Radiation Hazards Energy in the process of being transmitted, it may in different forms - PowerPoint Presentation

Slide1

Radiation Hazards

Energy in the process of being transmitted, it may in different forms as light, tiny particles, visible light, ultra-violet light, transmission signals for TV and radio

Nuclear

radiation:

Arises from hundreds of different kinds of unstable atoms, created in nuclear reactions

.

Ionizing radiation:

Emitted as unstable items

,

which can damage living tissue

Slide2

Effect of Radiation on Human body

Radiation injury

Causes changes in the

Living tissues causing radiation sickness

Somatic effects -harmful to the person

Genetic effects - reflected in the offspring

.

Slide3

Sources of Natural Radiation

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

Slide4

Source of Artificial Radiation

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.

Slide5

Types of Ionizing Radiation

Alpha Particles Radiation

Beta Particles Radiation

Gamma Rays Radiation

X-ray Radiation

Neutrons

Slide6

X-rays and gamma rays

X-rays And Gamma Rays Make Up Part Of The Electromagnetic Spectrum.

They Can Travel Forever Until They Hit An Object And Reactions Occurs:

Slide7

Penetrating Radiation

-X-Rays & Gamma Rays-

X-rays and gamma rays can penetrate the body and

Irradiate internal organs.

Exposure can result in external and internal doses.

Internal exposure can occur when rays are

ingested,Inhaled

, or absorbed through the skin

Slide8

Beta Particles

Beta particles are excess electrons.

Particles can be low or high energy emitters.

Low energy emitters can be shielded by cardboard.

High energy emitters need a more dense shielding material, such as plexiglas.

Slide9

Non-Penetrating Radiation

-Beta Particles

Can not penetrate the body to irradiate internal Organs.

Can penetrate dead outer-layer of skin and result in Damage to live skin cells.

Can cause damage to eye lenses.

Ingestion, inhalation, or absorption through the skin might result in internal exposure.

Slide10

Radiation Absorbed Dose

-RAD

RAD is a unit of measurement used to describe the

Amount of energy transferred from a source of ionizing Radiation to any material, including human tissue.

It is the quantity of radiation received by a patient.

As a unit of exposure, 1 rad means that each gram of air at 0° c and

1 atmosphere has absorbed 100 ergs of energy.

As a unit of dose, 1 rad means that each gram of exposed tissue has absorbed 100 ergs of energy.

Slide11

Radiation Equivalent Man

-REM-

Different types of ionizing radiation cause differing Degrees of biological effects even when the same level of

Energy is transferred (same number of ergs).

Rem is used to express the quantity of radiation received by radiation workers and populations.

The rate at which an individual is exposed also Influences the level of biological harm.

Dosimeter are used to measure a dose equivalent

.

Slide12

Biological Effects of radiation

Exposure above permissible levels may result in

Somatic effects

Physical effects

May be immediate or delayed

Genetic effects

Slide13

Biological Effects of radiation

Birth defects due to irradiation to reproductive

Cells before conception

Teratogenic effects

Cancer or congenital malformation due to

Radiation exposure to fetus in utero

Slide14

Biological Effects

-Threshold-

Threshold effects might occur if an individual receives

A dose above the threshold level.

Acute radiation syndrome: large whole body dose in a short time

Effects occur at 100 Rad

Slide15

Biological Effects

-Threshold-

Radiation-induced cataract formation

Acute effects occur at 200 Rad

Chronic effects occur at 800 Rad

Other thresholds

Severe skin injury occurs at 1,500 Rad

Teratogenic effects occur at 20 Rad

Slide16

Biological Effects

-Non-threshold

Chance of effect occurrence is proportional to the received dose.

Severity of effects are not necessarily related to exposure level.

Chance effects include:

Cancer - estimated to be 5 deaths per 10,000 persons, whom each

Received 1,000

mRem

Genetic effects

Slide17

General Radiation Effects

Impurity

Impurity production, that is transmutation of nuclei into other nuclei which themselves may be radioactive; this mechanism is caused by neutrons through fission

activation (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.

Slide18

General Radiation Effects

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.

Slide19

General Radiation Effects

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.

Slide20

General Radiation Effects

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.

Slide21

General Radiation Effects

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

produce

significant

quantifies of

Helium and hydrogen in beryllium, with the Result that the metal decreases in density.

Slide22

General Radiation Effects

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

.

Slide23

Response to radiation depends

on:

Total Dose

Dose Rate

Radiation Quality

Stage Of Development At The Time Of

Exposure

Slide24

Five Disaster Due To Radiation

Atomic Bombings Of Hiroshima And Nagasaki – World War II, 1945

Fukushima Disaster – March 11, 2011

Chernobyl Disaster – April 26, 1986

4-Mayak Nuclear Plant – September 29, 1957

Soviet Submarine K-431 Accident –August 10, 1985