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NUCLEAR ENERGY

Welcome to my nuclear energy power point presentation. Its purpose is to give you a flavour of what nuclear energy is all about. I hope you find it informative and enjoyable.

Charles Hobson BSc(hons), BA

G0MDK 2NUCLEAR ENERGY

1. Fission: Splitting the atom Usually uranium

2. Fusion: Fusing 2 light atoms to form a new atom

3. Radio active isotope decay: Plutonium 238

Fission fuel: Uranium isotope U-235.

Fusion fuel: Hydrogen isotopes - Deuterium and Tritium

Processes 1 & 2 yield huge amounts of energy (heat) Fission is chain reacting; Fusion is not.

Process 3 yields useful heat from radioactive decay

Nuclear energy can be derived from three different processes:

G0MDK 3FISSION

1. Slow moving neutron enters U 235

2. U 235 absorbs neutron and becomes highly unstable U236

3. U 236 splits into radio active strontium 90 & Caesium 137

4. Released neutrons absorbed by more U 235 and the process repeats. (Chain reaction)

5. A huge amount of energy (heat) is released

Combined mass of Sr 90 & Cs 143 less than U 235

Loss of mass is energy

E = mc2

G0MDK 4FUSION

The resulting Helium will have less mass than the combined masses of the hydrogen isotopes: Deuterium and Tritium.

The lost mass is the huge amount of released energy (heat) E = mc2

2035: Estimated date for 1st Nuclear Fusion Power Plant

Fusion involves two hydrogen isotopes fusing together at extremely high temperature.

The result is Helium, protons and huge amounts of energy.

Red balls Neutrons; Yellow Protons

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NUCLEAR REACTOR POWER STATION

Turbine generators produce ~ 1000MW of electrical power

The condenser may receive and discharge its cooling water from either nearby large bodies of water or large cooling towers. (lower right side of above animated picture)

Containment bldg is a 1.0m thick re-enforced concrete structure

Reactor vessel 4mx3m 300 tons 9” thick tough carbon steel

Reactor produces 3500MW heat

G0MDK 6URANIUM

• It is number 92 in periodic table 92 electrons

• It’s nucleus has 92 protons and from 141 to 146 neutrons

• This means that uranium has 6 isotopes U233 up to U238.

• Uranium is found naturally as U238 with ~ 0.72% U235

• U235 is the only naturally occurring fissionable isotope

• U-238 is enriched to ~3% U-235 for Nuclear Power Plants

NOTES:

1. There is enough known economically accessible U238 ore to keep all of the world’s nuclear power plants running for 200 years.

Uranium is a silvery white metalic element

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REACTOR FUEL RODS

• FUEL Ceramic Uranium Oxide UO2 (Melting point 2800OC) Enriched Uranium (3-5%) pellets 1cm dia. x 1.5cm long.

• Pellets are inserted in 3.7m long zirconium alloy tube.

• 264 fuel rods are braced together to form a fuel assembly. 193 fuel assemblies make up the reactor core. Note: The quantities cited above are for a typical reactor core.

• CONTROL RODS: Silver Indium Cadmium alloy pellets.

•Pure U-238 density is ~ 20gcm-3 Lead is (8.9gcm-3)

•The density of Uranium oxide is ~ 10gcm-3

•Doing some math the weight of reactor core = 10,000kg or 10 metric tonnes.

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URANIUM ENRICHMENT

Enrichment (Increase % of U-235) is a complicated process. There is no chemical difference between Uranium isotopes

U-235 and U-238 can only be distinguished by their mass difference (~1.3%) A chemical process is first used to convert the Uranium to Uranium Hexa fluoride (UF6), which has the property of being a solid at room temperature and a gas above ~ 640C

A heated Gas centrifuge separates out the U-235.

G0MDK 9WORLD-WIDE NUCLEAR POWER (2009)

Country & no. of

reactors

Total Electric Pwr. Cap. MW

Nuclear Power % Shared

Canada (18) 12,679 14.8

France (58) 63,236 75.2

Germany (17) 20,339 26.1

Japan (55) 47,348 28.9

S. Korea (21) 18,716 31.1

Russia (32) 23,084 17.8

Ukraine (15) 13,168 48.6

UK (8) 10,962 17.9

US (104) 101,229 20.2

World (442) 378,910 16.0

All 31 Countries not shown

G0MDK 10UK ELECTRICAL POWER

UK 2009 Electricity Source

kWH (billion)

Percent of total

* US % of total

Gas 371 44% 22%

Coal 165 28% 49%

Nuclear 69 18% 20%

Renewable (Bio) 11.5 3%

Wind 9.3 2.5%

Hydro 5.2 1.3% 6%

Imported France 2.8 <1%

UK 2009 Electricity consumption 5% lower than in 2008

Nuclear power 25% greater than 2008

UK gas imports: 32% 2007, 50% 2009, est. 75% 2015

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BRITAIN NUCLEAR POWER PLANTS

Combined capacity ~ 9GW

7 Advanced Gas Cooled Reactors (AGR)

1 Pressurized Water Reactor (PWR) Sizewell B

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UK SIZEWELL B NUCLEAR POWER STATION

Built and commissioned between 1987 and 1995

Built on time to budget £2,030 million

Connected & synchronised to National Grid 14 February 1995

G0MDK 13SIZEWELL B NUCLEAR POWER STATION

Third loop condenses steam out of turbine using sea water

Generators (2) produce 1200MW of power (2 million homes)

Station runs continuously 18 month cycle

1 month shut down for standard maintenance and refuelling

Pressurized Water Reactor (Only one in UK)

Primary water loop heated by reactor to 3200C 155 BAR (2240psi)

Heat exchanger to secondary loop 62 BAR steam (92psi)

High pressure steam drives turbine which turns generator

G0MDK 14NUCLEAR POWER IN OCEAN GOING

VESSELS

8 Nuclear Subs were lost, 2 US, 4 Soviet and 2 Russian

USS Thresher 1963 and USS Scorpion 1968.

