An essence towards a quick and authentic approach regarding nuclear reactors including important ingredients like history, generations up-to-date made, a reasonable package of types of reactors, pros & cons and a touch of accidents happened in nuclear reactors.

2. Prof. DR. M. Babar Yaqoob

3. Introduction
History
How a nuclear reactor looks
Principal of nuclear fission
Generations of nuclear reactors
Classification of nuclear reactors
Pros & Cons of nuclear power reactors
Nuclear reactor accidents
Questions

4.  A nuclear reactor is a device which produces heat
energy in a controlled nuclear reaction
 It is mainly based on self sustained fission reaction
 Uranium-235 and Plutonium-239 are the most
commonly used nuclear fuel
 Heat energy released in nuclear reactions is used to
produce electricity
 Electricity is supplied to a town, to a ship or to a naval
sub-marine
 Also importantly used as a research tool
 It includes some principal parts like core, turbine,
water circuits, I&C system, cooling tower etc.

5. Serial
no.
Year Discovery and workout
1 1789 German chemist Martin Klaproth discovered Uranium
2 1930s Discovery of artificial radioactivity
3 1934 Nuclear fission was achieved by Enrico Fermi, Italian
Physicist
4 1939 Letter of death, by Albert Einstein and L.Szilard to
F.D. Roosevelt
5 1942 First nuclear reactor tested at university of chicago,
USA under Manhattan projects
6 1946 UK’s first commercial nuclear reactor in Cumberland
working at full scale anywhere in the world
7 1955 First nuclear naval sub-marine made by USA

8. Splitting of a heavy nucleus into two or
more lighter nuclei by bombarding neutron in
a chain manner. Heavy amount of energy plus
neutrons are released.

9. NUCLEAR RESEARCH
REACTORS
NUCLEAR POWER
REACTORS
80% of Research reactors are just of
two types,
 Pool-type reactors, 67 units
 Tank type reactors, 32 units
 TRIGA (training, research,
isotopes, general atomics), 38
units
 Over 770 reactors has been built
worldwide
Power reactors can be classified
 Based on coolant used
 Based on operating pressure
 Based on neutron energies
 Based on moderators
 Based on capability of fuel
production
 Based on fuel enrichment level
 Based on purpose of use

10. Types of Nuclear Reactors – Table 1
Reactor Type
Light Water Reactor (LWR)
Heavy Water Reactor (HWR)Boiling Water
Reactor
Pressurized
Water Reactor
(PWR)
Purpose electricity
electricity;
nuclear powered
ships (U.S.)
electricity; plutonium production
Coolant Type water (H2O) water heavy water (deuterium oxide, D2O)
Moderator Type water water heavy water
Fuel — Chemical
Composition
uranium-
dioxide (UO2)
uranium-dioxide uranium-dioxide or metal
Fuel – Enrichment
Level
low-enriched low-enriched natural uranium (not enriched)
Comments
steam
generated
inside the
reactor goes
directly to the
turbine
steam is
generated outside
the reactor in a
secondary heat
transfer loop
used in Canada: called “CANDU” –
“Canadian Deuterium Uranium;” Also
used in Savannah River Site reactors
(metal fuel at SRS)

11. Types of Nuclear Reactors – Table 2
Reactor Type
Graphite Moderated Reactor Fast Breeder Reactor (FBR)
Gas Cooled Water Cooled
Liquid Metal (LMFBR) (most
common type of breeder)
Purpose
electricity; plutonium
production
electricity; plutonium
production
electricity; plutonium
production
Coolant Type gas (carbon dioxide or helium) water molten, liquid sodium
Moderator Type graphite graphite not required
Fuel —
Chemical
Composition
uranium dicarbide (UC2) or
uranium metal
uranium dioxide (RBMK) or
metal (N-reactor)
plutonium dioxide and
uranium dioxide in various
arrangements
Fuel –
Enrichment
Level
slightly-enriched, natural
uranium
slightly-enriched
various mixtures of
plutonium-239 and uranium-
235
Comments
used in Britain, and France
(e.g.: AGR, MAGNOX)
used in USSR, e.g. Chernobyl
(RBMK); N-reactor at
Hanford.
breeder reactors are designed
to produce more fissile
material than they consume.
Monju; Phenix

12. The most often used nuclear power reactors are
 Boiling water reactor (BWR)
 High pressure water reactor (HPWR)
 CANDU-Pressurized heavy water reactor (PHWR)
 Advanced gas-cooled reactor (AGR)
 Liquid metal cooled fast breeder reactor (LMFBR)

15. PWR
 Higher pressure 160atm and
temperature 315C
 Uranium as a fuel
 No boiling of water
 No Radioactive contamination
 More energy with 3.2% enriched
fuel
 Compact and costly to construct
 Two water circuits
 Inspection or maintenance is easy
during operation
 Severe corrosion problems, do use
of stainless steel vessel in core
 Fuel recharging requires couple of
months
 Hardly 60 control rods are required
 Low thermodynamic efficiency
BWR
 Lower pressure 75atm and
temperature 285C
 Uranium as a fuel
 Boiling of water
 Possible radioactive contamination
in case of any accident due to single
water loop in turbine mechanism
 50% fewer valves
 80% less pipes and 50 % less pumps
 70% less cables
 Inspection or maintenance is not
possible during operation
 Strong safety precautions are needed
 370-800 fuel assemblies
 More efficiency
 Less energy with 2.4% enriched fuel

17.  Heat energy is transferred by
pressurized CO2 gas
 Graphite in core structure act
as moderator
 Core temperature reaches at
650C
 Steam is produced to drive
turbine
 No explosion due to CO2
 Noon corrosive
 Costly fuel, uranium carbide
and thorium carbide
 Complicated consolation

18.  Breeder reactor produces
more fissile material than
fuel used
 U-238 is converted into
fissionable Pu-239
 No coolant
 USA, USSR and France
have such reactors
 Long life span of fuel
 Meltdown is due in case of
Na exposure to air, water
 Na itself becomes
radioactive

19.  The most environmental friendly source of energy
 Fewer greenhouse gases are produced
 The more the electricity is produced by nuclear power, the less the use of
fossil fuel
 The less the use of fossil fuel, the less the production of greenhouse gases
 The cost of nuclear fuel is 20% of the energy generated
 Sole solution of rapidly increasing energy demand
 Best alternative to renewable sources of energy
 U-235 produces 3.7 million times as much energy as the same amount of
coal
 Worst ever killings in accidents happened
 Question mark on the highly radioactive waste
 High initial capital cost to build nuclear power house
 Limiting life span of 40-50 years
 Non-renewable energy resource of uranium
 Eutrophication

20. Three mile island reactor
no. 2 meltdown
 Occurred on March 28,1979.
 Caused release of
radioactive gases
 No injury or death was
reported
 Mechanical fault as well as
operating staff fault was the
prime cause
 A lack of trust in
government prevailed

21.  Worst ever nuclear accident
happened on April 26, 1986
 All 4 reactors got meltdown
mainly due to operating staff
fault
 400 eventual deaths
including 28 workers
 Post-disaster radioactivity
affected 200000 people
 Inherited mutation still can
be found

22.  Occurred on march 11, 2011.
 Primarily by 15 meter high
tsunami followed by
earthquake
 Power breakdown made
impossible the cooling
circuit, resulting meltdown
 Huge radioactive material
released
 No death was declared
officially
 100000 nearby people were
evacuated