Following the disasters in Three Mile Island (1979) and
Chernobyl (1986), nuclear power has been on the top of environmentalists’
villains list. Also on the list are the absence of cyclist lane, littering, and
NASCAR probably. However, the same people who compiled the list in the first
place are currently faced with the dilemma that nuclear can in fact be the
savior to postpone an already scheduled event where everyone is invited called Destruction of Planet Earth by Greenhouse Gases;
environmentalists keep on receiving emails filled with suggestions to change
the name of the event, but they refuse to give respond.
Nuclear power produces zero greenhouse gas, making it an
excellent pollution-free alternative to the predominant fossil fuels. Based on
rough calculation, a pound of uranium – from which nuclear power is generated –
can produce the same amount of energy as 1 million gallons of gasoline or 3
million pounds of coal; apparently environmentalists also understand that rough
calculation is more preferable than an actual math.
The process of generating electricity always creates
byproducts or at least environmental impacts. Even hydropower potentially
introduces negative effects to natural habitats by altering flow of river; solar
panel also produces toxic chemicals during its construction and at the end of
its life. Since nuclear power plant does not create greenhouse gas as byproduct,
there must be something else. Unfortunately, this something else is radioactive
waste such as iridium-192, cobalt-60, cesium-137, and others things with
uninteresting names. Many of them can trigger birth defects and cause cancer.
There is also a chance that a person exposed to radioactive waste will
transform into mutants, maybe with useless superpowers if they’re lucky enough.
Nuclear power is therefore at the same time full of good promises and sinister
smiles. It is basically just like Lex Luthor.
A nuclear power facility may stretch to dozens of square
miles, but the witchcraft happens on subatomic levels – these are the levels
where no one can see or observe without assistance from flying brooms and some
pointy hats. Such facility is built for one sole purpose: generating
electricity from nuclear fission – a chemical reaction where a single atom splits
into two smaller nuclei.
The fuel used in nuclear power plants is enriched uranium
oxide comprised of uranium-238 (96% - 97%) and uranium-235 (3% - 4%). The
latter is the main fissile (capable of undergoing and sustaining nuclear
fission chain reaction) isotope of uranium. Natural uranium contains much less
amount U-235 so enrichment is required for more effective energy production. The
enrichment process and methods will not be discussed here in details due to health
and safety reasons; potential use of many advanced scientific terms can be
overly abusive to the brains and may cause serious headache.
While Uranium is the heaviest natural element, it is also
one of the easiest to break apart. When free neutron bumps into a U-235 atom, the
neutron will get absorbed and render the entire atom unstable. At the tipping
point of its unstable state, the atom splits into two smaller atoms. This
fission reaction generates more free neutrons which will run into many other
U-235 atoms and repeat the process to infinity. Every time an atom splits, a
small portion of its original mass becomes heat or energy. Water that separates fuel tubes absorb the heat and turns into steam. Then, the steam drives a turbine which generates electricity. As a result, the
self-sustaining energy creation process generates massive amount of electricity
to power your light bulbs, computer, microwave, TVs, and those weird-shaped
electric massagers.
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| One of the main purposes of nuclear power is to create gigantic mushroom out of smoke just few miles away from a beach |
Of course a nuclear power plant houses a myriad of equipment worth millions of dollars to control the fission reaction. Simply putting uranium rods next to each other will not trigger any kind of energy-production cycle. In case you have the opportunity wander inside a nuclear facility – there is a near zero chance of it happening – you will probably bump into the nuclear reactor which contains the fuel and fission control instruments.
The fuels are comprised of around 150 (if not more) bundles
of 12-foot long rods; each bundle has more than 200 individual rods made from
pellets of uranium oxide. These rods are immersed in a coolant and contained
inside pressure vessel. Fission reactions are controlled by the amount of neutrons
used. In addition to uranium rods, a reactor also houses control rods made from
neutron-absorbing element for example cadmium.
Due to the nature of the fission where there are always more
neutrons than required following every atom-split occurrence - hence chain
reaction - the energy-production process can go berserk. Fission also increases
in speed over time and leads to uncontrolled reaction if left without some sort
of interference. By inserting some control rods into the bundle, large amount
of neutrons are absorbed to prevent runaway reaction. To increase the speed of
fission reaction again, control rods can be partially or entirely lifted out
from fuel rods.
Radioactive waste, as byproduct of nuclear fission, must be treated
in the instance it is produced. This is why the reactor is housed in a concrete
liner inside a pressure vessel built within a disaster-proof concrete building.
Imagine a shiny steel safe where people who don’t trust the bank keep their
money; because they also don’t trust the safe either, they put another safe
inside it. For some reasons, these people are convinced that even two layers of
security measures are not enough, so they buy a bigger safe to house the two
smaller ones. Then they purchase a piece of land and build a safe house for the
sole purpose of keeping money. Because it is unbelievably safe, they allow some
of their richest friends to keep money for a fee. In short, they build their
own bank when they don’t trust the bank.
Extra precautionary measures are critical to make sure that
the nuclear fission inside the reactor is always in secure safe controlled
conditions. Three Mile Island and Chernobyl disasters gave examples of what can
happen if either the facility or human resource operating the facility is
incapable. On the other hand, properly harnessed nuclear power accompanied by suitable
radioactive waste treatment can potentially release us from the addiction to
fossil fuels.