nuclear power lecture given to undergraduates for summer program at TINT 8 April 2010 Bangkok, Thailand

1. Nuclear Power:
a Global Look
Roppon Picha
Thailand Institute of Nuclear Technology

2. Nuclear power is currently our most potent
energy source.
& a clean energy solution for today and
tomorrow.

3. Basic human needs:
Food,
air,
water,
energy

4. How much energy?

5. The Earth is approximately 4.5 billion years old. (from
radiometric dating of mineral samples.)
2,000 years ago, there are 10 million people.
1,000 years later: 300 millions
Today: 6.7 billions.

6. (data: United Nations, U.S. Census Bureau)

7. (OECD/IEA World Energy Outlook 2004)

9. Nuclear energy is due to two important discoveries: neutron by
James Chadwick in 1932 and uranium in 1789 by Martin
Heinrich Klaproth.

10. Fission reaction
235
n+ U → X + Y + n’s

11. Fission
In 1939, Hahn, Strassmann, Meitner, and Frisch discovered
that neutron can split uranium.
92 → 56
Fission coined.
Energy release 200 MeV per reaction.

12. Fission
∼ 70 years after it was discovered, nuclear fission is now
responsible for 1/6 the total energy produced around the world.
Mochovce power plant, Slovakia

13. First nuclear reactor
In 1942, Enrico Fermi and his
team built the World’s first
nuclear fission reactor in a
squash court of University of
Chicago.
The atomic pile was called
Chicago Pile No. 1.
Enrico Fermi
(1901–1954)

14. The first man-made self-sustaining chain reactions went on for
28 minutes on 2 Dec 1942 (3:25–3:53 p.m.).

15. The pile consisted of uranium
pellets as fuel, and graphite
blocks as moderator.
Cadmium coated rods were
used to absorb extra neutrons,
dampening the reaction.

16. Chicago Pile 1
The energy of the atom’s nucleus was first unleashed.

17. Fuel choices
U-235 is fissile
Fermi: U-238 is fertile → breed Pu-239 (fissile) at fast n
energies → EBR-I (Experimental Breeder Reactor-I)
U-233 is also fissile. Can be bred from Th-232.

18. First four nuclear bulbs (@ EBR-I, Idaho Falls, USA, Dec 1951)
USS Nautilus: first nuclear submarine (1953)

19. Research: generate neutrons from fission. Low power level
(1–10 MW). Neutron flux is in the order of 1013 n/cm2 /s.
Research reactor at TINT, in Bangkok, Thailand

20. Power: generate electricity from kinetic energy of fission
fragments
Power reactor in Leibstadt, Switzerland

21. The world needs electricity for development.

22. Only 2% of African rural
people have access to
national power grid.

23. 1.6 billion people are without access to
electricity
(24.4%)
(IEA, World Energy Outlook 2006)

25. Carbon Mitigation Initiative
Collaboration between Princeton University, BP, and Ford Motor
Company
Mission: To find solutions to the greenhouse gas problem.

26. CMI’s 4 strategies
1. Increase the energy efficiency of our cars, homes, and
power plants while lowering our consumption by adjusting our
thermostats and driving fewer miles.

27. CMI’s 4 strategies
2. Capture the carbon emitted by power plants and store it
underground.

28. CMI’s 4 strategies
3. Halt deforestation and
soil degradation worldwide,
while reforesting more
areas.
1
CO2 +H2 O → C6 H12 O6 +O2
6
(photosynthesis)

29. CMI’s 4 strategies
4. Produce more energy from nuclear and renewable
fuelssolar, wind, hydroelectric, and bio-fuels.
Bellville NPP, France [ c Areva]

30. Coming Clean: The Truth and Future of Coal in the Asia-Pacific (World Wild
Fund for Nature)

32. “Estimated radiation doses ingested
by people living near the coal plants were
equal to or higher than doses for people
living around the nuclear facilities.”
Hvistendahl, M. (2007). Coal Ash Is More Radioactive than Nuclear
Waste. Retrieved October 14, 2009, from Scientific American Web site:
http://www.scientificamerican.com/article.cfm?id=coal-ash-is-more-
radioactive-than-nuclear-waste
McBride, J. P. et al. (1978). Radiological Impact of Airborne Effluents of
Coal and Nuclear Plants. Science, 202(4372), 1045–1050.
ash = bottom ash + fly ash
fly ash (U, Th) → escapes to environment

33. Asia:
countries operating NPP’s under construction
Pakistan 2 1
China 11 21
India 18 5
S. Korea 20 6
Japan 54 1
(data: IAEA, Feb 2010)

34. Japan: 54
That’s third most in the world.

35. Korea
Seoul during Korean War (1950)
At the end of WWII (1945), power generation capacity in Korea:
North 88.5%, South 11.5%. Korean War (1950–1953) put
Korea in total destruction.

