ROLE OF NUCLEAR ENERGY IN WAR AND TERRORISM
>HOW DOES THE A-BOMB WORK?
Why does any old bomb blow up?
It blows up because somehow it is getting heated so fast that some of its material is turning to vapor, very quickly, and the vapor wants to take up a lot more room than the original solid or liquid bomb material does. That is, some of the bomb material gets vaporized and the vapor expands very quickly and pushes everything out of its way. (This all happens in a split second.) It is the vapor pushing everything out of its way, in its desperate hurry to expand. That is the explosion. In an "ordinary" bomb, the bomb material gets heated because it is burning. This is an ordinary fire -- it just burns REALLY fast. An ordinary fire happens because of chemical reactions. In this example, the molecules in whatever is burning are rearranging themselves into new molecules that are more tightly bound together than the original ones were. (A molecule is a few atoms hooked together. In a chemical reaction the same atoms get hooked together in different ways.) When something gets rearranged into a more tightly bound configuration, energy is released. In a fire, most of that energy shows up as "heat."
In an atom bomb, the bomb material gets heated from nuclear reactions (fission or fusion or both) that release a lot of energy. Nuclear reactions are different from chemical reactions in several ways; some of the differences are:
1) Nuclear reactions happen when the MIDDLE parts of atoms rearrange themselves into new MIDDLES that are more tightly bound together than the original ones were. (The middle of an atom is called the nucleus, which is where the term "nuclear" comes from. The pieces that make up the nucleus are neutrons and protons.) On the other hand, as I mentioned above, in chemical reactions it is MOLECULES that get rearranged.
2) One nuclear reaction releases a whole lot more energy than one chemical reaction. (Millions of times as much)
3) To keep a chemical fire going all you need to do is keep the temperature high enough and make sure there is enough fuel to burn. Keeping nuclear reactions going is much harder. Partly because of this, you have to have special materials (like highly "enriched" uranium or plutonium) to make an atom bomb. These special materials are not lying around anywhere -- they have to be made using fairly complicated processes. Even if you have the materials it is difficult to make a nuclear bomb work. In a nutshell, the problem is that once the bomb starts blowing apart (which happens really fast), the nuclear reactions shut down.
Difference number two is why nuclear bombs can be so much more powerful than "ordinary" bombs. Difference number three is why only a handful of nations have made nuclear bombs.
>HOW DOES THE H-BOMB WORK?
A hydrogen bomb or thermonuclear bomb is a nuclear weapon that obtains most of its energy from the fusion of hydrogen nuclei into helium nuclei. This fusion typically involves deuterium and tritium nuclei, the heavy isotopes of hydrogen. Deuterium is a stable, naturally occurring isotope with one proton and one neutron in its nucleus, and can be extracted from normal water. Tritium is an artificial, radioactive isotope with one proton and two neutrons in its nucleus, and can be formed in nuclear reactors or, during a nuclear explosion, by the exposure of lithium nuclei to the neutrons formed in that explosion.
Since hydrogen nuclei are positively charged, they repel one another. To get these heavy hydrogen nuclei close enough together to fuse into helium nuclei, the hydrogen nuclei must be heated to fantastic temperatures. This heating is done with a fission bomb--a uranium or plutonium bomb. When the fission bomb explodes, its heat is enough to trigger the hydrogen bomb.
A hydrogen bomb uses the heat from a fission bomb (a uranium or plutonium bomb, sometimes called an atomic bomb) to cause hydrogen nuclei to collide and fuse, thereby releasing enormous amounts of energy. While a fission bomb can initiate its nuclear reactions at room temperature, fusion reactions won't begin until the nuclei involved have been heated to enormous temperatures. That's because the nuclei are all positively charged and repel one another strongly up until the moment they stick. Only at enormous temperatures (typically hundreds of millions of degrees) will the nuclei collide hard enough to stick and release their nuclear energy. A typical hydrogen bomb (also called a fusion bomb or thermonuclear bomb) uses a fission trigger to initiate fusion in a mixture of deuterium and tritium, the heavy isotopes of hydrogen. These neutron-rich isotopes fuse much more easily than normal hydrogen. Because deuterium and tritium are both gases, and because tritium is unstable and gradually decays into the light isotope of helium, some hydrogen bombs form the tritium during the explosion by exposing lithium nuclei to neutrons from the fission trigger. Thus the "fuel" for many thermonuclear bombs is actually lithium deuteride, which becomes a mixture of tritium and deuterium during the explosion and then becomes various helium nuclei through fusion. The H-bomb (hydrogen, thermonuclear, or fusion bomb) derives most of its energy from the fusion or coalescence of small nuclei.
>WHERE HAS THE HYDROGEN BOMB BEEN USED?
The first thermonuclear bomb was exploded in 1952 at Enewetak by the United States, the second in 1953 by Russia (then the USSR). Great Britain, France, and China have also exploded thermonuclear bombs, and these five nations comprise the so-called nuclear club—nations that have the capability to produce nuclear weapons and admit to maintaining an inventory of them. The three smaller Soviet successor states that inherited nuclear arsenals (Ukraine, Kazakhstan, and Belarus) relinquished all nuclear warheads, which have been removed to Russia. Several other nations either have tested thermonuclear devices or claim to have the capability to produce them, but officially state that they do not maintain a stockpile of such weapons; among these are India, Israel, and Pakistan. South Africa's apartheid regime built six nuclear bombs but dismantled them later.
>WHERE HAS THE ATOMIC BOMB BEEN USED?
The first atomic bomb was produced at the Los Alamos, N.Mex., laboratory and successfully tested on July 16, 1945. This was the culmination of a large U.S. army program that was part of the Manhattan Project, led by Dr. Robert Oppenheimer. It began in 1940, two years after the German scientists Otto Hahn and Fritz Strassman discovered nuclear fission. On Aug. 6, 1945, an atomic bomb was dropped on Hiroshima with an estimated equivalent explosive force of 12,500 tons of TNT, followed three days later by a second, more powerful, bomb on Nagasaki. Both bombs caused widespread death, injury, and destruction, and there is still considerable debate about the need to have used them.
Atomic bombs were subsequently developed by the USSR (1949; now Russia), Great Britain (1952), France (1960), and China (1964). A number of other nations, particularly India, Pakistan, and Israel, are believed to have atomic bombs or the capability to produce them readily.
>HOW ARE NUCLEAR BOMBS CURRENTLY LINKED TO TERRORISM?
Nuclear bombs are today not used that frequently due to effects of the radiation. Nuclear bombs are used for wars and between countries but very seldom!
>COMBATING NUCLEAR TERRORISM
As concerns over terrorist threats mount, nuclear security and safety experts are urging stronger measures on the global front to prevent nuclear or radioactive material from falling into the wrong hands, or nuclear facilities from becoming targets. It is important to examine the threat of nuclear terrorism involving non-state actors within the context of the overall threat posed by nuclear weapons in the arsenals of states – the traditional nuclear powers, the newly emerging nuclear powers, and the threshold states. Disarmament is essential.
The rule of law and the international apparatus of multilateral legal agreements must be upheld.
BIBLIOGRAPHY
~ How Things Work
http://howthingswork.virginia.edu/nuclear_weapons.html
~ Ask a Scientist or Engineer
http://www.nsf.gov/nstw_questions/chem/quest009.htm
~ Infoplease
http://www.infoplease.com/
~ Project Ploughsharers
http://www.ploughshares.ca/content/MONITOR/monj02g1.html
~ The Evolution of Nuclear Strategy (2d ed. 1989).
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