NUCLEAR ENERGY 2 - Jan Leen Kloosterman · NUCLEAR ENERGY 2.0 500 times more energy 1000 times less waste Dr Jan Leen Kloosterman ... 1950 1960 1970 1980 1990 2000 Year TWh TWh=TeraWattHour=1012

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1Reactor Institute Delft / Nuclear Energy Science&Technology

NUCLEAR ENERGY 2.0

500 times more energy

1000 times less waste

Dr Jan Leen KloostermanAssoc. Prof Nuclear Reactor Physics

Head of Section Physics of Nuclear ReactorsProgram Director of Sustainable Energy Technology


Reactor Institute DelftResearch on Energy and Health with Radiation

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Neutrons

Spin-Echo Small Angle Neutron Scattering (SESANS)

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Positrons

POSH-Strongest positron beam in the world


Energy• solar cells• batteries• hydrogen storage• nuclear reactors

} Materials research

Current Research Themes (1)

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Health• radiation and radioactive nuclides for therapy• “ and “ for diagnostics• radiation detection systems for imaging• new production routes for radionuclides

Current Research Themes (2)


Simeon de pilaarheilige, Simeon Stylites, Carel Willink, 1939

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010001800192719601974198719992030

= 1 million people

Source: www.pbs.org/wgbh/nova

World population


World population

year

popu

lati

on /

mill

ion

9 billion

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Last 160,000 years (from ice cores)and the next 100 years

Time (thousands of years)160 120 80 40 Now

–10

0

10

100

200

300

400

500

600

700

CO2 in 2100(with business as usual)

Double pre-industrial CO2

Lowest possible CO2stabilisation level by 2100

CO2 now

Temperature

difference

from now °C

CO2

conc

entr

atio

n (p

pm)

Source: IPCC

CO2 concentration


Electricity consumption in the Netherlands

0

20

40

60

80

100

120

1950 1960 1970 1980 1990 2000

Year

TWh800 Watt/capitaTWh=TeraWattHour=1012 Whr

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Renewable Energy, Sep 27, 2011

442 reactors (Jan 2011)

62 under construction

157 planned

322 proposed


Physics of Nuclear Energy

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Elements, atoms and more…

Electrons

Protons

Neutrons

Atoms


Uranium

• Uranium contains 92 protons• Uranium is the heaviest element on earth• Uranium is almost twice as heavy as lead (19 g/cm3)

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Atom: cloud of electrons around a nucleus• the nucleus consists of Z protons and N neutrons

• Z is the “atomic number”, determines the chemical element (always an integer)

• A = N+Z is the number of nucleons in the nucleus;also called the “atomic weight”

• the neutral atom has Z electrons surrounding apositively charged nucleus

10-10 m

10-14 mAtoms


Uranium isotopes

Not fissile

Fissile Good fuel

99,3% 0,7%

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Exercise: Lifetime of the Earth

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8

9

Nuclide a Yield %

U-234 2.446 10 0.005

U-235 7.038 10 0.720

U-238 4.468 10 99.275

Calculate the lifetime of the earth (or more precise:

the lifetime of the material the earth is made of )

T

½


Solution: Lifetime of the earth

0 01/2

55 50

8 8 80

5 80 0

8 5

For both U-235 and U-238 holds:

ln 2exp exp

exp 0.7200.0072526

99.275exp

Assume (equal amounts of U-235 and U-238 formed)

ln 0.0072526

From this you

N t N t N tT

tN T N

N T N t

N N

T

9can calculate 6 10 a (6 billion years)T

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Decay of Uranium

40 MeV+


How to extract energy from decay of Uranium?

Geothermal energy: 40 MeV per nuclide

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How to extract energy from fission of Uranium?

• Uranium is so heavy that the nucleii decay of fission in two products. Especially U-235 is instable.

• Fission is easier if uranium is hit by a bullet. Neutrons are very good bullets. Why?