36. (eryoni@flickr)
First nuclear power in South Korea: 20 July 1978 (Kori-1
reactor). Today (Mar 2010) nuclear electricity is almost 40% of
total.

37. Uranium
Uranium is one of the most abundant elements found in the
Earth’s crust. It can be found almost everywhere in soil and
rock, in rivers and oceans.

38. 235U
is the only natural isotope which is fissionable by thermal
neutrons.

39. World’s largest high-graded uranium deposit: McArthur River, Canada.
World’s known uranium is estimated to be about 5.5 Mt (source: OECD NEA
& IAEA, Uranium 2007: Resources, Production, and Demand)

40. Another important source of fuel is the nuclear weapon
stockpiles in the USA and countries of the former Soviet
Russia. These weapons contain highly enriched uranium.
Future reprocessing technology will further increase uranium
usage efficiency.

41. Uranium deposits
(Uranium 2005: Resources, Production and Demand, OECD/IAEA)

43. Uranium
Samples from drilling during
uranium exploration
( c : Cameco)

44. Yellowcake
Yellowcake is the uranium compound mostly consisting of
triuranium octaoxide (U3 O8 ), and some uranium dioxide (UO2 )
and uranium trioxide (UO3 ).

45. n + U → U∗

46. Neutron cross section

47. Uranium enrichment
Only 0.7% of natural uranium is 235 U, the fissile isotope. Higher
concentration (of around 3–5%) is required in a nuclear reactor.
There are mainly two enrichment processes, both using UF6 .
1. gaseous diffusion
2. gas centrifuge
under development: laser enrichment
(photoexcitation of isotopes)

48. Fuel and spent fuel
Level of enrichment of reactor fuel
is much less than that of nuclear
weapon (over 85% enriched).
They serve different purposes.
Highly enriched uranium billet
(US DoE)

49. Fuel pellets
UF6 is typically converted back to UO2 solid, compressed into
pellets.

50. Fuel
A typical pellet of uranium weighs about 7 grams. It can
generate energy equivalent to 3.5 barrels of oil, 480 m3 of
natural gas, or 800 kg of coal.

51. Fuel
The uranium is encased in ceramic. The fissile isotopes must
be densely packed so that the chain reaction can sustain itself.

52. Fuel pellets are packed inside zirconium tubes (resistant to
radiation, heat, and corrosion). The rods are bundled together
into an assembly.

53. For most reactors, high energy neutrons are moderated by
water.

54. Capture, Excitation, Deformation

55. U-235 mass split:
heavy/light ∼ 1.4

57. where does the Energy come from?

58. Kinetic energy of fission fragments heat up the water.

59. Conversion reactors
Converters or conversion reactors are designed to convert
material that is not fissionable (but “fertile”) with thermal
neutrons to one that is.
23 min
238
U+n → 239
U −−→
−− 239
Np + β − + ν
¯
2.3 d
239
Np − −
−→ 239
Pu + β − + ν
¯
22min
232
Th + n → 233
Th − −
−→ 233
Pa + β − + ν
¯
27 d
233
Pa − →
− 233
U + β− + ν
¯

60. Fast breeder reactors

61. Current reactors
Most power reactors use
normal water as moderator
and coolant.
(Nuclear Engineering International
Handbook 2007)

63. Control room
Reactor operators must go through intensive certification
process.

64. Operators must be trained and
licensed:
• reactor theory
• thermodynamics
• plant components
• design and operation
• emergency response
Each reactor type (PWR, BWR,
and others) has a different
training program.

65. Interactions
Ranked by characteristic length: γ ∼ n > e− > hcp
Characteristic energy deposition of hcp: Bragg’s peak
Coulomb forces lead to continuous excitation and ionization of
medium. Neutrons and gamma can penetrate far due to lack of
electric charge.

66. Shielding
Penetration of radiation depends on its stopping power (specific
energy loss).
dE
S=−
dx
For charged particles, S increases as velocity decreases.
Bragg curve.

67. Shielding
Even in air, the energetic alphas can travel for only several cm.
R (cm) = 0.56E (MeV) for E < 4 MeV
R (cm) = 1.24E − 2.62 (MeV) for 4 < E < 8 MeV
For medium of mass number A,
R (mg/cm2 ) = 0.56A1/3 Rair
(Cember, H., Introduction to Health Physics, McGraw-Hill, 1996)

68. α’s and β’s are easy to protect against.
Just paper or plastic is fine.

