Transcript Nuclear Hazards - SNS Courseware

Radioactive pollution is a special type of physical pollution
which is related to all major life
supporting systems like air, water and soil.
• Radioactive (nuclear) pollution is a special form of physical
pollution related to all major life- supporting systems –
air,water and soil.
• Radioactivity is the phenomenon of emission of energy from
radioactive isotopes (i.e., unstable isotopes), such as Carbon14, Uranium- 235, Uranium- 238, Uranium- 239, Radium- 226,
etc.
• The emission of energy from radioactive substances in the
environment is often called as 'Radioactive Pollution'.
• Generally radiation hazards in envt. Comes from UV rays,
cosmic rays, visible,microwave radiation.
• Among these X rays which produce out 95% of radiation
exposure.
• Nuclear energy(power plants) is used to produce electricity .But
fuel used in power plants is radioactive,which is very dangerous
& waste matrls are hazardous.
• Here the nuclear waste matrls also emit radiation. (ie) Radio
active pollution.
• Generally ,the radiation exposure is measured by the unit called
roentgen (R).
• One Roentgen is defined as the quantity of radiation which
produces 1.6 × 1012 pairs of ions in 1 gm of air.
1.Natural resources :
1) Cosmic rays from outer space. The quantity depends on
altitude and latitude; it is more at higher latitudes and high
altitudes.
2) Emissions from radioactive materials from the Earth's
crust.
2.Man-made sources :
Nuclear power plants.
X-rays.
Nuclear bombs.
Nuclear accidents.
Mining and processing of radioactive ores.
Use of radioactive materials in nuclear weapons.
• The biological effects of nuclear radiation can be divided into
three groups
(i) Short term recoverable effects(small effect which leads
to loss of hair)
(ii) long term irrecoverable effects and
(iii) genetic effect
• Internal bleeding & blood vessel damage may show up as red
spots on the skin.
• Cancer is considered to be major health problem from radiation
exposure.
• Radiation can cause changes in DNA which is known as
MUTATION.
• Acute exposures appears as burns & radiation
sickness(nausea,hair loss, weakness …)
Radiation Effects
• 0-50R
• 50-200R
• 200-450R
• 450-600R
• 600R
No visible effects
Brief periods of nausea on day
of exposure. 50% may
experience radiation sickness
(nausea and vomiting), 5% may
require medical attention, no
deaths are expected.
Most members of the group
will require medical attention
because of serious radiation
sickness. 50% deaths within
two to four weeks.
Serious radiation sickness in
all members of the group,
medical attention required.
Death to more than 50% within
one to three weeks.Over
Severe radiation sickness.
100% deaths in two weeks
• Leakages from nuclear reactors, careless handling, transport
and use of radioactive fuels, fission products and radioactive
isotopes have to be totally stopped;
• Safety measures should be enforced strictly;
• Waste disposal must be careful, efficient and effective;
• There should be regular monitoring and quantitative analysis
through frequent sampling in the risk areas;
• Preventive measures should be followed so that background
radiation levels do not exceed the permissible limits;
• Appropriate steps should be taken against occupational
exposure; and Safety measures should be strengthened against
nuclear accidents.
1) High Level Wast es (HLW): High level wastes have a very highradioactivity per unit volume. Since these wastes are too
dangerous to be released anywhere in the biosphere, therefore,
they must be contained either by converting them into inert solids
(ceramics) and then buried deep into earth or are stored in deep
salt mines.
2) Medium level wast es (MLW): Medium level wastes
(e.g., filters, reactor components, etc.,) are solidified and are
mixed with concrete in steel drums before being buried in deep
mines or below the sea bed in concrete chambers.
3) Low liquid wast es (LLW): Low liquid wastes (e.g.,
solids or liquids contaminated with traces of radioactivity) are
disposed of in steel drums in concrete- lined trenches in
designated sites.
• Monitoring radioactivity around the disposal sites.
• Prevention of erosion of radioactive waste disposal sites.
• Prevention of any drilling activity in and around the waste
disposal site.
• Periodic and long- term monitoring of such disposal sites and
areas of naturally occurring uranium rich rocks.