1. Nuclear Plant Life Extension
Group no: 05
Mohd Tayyab Saeed
Vivek kumar
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Vishal Varshney

2. Content
• Nuclear Energy
• Nuclear Radiations
• Ageing of plant
• Ageing management
• Life extension
• Various plants working on extended life
• Refrences
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3. Nuclear Energy
• Energy from nucleus.
• Two methods:-
Fission
Fusion
Nuclear Fission - Occurs when neutrons
impact and split the nuclei of certain atoms.
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4. n
Fast Neutrons are
unsuitable for sustaining
further reactions
235U
n
fast
neutron n Slow neutron
fast
n
neutron
235
U
n
fast neutron
n Slow neutron
Insert a moderator to
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slow down neutrons

5. Nuclear Fission Chain Reaction
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6. Nuclear Reactors
• Nuclear Reactor - Device that permits a
controlled fission chain reaction.
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7. Radiation

β

Alpha ( ) - Moving particles composed of two neutrons
and two protons.
Stopped by layer of skin
Beta (β) - Consists of electrons.
Stopped by layer of Aluminium foil of 3mm.
Gamma () - rays CANNOT be stopped.
They can be attenuated to safe limits using thick Lead
and concrete
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8. Harmful effects of Radiations
Nuclear radiations composes gamma rays
which causes
• Cancer
• Genetic alteration
• Loss of fast growing cells such as skin cells,
intestinal lining and hair.
• Poison the Ecosystem.
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9. Reactors Worldwide
• Currently 441 nuclear power reactors in 31
countries.
– Combined capacity of 363 gigawatts.
– Provide 18% of world’s electricity.
• Currently 30 reactors under construction in
10 countries.
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10. Nuclear Power Plant Life
• Normally, Nuclear Plant get a license of 40
years.
• After taking various ageing management
plans the life of a plant can be extended
upto 60 years.
• Researches for new monitoring techniques
which may keep plant operation safely upto
80 years.
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11. What is Ageing?
• The International Atomic Energy Agency
(IAEA) defines ageing as a continuous time-
dependent loss of quality of materials, caused
by the operating conditions.
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12. Effect of ageing
• Neutrons bombard the pressure vessel
Over period of years that bombardment can
cause reaction that displace atoms in the
material
• Produce tiny voids
• Reduce the metal’s toughness and its ability
to resist cracking
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13. Major Concerns
• Embrittlement
• Cracking in the reactor pressure vessel and
its piping
• Degradation of the concrete containment
• Ageing Cables
• Corrosion in burried water pipes
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14. Plans for managing ageing
• Aim: To provide for the timely detection and
mitigation of significant ageing effects.
• Periodic inspection of pressure vessel,
concrete containment structure, main pipes
and cables.
• New monitoring techniques which are used
to detect tiny voids or cracks.
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15. New Monitoring Techniques
• Acoustic Monitoring
• Guided wave
• Phased array
• Diffused field
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16. Acoustic Monitoring
• When crack grows in metal, the rupture
releases tiny pulses of acoustic energy
• In the same way as earthquake sends out
seismic waves
• Sensors detect these waves and can
monitor a developing flaw
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17. Guided wave
• Transducer generate ultra- sonic waves
which propagate through metal pipe or the
walls of pressure vessel
• Ultrasonic waves scattered provide
indication of cracks or corrosion
• It wouldn’t require inspector to strip off
insulation to inspect pipes
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18. Phased array
• In this technique a group of transmitters
releases separate ultrasonic waves, which
interact to form one larger wave front
• By controlling the timing and amplitude of
the individual pulses,researchers can steer
the wave front to scan a structure for flaws.
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19. Diffuse field
• To monitor a coarse-grained material like
concrete, a single ultrasonic pulse is intro-
duced into the materials.
• Receiver listen for the tiny echoes produced
by the waves interactions with all the grains.
• To composite signal creates a distinct
signature for that materials,which will
change if the material degrades.
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20. Plant Life Extension
• These Engineering assessments have
established many plants to operate much
longer by managing its ageing effects.
• The life can be extended upto 60 years or
even more.
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21. Some plants under extended life
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22. References
• “IEEE Spectrum” , pg no 24-29 , Aug 2012.
• US ENERGY INFORMATION ADMINISTRATION, Annual
Energy Outlook 2001 with Projections to 2020, Rep.
DOE/EIA – 0383 (2001), US (EIA) (2000).
• UNITED STATES- NUCLEAR REGULATORY
COMMISSION, Licensing Renewal (2000) (Available at
http://www.nrc.gov/nrc/reactor/lr/index.html).
• T. OTSUKA, “Current Status of Life Management Policies
for Nuclear Power Plants Management in Japan”, IAEA
Specialists Meeting on Strategies and Policies for Nuclear
Power Plant Life Management, 28–30 September 1998.
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23. Thank You !!
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