69. Shielding
The concerns of radiation are mostly related to highly
penetrating radiation such as gamma rays and neutrons.
Gamma rays are electromagnetic wave. Its interaction strength
depends on the charge number (Z ) of the material.
Neutrons are neutral. Must be slowed down via direct collisions.

70. Shielding
High-Z materials can be used to effectively shield γ-rays. Main
interactions are
• Photoelectric absorption
• Compton scattering
• Pair production

71. Absorption coefficient in Pb
H. A. Enge Introduction to nuclear physics (1966)

72. High-Z materials are good for shielding γ-rays.

73. Neutrons cross sections are very energy dependent.
Hydrogen-rich medium can be used to slow down neutrons.
Then thermal neutrons can be absorbed by materials with high
neutron capture cross section such as boron or cadmium.

74. Storage pool in an interim
storage facility at Oskarshamn,
Sweden
(Image: SKB; Photographer:
Curt-Robert Lindqvist)

75. Vitrification into borosilicate glass (mixture of SiO2 and B2 O3 ) is
used to contain high-level waste from nuclear reactors.
Pictured is the amount of high-level waste due to nuclear
electricity generation in one person’s lifetime.

76. A knife can cut, can decorate, can kill.
Fire can cook, can warm, can burn.

77. First X-ray image (1895)
Frau Roentgen’s hand

78. Any use for radioactive stuff from the nuclear reactor?

79. Reactor isotopes
• iodine-131 (t1/2 = 8.0 d) and iodine-132 (t1/2 = 2.3 h): thyroid
cancer treatment and diagnosis
• iridium-192 (74 d): internal radiotherapy, gamma radiography
• molybdenum-99 (66 h): used as source of technetium-99m (6 h)
• cobalt-60 (5.3 y): external radiotherapy, industrial radiography
• dysprosium-165 (2 h): treatment of arthritis
Radiotherapy @ Cancer Hospital, Kostanai, Kazakhstan ( c Samuel C. Blackman)

80. How do people respond to nuclear for therapy?

81. Waterford, Ireland (2006)

82. Mini break
Who discovered
the proton?

83. Operating reactors
(IAEA, Feb 2010)

84. ∼ 76% of electricity in France comes from nuclear (year
2008, IAEA)

85. 56 new reactors are being constructed (Feb 2010).

86. Advanced designs
Generation 3+ reactors are being built around the world. They
have simpler designs, are more fuel efficient, produce less
waste, and have enhanced safety.
Some of these are:
• Advanced Boiling Water Reactor (ABWR), by General
Electrics (GE) Nuclear Energy (approved May 1997)
• System 80+, by Westinghouse (May 1997). Not actively
marketed.
• AP600, by Westinghouse (Dec 1999) and AP1000, by
Westinghouse (Dec 2005)
• EPR, by Areva NP

87. EPR
Olkiluoto 3: First Gen-3+ reactor built

88. PBMR
PBMR fuel pebbles

89. PBMR
PBMR uses He coolant and graphite moderator.

91. Fusion
From n + 235 U to D + T .

92. Fusion
More difficult due to Coulomb repulsion. High temperature
environment is required.
exercise: Estimate potential energy between two hydrogen
nuclei at distance 10 fm apart.

93. Fusion
D+T →α+n
Q = 17.6 MeV: α (3.5) + n (14.1)
other reactions (much lower cross sections):
D + D → 3 He + n (Q = 3.3 MeV)
→ T +H (4.0 MeV)
D +3 He → 4 He + H (18.3 MeV)

94. Various power sources are used to spark the gas and
discharge it into plasma. Must know how to control plasmas
long enough for fusion to break even.
Plasma discharge in ASDEX tokamak (Germany)

95. Magnetically confined plasma:
National Spherical Torus Experiment (NSTX) in Princeton

96. NSTX: Princeton Plasma
Physics Lab, Oak Ridge Lab,
Columbia U., U. of Washington
at Seattle
D+D fusion
First plasma: 12 Feb 1999

97. ITER: Gas heated to over 100 million K. Plasma density ∼ 1020 m−3 . 500
MW of fusion power (non-electricity).

98. ITER: Future tokamak
Location: Cadarache, France
Expecting first plasma by 2016

99. Conceptual fusion power plant (EFDA)

100. International collaborations
GNEP: Global Nuclear Energy Partnership

101. International collaborations

102. International collaborations

103. For countries without a nuclear power plant, the
first step is the hardest step. People must have
strong determination and responsibilities.
Once an NPP is built, the country will develop
more. Everybody starts from zero.

104. Thanks.