Nuclear Power – An Energy Analysis

http://nuclearinfo.net

Nuclear Power – An Energy Analysis

Martin SeviorAssociate ProfessorSchool of PhysicsUniversity of Melbourne



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 “away” from itself. Life requires large amounts of Energy.


Life and energy Life takes energy from the sun


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 the products it needs. (Food, Metals, Plastics, Water)


Energy in Australia

Australia’s Electricity needs are currently supplied by 44 GigaWatts of power stations.

This is forecast to grow by over 2% per year to around 60 GigaWatts by 2020

On average 1.5 GigaWatts increase each year

Equivalent to Loy-Yang Power Station


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 2040’s Effect will be to triple world energy consumption. Only a large scale trade embargo will prevent

them from effectively competing with the west.


World Energy Growth.Energy Growth by

sourceEnergy Growth by “region”

Projections are “business as usual”

Source: U.S. Energy Information Administration.


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


Global Climate Change The Earth’s 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


CO2 increase in the Atmosphere


Global Climate Change

The current CO2 concentration is unprecedented over half a million years

The different curves are different predictions based on different physical assumptions and future CO2 emissions

Predicted world temperature changesPast world temperature changes


Predictions for CO2 outputsThe 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


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 my generation.


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 it’s reliance on Coal-powered electricity, has the highest


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.


Nuclear Energy Chemical reactions release a few electron-

volts of energy per reaction.

Nuclear Fission releases 240 Million electron volts per reactionA 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.


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?


Uranium Abundance. The Earth’s 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?


How long could Nuclear Power last? How much energy does it take to build a

Nuclear Power plant? How much energy does it take to create

Uranium fuel? How much energy does a Nuclear Power

plant produce over it’s lifetime? This should be greater than the energy cost.


The Nuclear Fuel cycle.


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


Environmental Product DescriptionThe overall goals of an EPD is, "through

communication of verifiable and accurate information, that is not misleading, on environmental aspects of products and services, to encourage the demand for and supply of those products and services that cause less stress on the environment, thereby stimulating the potential for market-driven continuous environmental improvement".

Independently Audited


Vattenfall’s EPD for Nuclear Power Normalized for 1 GW Nuclear Power Plant.

(NPP) operating for 40 years Energy cost of Constructing the NPP Energy cost of Mining and Milling U Energy cost of enriching Energy cost of dismantling the NPP Energy cost of disposing the wasteUnits PetaJoules (PJ) = 1015 Joules. 1 GigaWatt year = 31.5 PJ


System BoundariesIn any Life Cycle Analysis there are

boundaries.


NPP Construction Typical Construction tree.

Total energy cost for Construction and Decommissioning NPP:

4 PJ


Mining and Milling Vattenfall utilize Uranium from Olympic

Dam, Rossing and Navoi, Uzbekistan Over 40-year life of NPP total energy cost

of mining the Uranium.

5.5 PJ


Conversion and Enrichment The “Yellow Cake” from the mines must be

converted to UF6 , Neglecting U usage

2 PJ Then enriched to 3% 235U. Vattenfall uses a

mixture of Gaseous Diffusion and Centrifuge Neglecting U used for enrichment this becomes

0.5 PJ


Operations Need to fabricate the Fuel rods

1.2 PJ Energy used to operate the plant and

consumed in ongoing Maintenance

1.1 PJ


Waste Disposal Sweden has a mature multibarrier waste

disposal plan.

Energy cost for 100,000 year isolation

4.3 PJ


Total Energy Cost Total Energy cost over 40 years (neglecting

additional U) 18.6 PJ Energy Generated (85% efficiency) 1054

PJ Energy Gain of 56 Repaid in 8 months of operation.


CO2 emissions from NuclearVattenfall EPD calculations


Vattenfall CO2 emissions from other sources


Storm van Leeuwen and Smith This website has been widely quoted They find the Energy cost of building a

NPP to be 82 PJ Assume Decommission cost to be 82 PJ Assume Waste disposal cost to be 82 PJ Predict Mining and Milling cost to be

YCE 654

GigaJoules per TonneY = Yield

C = % U3O8YC

E 275

or


Additional Assumptions No new rich deposits of Uranium will be

discovered. An extrapolation of their formula implies no net

energy gain at Ore concentrations of 0.02% and below.(Rossing works at 0.03%)

They conclude we will rapidly deplete the exploitable Uranium reserves with thermal reactors


Testing Storm and Smith How well do Storm and Smith reproduce

currently operating Uranium mines?Ranger: Ore 0.25%: Predict 5.1 PJ/year, Report 0.8 PJ/yearOlympic Dam: Ore 0.05%Predict 60 PJ/year, Report 5 PJ/yearRossing: Ore 0.035%Predict 69 PJ/year, Report 1 PJ/yearThese 3 mines provide 35% of current world

production


Cross Checks 60 PJ is two Giga-Watt years of electricity Cost of supplying this via Diesel is over 1

Billion dollars At $40 Kg U Rossing only earns $100

Million per year Entire energy consumption of Namibia is

only 50 PJ


Consequences… Even with current mining technology we’re

far from exhausting our recoverable Uranium.

We’ve mined less than 1 ten millionth of all the Uranium in the Earth’s crust.

Rossing provides 465 PJ of energy per year at an energy cost of 1 PJ

What can we estimate for the future?


Uranium AbundanceCurrent discovered, proven reserves 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.)


Nuclear Power is sustainable The current Uranium price is nowhere near

high enough to sustain the energy costs predicted by Storm and Smith

There will be no lack of Uranium for thousands of years.

The motivation for 4th generation reactors is really to reduce the amount of waste.

Nuclear Power – An Energy Analysis

Documents

Transcript of Nuclear Power – An Energy Analysis