Nuclear energy1
description
Transcript of Nuclear energy1
Nuclear energy is the energy stored in the nucleus of an atom and released through fission, fusion and radioactivity
There are two types of nuclear energy
1. Nuclear Fission2. Nuclear Fusion
NUCLEAR FISSION
When a particle of sufficient energy is shot on to a heavier nucleus the nucleus splits and releases energy. This reaction is called NUCLEAR FISSION
When Uranium 235 nucleus is bombarded with
a neutron
0n1 + 92U235
56Ba141+36Kr92+30n1+energy
Fission of U235
When an Uranium nucleus undergoes fission, neutrons are released. These neutrons in turn split the surrounding uranium nuclei releasing neutrons in each reaction. This is called CHAIN REACTION
CHAIN REACTION
Controlled fission reaction
Example for nuclear fission
ATOM BOMB
On Aug 6 1945 a Uranium bomb was dropped on the city of Hiroshima killing 1.5 lakhs of people. Here is the picture of that bomb. Length: Approx. 3 meters (120 inches) Weight: Approx. 4 tons (9,000 lbs) Diameter: Approx. 0.7 meters (28 inches) Element: Uranium 235
Another bomb was dropped at Nagasaki on Aug 9 killing thousands of people. Here is the picture of that bomb. Length: Approx. 3.2 meters (128 inches) Weight: Approx. 4.5 tons (10,000 pounds) Diameter: Approx. 1.5 meters (60 inches) Element: Plutonium 239
A device that is used to produce nuclear energy by controlled fission reaction is called nuclear reactors
There two types of nuclear reactors
• Pressurized Water Reactor• Boiling Water Reactor
Pressurized Water Reactor
Boiling Water Reactor
In India Pressurized Water Reactors are used.
Mentioned below are some reactors present in India
First nuclear reactor in Asia – Apsara
Tarapur India’s First nuclear Power Station
Rawatbhata India’s first commercial nuclear reactor
Kalpakkam Mini Reactor
Narora Atomic Power Station
Advanced Heavy Water Reactor
Parts Common to all reactors
• REACTOR CORE – Part of the reactor where fuel is kept
• FUELS – Commonly used fuels are Uranium (233,235), Plutonium(239)
• SOURCE OF NEUTRONS – Mixture of polonium and beryllium powder
• MODERATORS – Materials used to slow down neutronse.g. – Heavy Water (D2O), Graphite
• CONTROL RODS – Used to control the no: of neutrons in the reactorse.g. – Boron, Cadmium
• SHIELD TO PROTECT RADIATION – protect living organism from harmful rays like gamma, some shields made of thick lead and concrete are used around the core and the reactor
• COOLANTS – To reduce the heat generated as part of reaction, some fluids like high pressure water liquids, metals and gases take heat out of the core
NUCLEAR FUSION
The process of merging two or more light nuclei to form a heavier nucleus is called NUCLEAR FUSION
Deuterium is a hydrogen isotope with mass number 2.At very high temperature Deuterium nuclei with high kinetic energy fuse to form Helium nucleus
Example for nuclear fusion
Energy liberated from sun, stars etc
Figures are given below
Galaxy
Energy Liberated from Sun