Milestones in the History of Nuclear Energy

• December 2, 1942: The Nuclear Age began at the University of Chicago when Enrico Fermi made a chain reaction in a pile of uranium.
• August 6, 1945: The United States dropped an atomic bomb on Hiroshima, Japan, killing over 100,000.
• August 9, 1945: The United States dropped an atomic bomb on Nagasaki, Japan, killing over 40,000.
• November 1, 1952: The first large version of the hydrogen bomb (thousands of times more powerful than the atomic bomb) was exploded by the United States for testing purposes.
• February 21, 1956: The first major nuclear power plant opened in England.

Advantages of Nuclear Energy

• The Earth has limited supplies of coal and oil. Nuclear power plants could still produce electricity after coal and oil become scarce.
• Nuclear power plants need less fuel than ones which burn fossil fuels. One ton of uranium produces more energy than is produced by several million tons of coal or several million barrels of oil.
• Coal and oil burning plants pollute the air. Well-operated nuclear power plants do not release contaminants into the environment.

Disadvantages of Nuclear Energy

The nations of the world now have more than enough nuclear bombs to kill every person on Earth. The two most powerful nations -- Russia and the United States -- have about 50,000 nuclear weapons between them. What if there were to be a nuclear war? What if terrorists got their hands on nuclear weapons? Or what if nuclear weapons were launched by accident?
• Nuclear explosions produce radiation. The nuclear radiation harms the cells of the body which can make people sick or even kill them. Illness can strike people years after their exposure to nuclear radiation.
• One possible type of reactor disaster is known as a meltdown. In such an accident, the fission reaction goes out of control, leading to a nuclear explosion and the emission of great amounts of radiation.
• In 1979, the cooling system failed at the three mile island nuclear reactor near Harrisburg, Pennsylvania. Radiation leaked, forcing tens of thousands of people to flee. The problem was solved minutes before a total meltdown would have occurred. Fortunately, there were no deaths.
• In 1986, a much worse disaster struck Russia's Chernobyl  nuclear power plant. In this incident, a large amount of radiation escaped from the reactor. Hundreds of thousands of people were exposed to the radiation. Several dozen died within a few days. In the years to come, thousands more may die of cancers induced by the radiation.
• Nuclear reactors also have waste disposal problems. Reactors produce nuclear waste products which emit dangerous radiation. Because they could kill people who touch them, they cannot be thrown away like ordinary garbage. Currently, many nuclear wastes are stored in special cooling pools at the nuclear reactors.
• The United States plans to move its nuclear waste to a remote underground dump by the year 2010.
• In 1957, at a dump site in Russia's Ural Mountains, several hundred miles from Moscow, buried nuclear wastes mysteriously exploded, killing dozens of people.
• Nuclear reactors only last for about forty to fifty years.

nuclear energy

Every US president is obliged to review its nuclear policy at least once during his occupation of office. The current incumbent, President Obama, presented his 2,200 page policy changes titled Nuclear Posture Review (NPR) on April 6, 2010. 
The salient features of his review comprise: top priority to fighting terrorism and proliferation vis-à-vis responding to a nuclear attack; promising not to use atomic weapons against non-nuclear states but issuing a stern warning for countries that ignore global non-proliferation rules; reducing the role of nuclear weapons in the US security strategy; expanding conventional capabilities, relying on existing stockpiles of nuclear weapons for deterrence against nuclear powers like Russia and China; and focusing on preventing terrorists and rogue states from acquiring such weapons.
Prima facie these are sound suggestions but the review must be examined in light of other contemporary developments. On April 8, the US president and his Russian counterpart, Medvedev, signed the Strategic Arms Reduction Treaty (START) at Prague. Under the Treaty, each side within seven years would be barred from deploying more than 1,550 strategic warheads or 700 launchers, without the compulsion of eliminating the “surplus” weapons. Result-antly, even with the planned reductions there will be enough firepower on each side to devastate the world many times over.
Amidst the backslapping and self-praise, the subject of Iran’s nuclear programme remained prominent. Medvedev obliquely spelt out Russia’s support for UN sanctions on Iran by stating that Tehran’s “intransigence” cannot be ignored. A third development is the two-day Nuclear Security Summit (NSS) with 47 heads of state and government in Washington on April 12 and 13. The focus of the unprecedented meeting was on: how to safeguard nuclear materials from terrorists. Pakistan was led by the head of its Nuclear Command Authority, PM Yousuf Raza Gilani. 
Coming back to the NPR, which promises not to use atomic weapons against non-nuclear states but issues a stern warning for countries that ignore global non-proliferation rules, Defence Secretary Gates has noted that there is no such commitment regarding Iran and North Korea. Tehran has reacted sharply to the US targeting the duo and threatening the use of nuclear weapons against them. Leading the charge, President Ahm-adinejad has accused Obama of being more war-mongering than Bush. In a televised speech, the Iranian president derided Obama, depicting him as an ine-ffective leader influenced by Israel to target Iran more aggressively.

The uranium enrichment process

The uranium enrichment process .

Using uranium as a fuel in the types of nuclear reactors common in the United States requires that the uranium be enriched so that the percentage of the uranium-235 isotope is increased, typically to 3 to 5%. Uranium enrichment is an isotopic separation process that increases the proportion of the uranium-235 isotope in relation to uranium-238 in natural uranium.
The enrichment process used in the United States involves combining uranium with fluorine to make uranium hexafluoride (UF6) followed by gaseous diffusion (see below). The UF6 output from gaseous diffusion is in two streams - one is increased, or enriched, in its percentage of U-235, and the other is reduced, or depleted, in its percentage of U-235. The depleted uranium hexafluoride product is referred to as "depleted UF6." After gaseous diffusion, the enriched uranium hexafluoride is subjected to further processing, while the depleted UF6 is generally stored.