Nuclear Energy

of a nuclear power reactor. A typical 1,000 megawatt reactor contains 50,000 fuel rods – about one
hundred tons of uranium.
� Nuclear Reactor: The nuclear reactor is where the nuclear fuel is fissioned and the resulting
chain reactions are controlled and sustained at a steady rate. We discuss this in more detail in Part
III below.
� Decommissioning and Dismantling:
Nuclear power plants were originally designed with an operating life of 30 years. However,
nowadays, the nuclear industry believes that it can safely operate nuclear plants for around 40 to 60
years. When the reactor completes its working life, it is dismantled. Unlike conventional coal and
gas power plants, the dismantling of a nuclear power plant is a very long-term, complicated and
costly operation, because the entire nuclear power plant has become contaminated, all of its parts
including the concrete reactor building have become radioactive. The long-term management and
clean up of these closed reactors is known as “decommissioning”. It involves managing and
cleaning up the highly radioactive fuel, residues, massive quantities of radioactive equipment and
components, mixed hazardous wastes and the mountain of contaminated concrete and debris
(making up the reactor building) that have now accumulated at the plant site.
Only a very small number of nuclear power plants have so far been completely dismantled.
Generally, the most common decommissioning method is that the intensely radioactive products,
especially the deadly cobalt 60 and iron 55 formed inside the reactor vessel from neutron
bombardment, are first allowed to decay considerably. During this period, which can be anywhere
from 5 to 100 years, depending upon the decommissioning plan, these huge, intensely radioactive
mausoleums must be guarded and protected from damage or unwarranted intrusion. After this, the
actual process of dismantling begins. The reactor is now cut apart into small pieces either by
humans or by remote control, and the still-radioactive pieces packed into containers for
transportation and final disposal at some “low-level” nuclear waste disposal site. xlix
� Disposal of cooling water: The water that cools the reactor core becomes heavily contaminated
with tritium, or radioactive hydrogen, and with carbon-14. Despite this, it is discharged into nearby
water bodies, like seas or rivers.
Disposal of radioactive nuclear fuel waste:
Every year, one-third of the nuclear fuel rods must be removed from the reactor, because
they are so contaminated with fission products that they hinder the efficiency of electricity
production. The uranium fuel after being subjected to the fission reaction in the reactor core
becomes one billion times more radioactive. l A person standing near a single spent fuel rod can
acquire a lethal dose within seconds. This spent nuclear fuel is going to be intensely radioactive for
tens of thousands of years, therefore it needs to be safely stored for centuries to come.
But it is also thermally extremely hot when removed from the reactor. Therefore, the spent
fuel is first stored for many years in on-site storage ponds and continually cooled by air or water. If
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