harnessed through
• Hydro-Electricity
• Biomass (Burning organic products.)
• Wind
• Solar Thermal including passive heating
• Solar PhotoVoltaics
• All these can and are making a significant
  contribution to our energy needs
• Plus GeoThermal (uses Earths Radioactive
  resources)

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Renewables

• However its not clear that these can meet all
  our energy needs.
• Hydro is basically exhausted in Australia and
  faces environmental concern elsewhere
• Biomass cannot supply both food and fuel in many
  parts of the world. (Current energy use is 10 of
  total global photosynthesis)
• Wind is not suitable for large scale base-load
  generation. (Plus is more expensive.)
• Solar-electric is also not suitable for Base-Load
  generation. (Plus is also more expensive.)
• Limited availability for GeoThermal

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Wind Variability
CSIRO study assuming 3 GW of generating capacity
spread over SA, Vic and NSW.
Best sites give 30 utilization
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Wind energy density

• Average output is at best 1.3 MW/ km2

No trees allowed over a wind farm
Extra costs involved in handling varying supply
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Clean Coal

• Idea is to capture CO2 emissions and store them
  deep underground.
• Sufficient for 80 years of current CO2
  production.
• Challenge Each year a 1 GW Coal plant produces
  around 1 million tonnes of CO2 gas.
• This must be isolated from the environment for
  tens of millions of years.
• Researchers are quite optimistic and
  demonstration plants are expected by 2012
• Can also produce Hydrogen very cheaply

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New nuclear technology

• Variety of new reactor designs that are at least
  50 times more efficient and can destroy the
  Trans-Uranic waste. (4th Generation)
• Waste is reduced to 1 tonne per year. Isolation
  time of 500 years.
• Hydrogen gas can be cheaply generated via
  thermo-chemical reactions using the High
  Temperature reactors.
• This can be used in place of Petroleum for many
  transport needs.
• Projected cost equivalent to 40 cents/litre
  petrol.

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Advanced (Fast) Reactors

• Use unmoderated (or lightly) neutrons.
• Avoids neutron losses plus can directly fission
  238U and other even actinides

Can burn long lived radioactive waste
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Fourth Generation reactors

• The Gas-Cooled Fast Reactor (GFR)
• Very-High-Temperature Reactor (VHTR)
• Supercritical-Water-Cooled Reactor (SCWR)
• Sodium-Cooled Fast Reactor (SFR)
• Lead-Cooled Fast Reactor (LFR)
• Molten Salt Reactor (MSR)

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Goals of the 4th Generation

• They efficiently utilize Uranium
• Destroy a large fraction of nuclear waste from
  current reactors via transmutation.
• Generate Hydrogen for transportation and other
  non-electric energy needs.
• Be inherently safe and easy to operate.
• Provide inherent resistance to Nuclear Weapons
  proliferation.
• Provide a clear cost advantage over other forms
  of energy generation.
• Carry a financial risk no greater than other
  forms of energy generation.
• Not before 2020 at the earliest

If successful will provide energy indefinitely
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Accelerator Driven Systems

• Use a very high powered accelerator to provide
  neutrons to a subcritical assembly
• No possibility of a melt-down.
• Provides an energy gain and
• Destroys long lived isotopes through
  transmutation.
• Requires around 50 MW of proton beam (current
  best around 2 MW)

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Australian Context

• Australia has the largest CO2 emissions per
  capita in the OECD (27 tonnes Per Person)
• Finland has CO2 output of 8.6 tonnes/person
• Australian Per Capita energy consumption is
  approximately the same. Electricity is 60 more.
• Finland (and Sweden and France) is where
  Australia should be by 2050.
• Finland continues to invest in Nuclear Power

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Planning Issues

• Australia is a democratic and open society with
  many opportunities for citizens to influence
  local developments.
• Top down and imposed decisions can face fierce
  opposition (cf some Wind Power.)
• Any development of large scale facilities must
  provide net benefits to locals
• Time scales of the order of many years are
  typical.

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Regulatory Issues for nuclear

• Overseas (particularly US) experience shows the
  importance of correct regulatory framework.
• Australia does not have this.
• Need to achieve economies of scale for light
  water reactors
• Operating a reactor requires significant
  expertise. Need to establish and monitor World
  Best Practice

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My opinion.

• Credible case for Nuclear Power
• Only Nuclear Power can displace the huge Fossil
  Fuel base-load electricty requirements.
• But Nuclear Industry needs to demonstrate
  Advanced Passive reactors work and are the prices
  advertised.
• For Australia, going the Nuclear route would
  require a significant consensus that this is the
  best way forward on the part of Society.

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Recommendations

• We should take advantage of economies of scale
  and deploy a significant number of reactors (more
  than say, six 1 GW reactors) so that the costs of
  waste disposal and fuel enrichment can be shared.
• Local communities should be encouraged to bid for
  nuclear investment. Decisions should not be
  imposed.
• An Australian Nuclear Industry must be pro-active
  in engaging with the World Community and employ
  World Best Practice levels of Safety and
  operations.
• We would need an independent and pro-active
  regulatory framework to oversee the operations of
  a Nuclear Industry.
• The activities of the Regulators and the Industry
  must be open to the public and all decisions
  should be fully transparent.
• We must invest in research to find and build a
  suitable site for geologic disposal of waste.
• We must decide on appropriate means of
  transporting the waste to the site.