This powerpoint presentation explains the various causes and effects of the deadly nuclear accidents across the globe

1. ACCIDENTS IN NUCLEAR POWER
PLANTS
By
GOTTMYERS MELWYN J
UR13ME064

2. TOPICS
What is Nuclear Energy?
What are its advantages?
The factors affecting the commissioning of
power plants
Accidents

3. Nuclear Energy
Nuclear power is the use of nuclear reactions that
release nuclear energy to generate heat, which most
frequently is then used in steam turbines to produce
electricity in a nuclear power plant.
Mostly Nuclear energy is generated by nuclear fission and
nuclear fusion process.

4. Advantages of Nuclear Energy
Less Pollution.
It is not dependent on natural resources
Less fuel is required.
Continuous energy generation.

5. The Fuss around nuclear power plants
Is Nuclear energy really the future source of energy??
There are a lot of accidents occurring in nuclear
power plants??
Are the modern power plants built with safety
precautions??

6. Nuclear accidents-A Glance
• There has been a total of 111 accidents in nuclear reactors so far.
• 1st accident- CRL, Ontario, Canada in 1952
• The famous Three mile Island Nuclear reactor accident took place in
1979
• Two thirds of these mishaps occurred in the US.
• Globally, there have been at least 99 (civilian and military) recorded
nuclear power plant accidents from 1952 to 2009
• This means nearly 12 accidents have occurred over the past six
years.

7. 9%
43%
11%
11%
5%
17%
4%
Accidents
CANADA
USA
UK, India
FRANCE
GERMANY, Russia
JAPAN
others

8. The Major accidents in Nuclear Power Plants
• The Fukushima Daiichi nuclear disaster
(2011)
•Chernobyl disaster (1986)
•Three Mile Island accident (1979)
•The SL-1 accident (1961).

9. Accidents before the first Major Accident
• Six accidents took place
• Two accidents in Canada, U.S and U.K.
ACCIDENTS IN CANADA
• CRL, Ontario, Canada at 3:07 p.m. Friday, December 12, 1952
• A hydrogen explosion occurred in the reactor core due to a cascade of
malfunctions and operator errors.
2nd Accident in Canada
• CRL, Ontario, Canada May 24, 1958.
• A fuel rod caught fire and broke when removed, then dispersed
fission products and alpha-emitting particles in the reactor building.

10. Accidents in United States
• Idaho Falls, Idaho, US on November 29, 1955.
• Power excursion with partial core meltdown at National
Reactor Testing Station's EBR-1Experimental Breeder Reactor I
• Cost: 5 mn US$
2nd Accident
• Simi Valley, California, USA on July 26, 1959.
• Partial core meltdown at Santa Susana Field
Laboratory’s Sodium Reactor Experiment
• Cost:32 mn US$

11. Nuclear Reactor

12. Accidents in United Kingdom
• Two accidents took place in Windscale, UK in the year 1957
• 1st Accident : Windscale, UK 1957
• CAUSE: Radioactivity release contaminated about 800 farms
• Introduced Strontium 90 to domestic milk supply.
• Milk was sold to the public without any warnings.
• Strontium 90 causes bone cancer.

13. Windscale UK 1957
• The worst nuclear accident in Great Britain's
history.
• CAUSE: Fire ignites plutonium piles,
contaminating surrounding dairy farms.
• The fire took place in Unit 1 of the two-pile
Windscale facility
• Fuel rods: Uranium
• Core: Graphite

14. • Wigner Energy: Found by Eugene Wigner
• Fire in Channel 2053 which eventually spread.
EFFECTS
1. The fire burned for three days
2. Radioactive contamination that spread across the UK and Europe
3. Incident caused 240 additional cancer cases
4. Radiations Emitted: Iodine 131, Caesium-137, Xenon-133
• INES Rating: 5

15. INESRating
•International Nuclear Event
Scale
•Scale of 1-7
• introduced in 1990
• International Atomic Energy
Agency (IAEA)

16. The SL-1 accident
• Idaho Falls, Idaho, US on January 3, 1961.
• Explosion at National Reactor Testing Station's SL-1 Stationary Low-
Power Reactor Number One
• Cause : The improper withdrawal of the central control rod,
responsible for absorbing neutrons in the reactor core.
• The accident occurred during a maintenance period.
• In four milliseconds, the heat generated resulted in an enormous
power surge.
• The resulting power surge caused the reactor power to reach
20,000MW in about .01 seconds

17. • This caused water surrounding the core to begin to explosively
vaporize.
• This extreme form of water hammer propelled control rods,
shield plugs, and the entire reactor vessel upwards.
Effects :
Immediate death of three persons
Cost : 22 mn US$
About 1,100 curies of fission products were released into the
atmosphere.

18. ThreeMileIslandaccident
• Middletown, Pennsylvania, US March 28, 1979
• reactor number 2 of Three Mile Island Nuclear Generating
Station (TMI-2).
• Cause: when the operators tried to fix a blockage in one of the
eight condensate polishers
• The accident began with failures in the non-nuclear secondary system
• This was followed by a stuck-open pilot-operated relief valve in the
primary system

19. • The water escaped through a stuck valve.
• High pressure built up in the steam generators
• The loss of heat removal from the primary loop and the failure of the
auxiliary system to activate caused the primary loop pressure to
increase
• EFFECTS
1. Release of radioactive gases and radioactive iodine into the
atmosphere.
2. A spike in infant mortality in the downwind communities two years
after the accident.
3. Anecdotal evidence also records effects on the region's wildlife.

20. The Fukushima Daiichi nuclear disaster
• Fukushima, Japan 11 Mar 2011
• The world's second INES 7 accident
• Cause: A magnitude 9.0 earthquake and associated tsunami triggered
cooling problems at Fukushima 1 & 2 stations with several reactors
• It is estimated that the hot zirconium fuel cladding-water reaction in
reactors 1-3 produced 800 to 1000 kilograms of hydrogen gas each.
• Hydrogen explosions caused structural damage
• Loss of coolant results in meltdowns in three units

21. • Some immediate injuries resulted
• 117 workers received committed effective doses above
100 mSv
• 6 workers received doses above the emergency dose limit of
250 mSv.
• the eventual number of cancer deaths, that will be caused by
the accident is expected to be around 130-640 people in the
years and decades ahead
EFFECTS

22. Material Windscale Three Mile
Island(compared to
Windscale)
Chernobyl Fukushima Daiichi
Iodine-131 740 much less 1,760,000 130,000
Caesium-137 22 much less 79,500 35,000
Xenon-133 12,000 6,500,000 17,000,000
Xenon-135 25 × Windscale
Strontium-90 much less 80,000
Plutonium 6,100
Radioactive releases compared (TBq)

23. Safety in Modern Power plants.
•Auto-shut down capabilities
•Highly Equipped & Skilled Labour
•Careful Operation
•High-quality design & construction

24. Thank You