Transcript Slide 1

Nuclear Power:
facts, questions, risks,
and the research needed
József Pálinkás
President, Hungarian Academy of Sciences
3rd Energy Forum
Budapest, October 28, 2008
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Nuclear power today – facts – 1
• first commercial nuclear power stations started
operation in the 1950s
• today: some 435 commercial nuclear power
reactors in 30 countries, with 370 GW of total
capacity
• 16% of the world's electricity production as baseload power; almost 24% of electricity in OECD
countries, 34% in the EU
• as much electricity from nuclear today as from all
sources worldwide in 1960
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Nuclear power today – facts – 2
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World energy needs
• greatly increasing energy needs, especially for cleanlygenerated electricity
• electricity demand likely to almost double from 2004 to
2030
• electricity is essential for development of China, India, etc.
• energy saving: very important but cannot solve growing
electricity demand
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Energy sources
• fossil fuel: exhausted on a longer time scale; greenhouse
gases
• renewables: may contribute but are not a solution alone;
high generating costs (except hydro)
• nuclear:
– environmentally benign
– large scale base load
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Renewable energy sources
• diverse: wind, solar, tidal, wave, hydro, geothermal,
biomass
• not for large-scale, continuous power generation, except
hydro
• growing use, but role limited by intermittent nature
• price?
• appealing where demand is for small-scale, intermittent
supply
• OECD: about 2% of electricity is from renewables other
than hydro, expected to increase to 4% by 2015
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Greenhouse gases
• CO2 causes half of the human-contributed portion of
global warming
• nuclear reduces world CO2 emission by
– about 2.5 billion tonnes per year relative to coal-fired generation
– about 2 billion tonnes per year relative to present fuel mix
• 2007 IPCC report:
– restriction of temperature rise to under 3°C requires an increase
in non-carbon global electricity generation from 34% to 48 – 53%
by 2030
– other non-carbon sources apart from hydro are projected by
IPCC to contribute some 12 – 17% of global electricity
generation by 2030
– nuclear is projected by IPCC to grow from 16% now to 18% of
the increased demand, ie. from 2650 TWh/y to some 6000
TWh/yr  more than doubling by 2030
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Safety of nuclear reactors
• strong awareness of the potential hazard of both nuclear criticality
and release of radioactive materials
• two major reactor accidents in
more than 12,700 cumulative
reactor-years of commercial
operation in 32 countries :
– Three Mile Island, contained
without harm to anyone
– Chernobyl, involving an
intense fire without provision
for containment
•
risks from nuclear power plants (consequences of an accident or
terrorist attack) are minimal compared with other commonly accepted
risks: nuclear power plants are very robust
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Ageing of nuclear reactors
• original design: 30 or 40 years operating lives
• characteristics of systems, structures and components
change gradually
– corrosion or degradation to a low level of efficiency  replacement
– obsolescence: eg. analogue I&C  replacement or maintenance
– material properties degrade due to heat and neutron irradiation
(eg. pressure vessel of some early Russian PWR’s)  careful
checking
• periodic safety reviews (IAEA safety convention and safety
culture)
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Nuclear fuel
• U: common metal (rocks, seawater)
• known economic uranium resources = 5.5 million tonnes
• IAEA’s and NEA’s estimate: conventional resources = 10.5 million
tonnes
• enough for 200 years' supply at today's rate of consumption
80 years at the expected rate of increased
consumption
• optimization of fuel usage: fast reactors produce more fuel than they
use  combined fleet of thermal and fast reactors
• steady reprocessing required (capital-intensive but well-proven)
• Generation-IV project: for producing sustainable nuclear energy
• non-proliferation!!!
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Waste management
• radioactive waste is the most disputed problem of the use of nuclear
• nuclear industrytakes full responsibility for all its wastes
fully costs this into the product
• the amount of radioactive wastes is small
• low and medium level waste can be disposed without major
problems
• high-level wastes (HLW):
– from the "burning" of uranium in a reactor
– contain the fission products and transuranium elements
generated in the reactor
– highly radioactive and hot, so requires cooling and shielding
– account for over 95% of the total radioactivity produced by
electricity generation
– two distinct kinds: used fuel itself in fuel rods, and separated
waste from reprocessing the used fuel
• safe methods for the final disposal of HLW are technically proven
• international consensus: deep geological disposal
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Disposal of spent fuel and HLW – 1
• about 270,000 tonnes of spent fuel in storage, much of it
at reactor sites (about 90% in ponds, the balance in dry
storage)
• annualy about 12,000 tonnes, 3000 tonnes of it
reprocessed
• first surface storage for 40-50 years  there is time to
find the best technology and logistics
• selection of appropriate deep geological repositories is
now under way in several countries, first expected to be
commissioned some time after 2010
• Finland and Sweden: well advanced for direct disposal of
used fuel
• US: final repository in Nevada
• proposals for international HLW repositories in optimum
geology – Australia or Russia are possible locations.
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Nuclear energy in Hungary - 1
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4 VVER-440/V-213 nuclear reactors Paks: more than 1/3 of electricity
Soviet design, began operating between 1982 and 1987
fuelled with Russian fuel
original design lifetime: 30 years, but in November 2005 Parliament
endorsed plans to extend lifetimes by 20 years, to 2032-37
originally 440 MWe gross
by early 2009 upgraded and modified to 500 – 510 MWe gross
repository of low and medium level waste almost ready
dry storage facility to store temporarily the spent fuel
spent fuel and HLW will be probably deposited in the Mecsek mountain,
geological investigations are underway
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Research objectives
Topical problems
• Current and evolutionary light water reactors:
safety knowledge is mature
ageing phenomena
supercritical water cooled reactors
• Fuel cycle:
how to close the fuel cycle
advanced reprocessing, partitioning and transmutation
• Generation-IV reactors:
fast reactors with liquid metal or gas cooling
• Non-power uses of nuclear energy:
high temperature reactors for hydrogen production
These objectives should be met by R&D outlined in the Strategic Research
Agenda of the EU Sustainable Nuclear Energy Technology Platform.
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Research organization
Expected basic developments
• revolution in materials science (connecting microscopic and macroscopic
parameters)
• revolution in computation (advanced simulation tools, connecting the
mathematical physics of various disciplines)
• knowledge management (new generation of nuclear experts is strongly
needed, the knowledge on nuclear safety is a very high value asset that
should not be lost)
Research in Hungary
• Nuclear safety research is well integrated into the European Research Area.
• The Academy of Sciences intends to strengthen energy research, especially
research on sustainability and the proper energy mix.
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Summary
• Nuclear energy will remain an important contributor to
electric energy production in the 21st century.
• In order to reach sustainable nuclear energy production,
a combined fleet of thermal and fast reactors is needed
(Generation-IV project).
• The non-proliferation considerations are substantial.
• Spent fuel and high level radioactive waste disposal
problems should be solved on the medium term. The use
of fast reactors may largely ease the solution of this
problem by diminishing the amount of long lived isotopes
in the waste.
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