235 200 MeVX YU n n

Nuclear fission

Radio-active

24 2 2CH 2O 2 8C eVHO O

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Fission product yields

80 100 120 140 16010

-3

10-2

10-1

100

101

102

M as s num ber A

Yie

ld (

%)

LW R

U-235

P u-239P u-241 I-131

Cs-137Sr-90


Distribution of energy

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Gasoline Coal

2500 liter 3000 kg

Fossils equivalent to 1 gram of U235


Binding energy per nucleon

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aE

236U: Ea=5.3 MeV239U: Ea=5.5 MeV

Coulomb barrier for fission


Adding a neutron (easily enters the nucleus) releases

Eb(236U)- Eb(235U)=6.6 MeVEb(239U)- Eb(238U)=5.1 MeV

• All odd heavy nuclides fission easily (thermal neutrons)• All even heavy nuclides need energy threshold in MeV range• Most important nuclides:

233U, 235U, 238U, 232Th, 239Pu, 240Pu, 241Pu

Inducing fission

Fissile Fissionable

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10-2

100

102

104

106

10-1

100

101

102

103

104

Fis

sion

cro

ss s

ectio

n

f (ba

rn)

Energy (eV)

U-233

U-235Pu-239

U-238

Fissile

Fissionable

Fissile/fissionable nuclides


Fission cross section

10-2

100

102

104

106

10-1

100

101

102

103

104

Fis

sion

cro

ss s

ectio

n (b

arn)

E nergy (eV )10

-210

010

210

410

610

-8

10-7

10-6

Fis

sion

spe

ctru

m

U -235

P u-239

U-238

Moderation

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Number of collisions needed

Collisions for scattering from 2 MeV to 1 eV:

Element A

H 1 15

D 2 20

C 12 92

Na 23 176

U 238 1731

n


Enrichment

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Fuel composition

99,3% 0,7%

U-238 U-235

Natural uranium

4% enriched uranium in nuclear fuel

4%96%


1.004q

• Developed during the Manhatten project at the Oak Ridge National Laboratory (ORNL) in the US

• Diffusion of Uranium Hexafluoride (UF6) through a semipermeable membrane under high pressure

• Separation factor per step quite small:

Uranium enrichment: Gas diffusion

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Gas diffusion cascades


• Developed in the Netherlands by Kistemaker c.s.• Parallel development in Germany and UK• Establishment of the Uranium Enrichment Company

URENCO at 5 March 1970• UF6 separation in a rotating centrifuge• Energy consumption factor 10 smaller compared to

gas diffusion processes• Separation factor depending on design

1.10q

Uranium enrichment: Ultracentrifuges

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Centrifuge cascades


Exercise: Uranium consumption KCB

• Natural uranium contains 0.7% U-235

• KCB needs 9 tonnes of enriched uranium annually (4.7% U-235)

• The tails have enrichment of 0.2% U-235

• Calculate the annual feed of natural uranium

50,000 – 70,000 rpm

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Mass balance for Uranium gives

Mass balance for U-235 gives

4.7 0.29 81

0.7 0.2

F p T

p T p T

F F

p T

F T

F P T

Fx Px Tx

Px Tx Px F P xF

x x

x xF P P P tonnes

x x

Product

Feed

Tails

Answer: Uranium consumption KCB


Fuel pellets

Contain 4% Uranium-235 and 96% Uranium-238.

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Fuel construction and inspection


Positioning of control rods, preparing for transportation

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FissionFissionCaptureLeakage

Scattering

Neutron balance


September 17, 2012 46

Moderator

U-238

U-239

Pu-239

Np-239

U-235

Moderator

U-238 Pu-239

U-235

neutron

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Multiplication factor, k

# neutrons in generation n+1

# neutrons in generation nk

• k=1: critical, stationary situation, stable• k>1: supercritical, increasing population, unstable• k<1: subcritical, decreasing population, ‘unstable’


U-238 capture cross section

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Doppler feedback mechanism

Due to the vibration of the nucleus, the effective resonance broadens.

The area remains virtually constant.


September 17, 2012 50

U-235

Moderator

U-235

U-239

Np-239

U-238

Moderator feedback

Doppler feedback

1) Stable system (important for control)

2) Loss of cooling shuts down the reactor

3) Loss of moderator shuts down the reactor

Feedback mechanisms

Documents

NUCLEAR ENERGY 2 - Jan Leen Kloosterman · NUCLEAR ENERGY 2.0 500 times more energy 1000 times less waste Dr Jan Leen Kloosterman ... 1950 1960 1970 1980 1990 2000 Year TWh TWh=TeraWattHour=1012