Reactors very compact, smaller than normal Nuclear Power Stations.

Requires highly enriched Uranium (20%)

Fuel lasts for years.

Reactors heat water for steam turbines

Turbine propels vessels. * China and France propel ships with electric motors, (turbines drive electric generators

There are over 200 nuclear powered submarines and surface ships worldwide

G0MDK 15NUCLEAR POWER IN SPACE

Outer solar system and deep space environment very hostile

Space probe equipment needs to be kept warm and electrically powered

Sunlight brightness decreases at the inverse square of distance from the Sun.

Planet Distance from Sun Light available

Earth 150 million km 100%

Mars 228 million km 43.0%

Jupiter 779 million km 3.70%

Saturn 1.43 billion km 1.10%

Uranus 4.5 billion km 0.11%

Neptune

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NUCLEAR POWER IN SPACE

a. Radio-isotope Thermoelectric Generators (RTGs) b. Nuclear Reactors (NRs)

a. US flew 47 RTGs and 1 NR b. USSR flew 35 NRs and 2 RTGs)

SNAP (System for Nuclear Auxiliary Power)

Nuclear power sources flown in space

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NUCLEAR POWER SPACE

Cutaway view 12cm dia. 14cm high Wt = 2.1kg

4.8” x 5.6”

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NUCLEAR POWER SPACE

Two 40kg RTGs on each LES

Designed for 125We 26V (Actual 154We)

2004 still providing electrical power.

Contributed to success of subsequent Voyager one and two missions

Lincoln Experimental Satellites LES-8/9 Launched 1976. To provide pwr for 5 yr

G0MDK 19TWIN VOYAGERS 1 & 2

Voyager 1 status: 17.4 billion km from sun. 2011-02-04

Voyager 2 status: 14.2 billion km from sun. 2011-02-04

33 years after launch both space craft still sending data

Voyager 1 &2 launch Dates Sept. 1977 and Aug.1977

Mission to explore all giant planets and their moons

Carry on into outer space.

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US HISTORY OF FUSION1970- Chairman of US AEC predicted Fusion Power Plants would be on line by 1995

1976- US EDRC produced plan to achieve this

1980- President Carter signed into law the Magnetic Fusion Energy Engineering Act (October 1980) that articulated that goal and mandated the funding to achieve it. We were on our way!

$600 million per year, was authorize, and a clear goal of a working model Fusion Power Plant by 1990.

1981- Carter was not re-elected. Funding was slashed to $150 million per year by new administration, which essentially scuttled the US program for Fusion Energy.

G0MDK 21FUSION IN EUROPE

As of 2010 Joint European Torus (JET) located at Culham Science Centre Oxfordshire, has been the largest magnetic confinement of plasma physics study.

• 1997 JET produced 16.1 MW (21,600 hp for 0.5 seconds.

• International Thermonuclear Experimental Reactor ITER

• International Research and engineering project Expected to demonstrate 500MW fusion power output with 50MW power input. Not done (before)

• Being built in Cadarache, France. Seven Nations involved: US, Russia, China, EU, S. Korea, India, Japan

• EU as host will contribute 45% of cost & rest 9% each.

Fusion experiments:

G0MDK 22MAGNETIC FUSION

(The Tokamak)Inside 100 tonne vacuum vessel

Toroid weight 384 tonnes

Wt. of iron core 2800 tonnes

Positive ions (stripped deuterium and tritium atoms) injected

Lorenz forces cause ion plasma to circulate inside toroid

Plasma current (I2R) heats plasma. Mag. Fields compress ions

Neutrons fly off in straight line hits toroid walls

G0MDK 23FUSION In the USA

Lawrence Livermore National Laboratory, California National Ignition Facility (NIF)

• World’s largest Laser experiment

• 192 giant Laser beams at 500 trillion watts.

• Laser power focussed on tiny pellet

• Pellet contains Hydrogen isotopes

• Its temperature is raised to 100 million degrees C.

• Cost to build $3.5 billion (some political interference)

• Credits for the following NIF Video & images: “Lawrence Livermore National Laboratory.“ _Livermore, California USA

•

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National Ignition Facility Video

To see video click HERE

When video is finished, return to this slide by clicking on the left arrow on the upper left side of the web page.

Then continue on to the next power point slide

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NIF FUSION

A NIF target contains a polished capsule about two millimeters in diameter, filled with cryogenic (super-cooled) hydrogen fuel.

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NIF FUSIONHohlraum

A metallic case called a hohlraum holds the fuel capsule for NIF experiments. Target handling systems precisely position the target and freeze it to cryogenic temperatures (18 kelvins, or -427 degrees

G0MDK 27NIF FUSIONHohlraum

The hohlraum is a pencil-eraser-sized cylinder that holds the target, a spherical capsule no larger than a peppercorn.

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NIF FUSION Target Chamber

On March 10, 2009, at 3:15 a.m., a 192-beam laser shot delivered 1.1 million joules of ultraviolet light to the center of the target chamber - the first time any fusion laser has broken the megajoule barrier (a megajoule is the energy consumed by 10,000 100-watt light bulbs in one second).

G0MDK 29NIF FUSION

Target Positioner

This view from the bottom of the chamber shows the target positioner being inserted. Pulses from NIF's high-powered lasers race toward the Target Bay at the speed of light. They arrive at the center of the target chamber within a few trillionths of a second of each other, aligned to the accuracy of the diameter of a human hair.

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NUCLEAR ENERGY

Thank you for taking time to view this presentation. I would be most grateful for

your comments and suggestions.

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