Page 59 - IACC Newsletter October November 2013 Issue 13

Basic HTML Version

From the Indo-US nuclear deal to Kudankulam: A synopsis on nuclear energy
Despite nuclear energy making up a significant portion of recent national and international news, there is much confusion
about even its basics. Here's what you need to know about it.
Nuclear energy has been in the news a lot in recent years, from Iran’s alleged nuclear weapons programme, India’s
agreements with the United States, the International Atomic Energy Agency (IAEA), and the Nuclear Suppliers Group
(NSG), Fukushima, and at home, Kudankulam. Yet there is much fear, confusion, and ignorance about even the basics of
nuclear energy or weapons. Here is a very quick primer on how 8,500 crores of your money is being spent.
1.
What is nuclear energy?
All power plants other than solar essentially turn turbines to generate mechanical energy, which can then be converted
into electricity. Hydroelectric power uses the kinetic energy of falling and/or running water, wind power uses air currents,
and fossil fuels generate steam upon burning, which turns the turbines. Nuclear energy uses the energy released by the
fission of an actinide, usually uranium (but plutonium and thorium are also considered nuclear fuels), to turn water into
steam which would in turn rotate the turbines to produce mechanical energy and eventually electricity.
2.
How does a nuclear power plant work?
This depends on the type of reactor design, but essentially, the nuclear fuel is bombarded by a stream of neutrons. As the
heavy uranium atom splits, it releases energy and more neutrons. This starts a chain reaction as the new neutrons split
more fuel atoms. In a nuclear weapon, designers maximize the number of fissions by using very pure uranium and other
techniques, but in a nuclear reactor, the idea is to control the chain reaction and sustain it. To that end, engineers use
moderators and neutron poisons to control the number of fissions that occur. Also, the fuel used is a fraction of the purity
required to make weapons. However, reactors used for propulsion, such as on submarines and aircraft carriers, use much
higher concentrations of fuel. This helps to miniaturize the reactor as more energy is generated per unit mass of fuel.
In some reactors, the heat from the energy released by fission is carried away from the reactor core by a coolant and used
to generate steam; in other reactor designs, the core heats the water directly. Both these methods have their advantages
and disadvantages, but the principles remain the same in all reactors.
3.
Why is everyone talking about nuclear energy as the future?
In the era of climate change, scientists are worried about the footprint humans leave on the planet’s ecosystem. Species
go extinct, water is contaminated, air polluted, fish become scarcer, and the population inches ever upwards. Though
there are still many questions regarding the causes of climate change, the impact of pollution on our lives is clear to see.
Nuclear power offers abundant energy without the corresponding carbon emissions fossil fuels emit.
Power engineers divide electricity supply into two main components – base load and peak load; the former refers to the
minimum amount of energy consumed at any point by an area and the latter refers to the maximum. Obviously, these
needs fluctuate depending upon time of day and region – for instance, industrial areas use more power than residential
zones. Nuclear power is the most reliable substitute for fossil fuels to provide steady power in large quantities throughout
the day. While other sources can augment nuclear power, they have their inherent limitations such as the sun and wind.
Another important quality of nuclear power is the energy density of uranium, which is about two million times higher than
coal. Even after adjusting for fuel enrichment, efficiency, and conversion loss, one kilogram of uranium yields the same
amount of energy as 20 tons of coal. This makes uranium ideal for transportation. In addition, given the fraction of the
total cost of a nuclear power plant the fuel represents, even sharp fluctuations will leave electricity prices relatively
unaffected.