28/10/2008energy_pálinkás1 Nuclear Power: facts, questions, risks, and the research needed József...

28/10/2008 energy_pálinkás 1

Nuclear Power:facts, questions, risks,

and the research needed

József PálinkásPresident, Hungarian Academy of Sciences

3rd Energy Forum

Budapest, October 28, 2008


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 base-load 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


Nuclear power today – facts – 2


World energy needs

• greatly increasing energy needs, especially for cleanly-generated 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


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


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


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


Safety of nuclear reactors

• 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 orterrorist attack) are minimal compared with other commonly

acceptedrisks: nuclear power plants are very robust

• strong awareness of the potential hazard of both nuclear criticality and release of radioactive materials


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)


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 increasedconsumption

• 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!!!


Waste management• radioactive waste is the most disputed problem of the use of nuclear • nuclear industry takes 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


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.


Nuclear energy in Hungary - 1• 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


Research objectivesTopical problems• Current and evolutionary light water reactors:

safety knowledge is matureageing phenomenasupercritical water cooled reactors

• Fuel cycle: how to close the fuel cycleadvanced 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.


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.


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.

28/10/2008energy_pálinkás1 Nuclear Power: facts, questions, risks, and the research needed József...

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