Radiation is energy transmitted through space or matter in the form of waves or particles. It includes visible light, ultraviolet light from the sun, and radio/TV signals. Nuclear radiation comes from unstable atoms undergoing radioactive decay, emitting particles like alpha and beta or electromagnetic waves like gamma rays. Exposure to ionizing radiation can damage living tissue. Natural sources of radiation include cosmic rays, radioactive elements in the earth's crust like radon, and some food/drink. Medical procedures and occupational exposures also contribute. In materials, radiation can cause impurities from nuclear reactions, ionization by charged particles, and displacement of atoms from their normal positions in the crystal structure.

2. Muhammad Umair
Bukhari
Engr.umair.bukhari@gmail.com
http://onlinemetallurgy.com

3. What is Radiation ?
Radiation is energy in the process of being transmitted, which
may take such forms as light, or tiny particles much too small to
see. Visible light, the ultra-violet light we receive from the sun and
from sun-beds, and transmission signals for TV and radio
communications are all forms of radiation that are common in our
daily lives.
Nuclear radiation arises from hundreds of different kinds of
unstable atoms.While many exist in nature, the majority are created
in nuclear reactions.
Ionizing radiation which can damage living tissue is emitted as the
unstable atoms (radionuclides) change ('decay') spontaneously to
become different kinds of atoms.

4.  Alpha particles Radiation
 Beta particles Radiation
 Gamma rays Radiation
 X-Ray Radiation
 Neutrons

5.  Cosmic radiation
The global yearly average dose is 0.39 millisieverts
 Earth's Crust
The global yearly average is 0.46 millisieverts.
 Radon is a naturally radioactive gas that comes from
the uranium that is widespread in the earth's crust.
The global yearly average dose is 1.3 millisieverts.
 Food and Drink
The global yearly average dose of 0.23 millisieverts

6.  Medical
The global yearly average dose is 0.3 millisieverts.
 Environmental Radiation
 Nuclear and other industries
 The nuclear power industry
For the public the global yearly average dose is 0.008
millisieverts.

7. Impurity
Impurity production,that is transmutation of nuclei into
other nuclei which themselves may be radioactive; this
mechanism is caused by neutrons through fission
andactivation (capture).Impurities can also be deposited from
the creation of hydrogen or helium when a proton or an alpha
particle, respectively, becomes neutralized in the material of
passage.
Ionization
That is, the removal of electrons from atoms in the material
and the formation of ion pairs in the path of the charged
particles.Large Energy Release in a small volume, which can
result in thermal heating of the material. This may be
especially important in those cases where the material is a
radiation shield.

8. Atom Displacement
Atom Displacement from their normal position in the
structure of the material displacement atoms may leave
lattice vacancies or cause interchange of dissimilar atoms in
the lattice structure.
Displacement damage is the result of nuclear interactions,
typically scattering, which cause lattice defects. Displacement
damage is due cumulative long-term non-ionizing damage
from the ionizing radiations.

9. Metals, Alloys, and Metal-to-Metal Bonds
The principal effect of radiation on metals and
alloys is the creation of lattice vacancies and
interstitial atoms in an otherwise perfect
crystal.This results in an overall dilation that
decreases the density of the material. Neutron
irradiation produces significant quantities of
helium and hydrogen in beryllium, with the
result that the metal decreases in density.

10. INAEA
According to The International Atomic Energy Agency
(INAEA), nuclear and radiation accident/ disaster is
defined as “An event that has led to significant
consequences to people, the environment or the facility.”
Whether accidental or planned.

11. 1-Atomic Bombings of Hiroshima and Nagasaki – World War II, 1945
2-Fukushima Disaster – March 11, 2011

12. 3-Chernobyl Disaster – April 26, 1986
4-Mayak Nuclear Plant – September 29, 1957

13. 5-Soviet Submarine K-431 Accident –August 10, 1985