Pollution and Highly toxic waste generated by Nuclear Reactors

[makam]

Everyday we are being greeted with the news of NSG clearance India got
from the NSG (Nuclear Supplier Group) published in all News papers.
This approval will enable India to import and obtain supplies,
technology and Investment hitherto unavailable because of the ban on
exporting them from the NSG countries. Now since the ban is lifted
India can build and operate many reactors to satisfy her power hungry
industries and agriculture.

But the there are concerns regarding the safety and waste disposal.
Agreed that nuclear power plants will be running on nuclear fuel and
the power generated thus will be much cheaper than produced by using
coal or oil. But the disadvantage is that the capital invested in a
nuclear power plant is much higher as lots of safety precautions have
to be taken for the safe operation of the plant.

Safety is utmost important in nuclear reactors as they are potential
atom bombs if not handled properly. The following two incidents will
show the worst accidents that has taken place in the world .

Three Mile Island accident. On March 28,1979 an accident took place
at the Three Mile Island Unit-2 Nuclear Power Plant which was a
commercial plant, in Pennsylvania, USA. Because of some pump failure
the turbine and reactor shut down which resulted in the pressure in
the system increased resulting in the pilot operated valve to open
instead of closing. Coolant passed out. As enough coolant was not
present the nuclear fuel overheated resulting in the Zirconium
cladding rupture and fuel started melting . ).

Chernobyl in Soviet Union is the worst nuclear accident the world has
seen till now excluding the bombing of Japanese Towns. Here the
nuclear plant accident released huge quantity of radioactive
materials in the atmosphere. The reactor was completely destroyed. Two
people have died because of the explosion in the reactor and most of
the deaths was due to radioactivity fall out. This happened on 26th
April 1986 at the number four reactor in Chernobyl plant situated near
Pripyat. The nuclear plant spewed out thick flumes of fire, smoke and
radioactive materials into the environment. The flumes have drifted
over extensive areas of Soviet Union, Europe and North America. In
Soviet Union itself a mammoth evacuation started and more than 300
hundred thousands were evacuated and settled somewhere else. All the
areas near the reactor and surrounding regions were washed and sand
scooped out and replaced and resulted in a massive cleaning operation.
The International Atomic Energy Agency (IAEA) and WHO in its report
have said that 56 people have directly died and 4000 cancer deaths.
About 600000 people were highly exposed to radioactivity.

The Reactors have to be operated in a careful and efficient manner and
all the measuring and controlling Instrument should be fail proof and
should have redundant surveillance instrument systems to check and
inspect critical areas. Proper security arrangements should be in
place to see that no sabotage could be carried out.

Waste disposal – This is the greatest problem of any nuclear
installation faces as huge quantities of nuclear waste is generated
every day, gets accumulated over years and is a very big head ache
for the planners and managers of nuclear reactor power plants. These
waste can not be used or recycled anywhere and does not have any user
value and is rather a dangerous waste and difficult to dispose off.

It is not that only nuclear installation produce nuclear waste. Oil
exploration companies in the USA have produced enormous quantities of
nuclear waste.
( about 8 million tones of waste in the last 20 years).

The majority of nuclear waste is of low intensity per mass or volume
like used protective clothing, contaminated liquids (when radioactive
materials have spilled over they are washed using chemicals and this
is stored in underground reservoirs) and others. Sometimes the
monitoring instruments will be infected and may have to be discarded
and kept in protective stores. Same is the case with the machinery,
casks which bring the fuel rods of nuclear fuels etc.

The biggest problem is the spent fuel, ie., the fuel rods which have
been used in the reactor and have to be replaced once their use was
over. Once the fuel rods are taken out of the core of the reactor they
will be highly radioactive and had to be handled safely in special
casks and normally stored in high security stores or buried in
underground chambers. Some times plutonium can be extracted from them
and these rods are taken to Fuel reprocessing Plants where they treat
these fuel rods and extract Plutonium, a man made metal, which is
highly Toxic and which can be used for making nuclear bombs and also
for the running of reactors. Plutonium along with thorium could be
used as fuel in Fast Breeder Reactors.

Fuel reprocessing plants produce more waste than the nuclear plants
and has lots of contaminants which cannot be treated and has to be
stored indefinitely as many of their half cycles are over hundreds of
years. Soil also gets contaminated if it comes in contact with
radioactive materials and has to be scraped and stored and cannot be
dumped anywhere else.

Radioactivity can be ingested, inhaled, absorbed or injected into the
human body without the person knowing it and after a few years he
could be a victim of cancer caused by radioactivity. The USA has 108
sites which are contaminated and are unusable for any kind of use.
Cleaning up these site is an uphill task and requires lot of man
power, machinery and money and is an extremely slow process.

Many minor accidents have taken place in many nuclear plants and the
operators and engineers working there have been transferred once they
have contracted 5MR (Milli roentgen) of radiation and fresh people
posted in Indian nuclear installations. Some times police or military
personnel have been brought to carry out manual works when some
untoward incidents happen.

So before a plant is constructed extreme care should be taken in the
planning stage itself in the storing and disposal of nuclear wastage.


ooooxoooo