What is a Hydrogen Bomb?

            Soon after the development of the atom bomb in 1945, scientists started developing a more powerful bomb. This resulted in the development of another highly destructive bomb called the hydrogen bomb. An American scientist Edward Teller and his team tested the first crude form of hydrogen bomb in 1952. It was a 10 megaton bomb, about 700 times more powerful than the atom bomb dropped in Hiroshima.

Hydrogen Bomb

            The hydrogen bomb makes use of nuclear fusion. In this process, four hydrogen nuclei combine at extremely high temperature to form one helium nucleus, producing tremendous amount of heat energy. Similar reactions take place in the sun and other stars due to which, they have been continuously producing enormous amounts of heat and light energy.

            The shell of the hydrogen bomb is made of a strong alloy. Two isotopes of hydrogen deuterium and tritium are kept inside this cover along with the atom bomb. First the atom bomb is exploded and this initiates the fusion reaction of the hydrogen bomb. The atom bomb produces a very high temperature of millions of degrees, and at this temperature, deuterium and tritium combine to form a helium nucleus, producing huge quantity of heat. This entire reaction is competed in one-millionth of a second.

            In fusion, not only are helium nuclei formed, but neutrons are also produced. These neutrons carry out fission reaction in uranium by which heat is continuously produced to help further fusion reaction. It is for this reason that hydrogen bomb is more powerful.

            Till date, hydrogen bombs have bee developed by USA, Russia (former USSR), UK, France, China, India and possibly Pakistan.

What is Nuclear Reactor?

            Fission, in physics, is the process of splitting of heavy atomic nucleons into two or more fragments. A team of scientist in Chicago, USA, led by the famous physicist Enrico Fermi, was the first to successfully demonstrate controlled nuclear fission. Under his direction, the so-called atomic pile or reactor was established in 1942 to release nuclear energy in a controlled manner.

Nuclear Reactor

            Do you know what nuclear reactors are? The nuclei of uranium are used as the main fuel to induce the split that release a large amount of heat energy. Nuclear reactors are the key unit’s nuclear power stations in which nuclear energy are produced in a controlled manner where fission takes place.

            Broadly, there are three types of reactors thermal, fast-breeder and fusion.

            In thermal reactors, controlled emission of neutrons to the core, by using moderators such as carbon or graphite increases the efficiency of fission process. They surround the neutron absorbing rods in the reactor made out of boron to release heat energy.

            Fast-breeding reactors have no moderators. In these cases, neutrons bring about fission and a mixture of plutonium and uranium oxide is used as fuel. While in operation, uranium is converted into plutonium. The plutonium is extracted and reused later as fuel. It is called fast-breeder because it produces more plutonium than it consumes. Fast-breeder reactors can extract about 60 times the amount of energy extracted from uranium in the thermal reactors.

            Fusion reactors are not yet in commercial production. Instead of splitting heavy atoms, they force very light atoms together.

            In all types of nuclear reactors, there is a coolant system in which ordinary water or gas like carbon dioxide is used. The heat produced in the reactors turns the water into steam that drives the generators to produce electricity.

            The greatest advantage of nuclear energy is that it producers a large amount of useful energy form a very small amount of fuel. It does not produce gases contributing to the ‘greenhouse effect’. The disadvantage is that the radioactive nuclear waste produced is harmful to human beings and is difficult to store. There is always a risk of accident, which can be dangerous.