power for the future
using the concept of fusion occurring in the sun to generate energy, scientist
hope to harness this energy release in the new generation of nuclear plant: The
fusion reactor. Scientists have invented two methods of making plasma hot enough
to fuse, which are: magnetic confinement reactor and inertial confinement
Figure 1: Diagram of a magnetic confinement
Gaseous hydrogen fuel turns
into plasma (a hot, electrically charged gas) with
the aid of a very high heat and pressure. Magnetic confinement
reactor squeezes the plasma in the “donut-shaped” chamber (tokamak) by using a
magnetic field. One of a type of magnetic confinement was
created in France and is known as International Thermonuclear Experimental
Figure 2: Illustration
of magnetic confinement reactor (tokamak)
At the beginning, air and
impurities are removed from the vacuum chamber. A magnet system would confine
and control the plasma. Then, the magnetic system is being charged up and the
gaseous fuel is being brought in. The gas would be broken down electrically by
the electric current that run through the vessel and become ionized to form a
plasma. The plasma particles would be energized and collide with each other. At
the same time, they would also begin to heat up. The heating method lead the
plasma to the fusion temperatures (150 – 300 million °C). The natural
electromagnetic repulsion is overcome by the particles which have been
energized. This causes the particles to fuse and release a great amount of
2) Inertial Confinement
Figure 3: Diagram of a inertial confinement
confinement reactor uses pulses form superpowered lasers to heat the surface of
a pellet of fuel, imploding it, briefly making the fuel hot and dense enough to
fuse. For example, one of the most powerful laser on Earth, is used for fusion
experiments at National Ignition Facility (NIF) in the US.
Figure 4: Illustration of inertial confinement reactor
At the beginning,
the internal piece of the hohlraum is being heated by the laser rays which
would form a surrounding plasma envelope. A blow off of plasma envelope is created
by the laser beam from the hohlraum, compressing the inter-fuel portion of the
capsule. The fuel center achieves 100 times the density of lead and set off at
100,000,000°c at the final of the implotion. In the compressed fuel, thermonuclear burn is spreaded rapidly and obtain many times
the input energy.
Figure 5: Flow chart of the mechanism of
inertial confinement fusion
These nuclear fusion experiments are just experiments and scientists
are still developing this technology. Right now, although nuclear fusion can be
achieved, it cost more energy to do this experiment than the energy produce in
fusion. This teachnology still require a long time before it is commercially
viable, and there might also be a possibility that this teachnology will never
If nuclear fusion is succesful, it will be very efficient that a single glass
of sea water can be used to produce as much energy as burning a barrel of oil,
without any waste being produced. This is because fusion reactors would use
hydrogen or helium as fuel, and sea water is sloaded with hydrogen. However,
not any hydrogen can be used. Specific isotopes with extra neutrons, called deuterium
and tritium, are needed for the reaction.
Figure 6: Illustration of Hydrogen, deuterium
stable and can be found in abundance in sea water. However, tritium is might
only be twenty kilogram could be found in the world. Therefore, another fusion
body for deutrium is needed instead of tritium.
Helium-3, an isotope of helium, might be a great substitute. It
is also rare on Earth but it can be get from the moon. Over billions of years, the
solar wind may have built up a huge deposits of helium-3 on the moon. Instead of
making helium-3, it can be mined. The lunar dust sifted is enough to power the
entire world for thousands of years.
Figure 7: Image of lunar mining for
might think that nuclear fusion is dangerous, but it is a lot more safer than
most other power plant. A fusion reactor is not like a nuclear plant, which can
melt down catastrophically. If the confinement failed, the plasma would expand
and cool, the the reaction would stop. In short, it is not a bomb.
The release of radioactive fuel like tritium, could pose a threat to the
environment. Tritium could bond with oxygen, making radioactive water which
could be dangerous as it seeps into the environment. Fortunately, there is no
more than a few grams of tritium in use at a given time, so a leak would be
Therefore, there is nearly unlimited energy to be had, at no expenses to the
environment in something as simple as water.
Nuclear fussion for the future
As of now, Generation
III is used by numerous nuclear power plant reactors to produce power. The improvements
of generation IV reactors are in terms of their sustainability, safety, and
price. Generation IV will be a opportunity for the construction of more
sustainable nuclear reactors in the future (next 20 – 50 years).
Generation IV international forum (GIF) is a worldwide co-operation recognised for
the change of Generation IV systems. There are 6 reactors which have been determined
by GIF to be the reactors of the future which have clear preferences and
mechanical headways contrasted with reactors today. They are: gas cooled fast
reactor (GFR), lead cooled fast reactor (LFR), sodium cooled fast reactor
(SFR), molten salt reactor (MSR), supercritical water cooled reactor (SCWR),
and very high temperature reactor (VHTR).
Gas cooled fast reactor (GFR)
It is a high-temperature helium-cooled fast-spectrum reactor and it has a closed
fuel cycle. The
coolant of this reactor can be heated to higher temperatures than water.
fast reactor (LFR)
It is lead or lead-bismuth-alloy-cooled reactors operating at
high temperature and atmospheric pressure .
fast reactor (SFR)
Its reactor coolant is liquid sodium, permitting a low-pressure coolant system
and high-power-density operation with low coolant volume fraction in the core.
MSRs can be divided into two types.For the first type, the molten fluoride salt
dissolve the fissile material. For the second type, the
molten fluoride salt serves as the coolant of a coated particle fuelled.
water cooled reactor (SCWR)
It is a high temperature, high-pressure, light water reactors that operate
above the thermodynamic critical point of water (374°C, 22.1 MPa). This reactor
also have a fast-neutron or a thermal spectrum.
temperature reactor (VHTR)
It is a helium-cooled reactor, graphite-moderated and a
spectrum. Nuclear heat and electricity are delivered over a range of
temperatures between 700 and 950°C, and potentially more than 1 000°C in the
advantages for Generation IV are reducing the time require for the waste to
become unradioactive, enhancing the energy obtain for the nuclear fuel, expanding
the assortment of fuels which power the reactor, and taking into account present
nuclear waste in its operations. These enable nuclear reactors to become more
sustainable and environmentally friendly.