nuclear energy ari mcguirk, ayad muhammad, jessica scarbrough
TRANSCRIPT
Nuclear EnergyAri McGuirk, Ayad Muhammad, Jessica Scarbrough
Overview• History
• Electricity Generation
• Reactor Types
• Environmental Implications
• Economic Implications
• Political Repercussions
• Conclusion
Pre WWII• Research fueled by German,
Russian and British efforts to achieve self-sustaining fission reaction.
• 1939- conceptualization of critical mass by Francis Perrin.
• USSR- established ten physics institutes, purged by Stalin.
• Germany’s subsequent invasion of Soviet Union forced USSR to consider nuclear energy for military applications.
British Progression WWII provided necessary
impetus for progress.
Frisch-Peierls Memorandum- experimental proof that chain reaction was possible.
Churchill wanted weaponization ASAP.
U.S. uninvolved until December 7, 1941
Manhattan Project Production plants,
process development, nuclear facility designs underway immediately after Pearl harbor.
1942- First man-made, controlled nuclear chain reaction at University of Chicago.
1945- Hiroshima and Nagasaki, end of WWII.
Post WWII Nuclear energy used for
electricity generation.
Cold war spurred new technologies.
1951- Experimental Breeder Reactor, first to produce measurable amount of electricity in Idaho.
1953- Eisenhower’s “Atoms for Peace”
ModernityHuge advancements in 50’s and 60’s.
By 1964, US, Canada, France, USSR among nations with operational nuclear reactors.
Decline during 70’s until 2000’s.
Climate change reinvigorating subject.
Several Asian countries spurring their nuclear programs- China, India, S. Korea.
Energy GenerationTwo ways of generating nuclear energy:
Nuclear fusion
Energy GenerationExamples of nuclear fusion:
• Fusion is an unstable process that requires a tremendous amount of energy
• Currently no commercial reactor that generates electricity from fusion.
• Sun generates 3.86 x 10^26 watts per second
Energy GenerationNuclear fission
Energy GenerationNuclear fission is used in modern commercial
nuclear power plants.
Inside the Nuclear Reactor• Uranium, a naturally
occurring radioactive element, is the primary fuel, particularly the isotope U-235.
• Atoms of U-235 are bombarded with neutrons to split and release heat in the presence of a moderator (usually water) to control reaction.
• The heat makes water steam and drive a turbine to generate electricity.
Nuclear Reactor Types
Two main types:
Water moderated
Heavy-water
Light-water
Pressurized water reactor
Most common type
Boiling Water reactor
Graphite moderated
Gas-cooled
Water-cooled
Light-water graphite-
moderated reactor
Pressurized Water Reactor
Other type of reactors:
Differences: Water vs. Graphite
moderated The moderators slow down
the neutrons allowing them to sustain a nuclear chain reaction
Reaction occurs when a slow neutron hits an atom and the atom quickly expels another neutron
75% of world’s reactors us light-water
20% use graphite
5% use heavy-water
Water vs. Gas coolant
These are used to
prevent the reactor from
over heating.
The water or gas
transfers heat away from
the core of the reactor
Most common coolant is
light-water
World Over-view of Reactor TypesNuclear power plants in commercial operation Reactor type Main Countries Number GWe Fuel Coolant Moderator
Pressurised Water Reactor (PWR)
US, France, Japan, Russia, China
273 253 enriched UO2
water water
Boiling Water Reactor (BWR) US, Japan, Sweden 81 76 enriched UO2
water water
Pressurised Heavy Water Reactor 'CANDU' (PHWR)
Canada 48 24 natural UO2 heavy water
heavy water
Gas-cooled Reactor (AGR & Magnox)
UK 15 8
natural U (metal), enriched UO2
CO2 graphite
Light Water Graphite Reactor (RBMK & EGP)
Russia 11 + 4 10.2 enriched UO2
water graphite
Fast Neutron Reactor (FBR) Russia 2 0.6 PuO2 and UO2
liquid sodium
none
TOTAL 434 372
Environmental Impacts
• No CO2 emissions
• Small land area
• Efficiency between 33-
45%
Environmental Impacts cont.
• Requires fossil fuels to
mine and transport
uranium
• Needs water
• Nuclear Waste concerns
• Accidents are deadly
Economic Implications Nuclear Energy is ~35% efficient with
a capacity factor of ~90%.
Very high capital costs $4540/kW compared to $3500/kW
for coal. Labor intensive, time consuming
and high construction costs.
Very low operating Costs Uranium is cheap and abundant.
Fuel costs do not affect price much, which means electricity is cheap.
Fuel can be reused.
Ambivalent external costs Carbon emissions are very low. Accidents are rare but very
destructive. Improper disposal of waste may
have serious social implications.
Political ImplicationsWho is allowed to retain nuclear warheads?
Who is allowed to utilize nuclear energy for electricity generation?
Who establishes policy over a nation’s nuclear program?
Why?
Warheads vs ElectricityWarheads Electricity (2012)
France- 75%
Slovakia- 54%
Belgium- 51%
Ukraine- 46%
Hungary 46%
Sweden- 38%
Slovenia- 36%
France Scheduled to reduce to
50% by 2025.
Largest net exporter of electricity due to low cost of generation.
17% of their electricity is from recycled nuclear fuel.
Building first Gen. III reactor.
58 reactors supplying 416 kWh in 2014.
Iran Located in oil laden
Middle East.
Possesses single nuclear reactor.
Possesses zero nuclear weapons.
Subject to sanctions designed to deter their nuclear weapons program.
Sanctions Imposed on Iran by U.N. Security Council
Block the transfer of weapons, components, technology and dual use items to Iran’s prohibited nuclear and missile programs.
Target select sectors of the Iranian economy relevant to its proliferation activities.
Induce Iran to engage constructively, through discussions with the United States, China, France, Germany, the UK, and Russia (Department of State).[
U.S. RelationsFrance
Long standing ally of the United States.
Allowed to retain 300 nuclear warheads.
Largest net exporter of electricity in the world.
Iran
Sour relations with U.S. after unsuccessful coup, subsequent revolution in 1979.
Zero nuclear warheads; one reactor.
Engaged in ongoing talks designed to restructure their program.
Conclusion Nuclear power historically relevant, from weaponization to
modern energy generation.
Produces cheap energy, but requires tremendous investment of various resources.
Moderate efficiency; theoretically the new designs will be more efficient.
Low in carbon emissions, but may aversely affect surrounding ecosystem; uses fossil fuels for uranium mining.
No permanent waste storage facility in U.S.
Polarizing in the politics of nations- requires tremendous cooperation from world leaders.