Nuclear Technology

Nuclear Energy

Nuclear energy is America’s second largest source of electric power, next to coal. The efficiency of more than 110 nuclear power plants across the U.S. has saved American consumers about $44 billion since 1973. Nuclear energy cuts down on oil dependence. It reduces environmental impact because vast amounts of fossil fuels need not be burned. Nuclear energy plants produce electricity by the fission of uranium, not the burning of fuels. As a result, nuclear power plants don’t pollute the air with such toxins as sulphur oxides, nitrogen oxides, dust or greenhouse gases such as carbon dioxide.

More than 400 nuclear plants are operating in 25 countries around the world. They supply almost 17% of the world’s electricity. With its proven benefits over three decades, nuclear energy will continue to play a major role in producing the electric power that the world will need to fuel its economic growth in the decades to come.

Between 1973 and 1991, nuclear energy displaced 7.7 billion barrels of oil world wide. In 1991 alone, nuclear energy displaced 670 million barrels of oil, 4 trillion cubic feet of gas and 650 million tons of coal world wide.

Nuclear Reactors - A nuclear reactor produces heat by splitting uranium atoms. The heat boils water into high-pressure steam that drives an electric generator. Canadian reactors, known as CANDU reactors, use fuel made of natural uranium, which contains only a small amount of the special uranium needed to produce a fission reaction in the reactor.

Nuclear Weapons

Nuclear weapons are the most powerful man made destructive force. We now possess the ability to destroy the planet that keeps us alive. If an all-out nuclear war were to occur, the human race would probably not survive. Nuclear weapons were the main concern of many nations after World War II. The two main nuclear powers would have to be the United States and Russia, (Canada never has not constructed a nuclear weapon). In a nuclear war there are no winners; everybody suffers, especially the planet Earth itself.

Early nuclear weapons were dropped as bombs, but now they have the mobility of missiles. The USA could attack Russia without even sending a plane. Their nuclear missiles can leave their launch site, and travel above the Earth’s atmosphere all the way around the planet until they approach their target. They can then re-enter the atmosphere and strike. As a result of this planetary range, there is virtually no safe place on Earth to be during a nuclear war.

Even if there were survivors of a nuclear strike, they wouldn’t live very long. As a result of nuclear war, there is a phenomenon known as Nuclear Winter. It results from the rising dust clouds and fallout materials. The clouds block out the sun’s rays and heat, causing a global temperature drop. This causes unseasonably low temperatures world wide. Almost all living things would die if a Nuclear Winter were to occur.

Today, there are measures being taken to ensure that a catastrophic event such as Nuclear Winter will never happen. Nuclear super-powers are disarming their nuclear weapons, and treaties have been signed; but how much good do treaties and disarmament do? No one is safe as long as there are nuclear weapons in existence.

Nuclear Disasters

Intense heat, fireball radiation traveling at the speed of light, shock waves at the speed of sound; all of these result in mass destruction and tens of thousands of deaths. Nuclear disasters are a scary thought that we all have to live with. Most people recognize the names Chernobyl, Hiroshima, and Nagasaki as representatives of such lethal disasters.

During World War II, the allies struggled to create an ultimate weapon, and succeeded. On July 16, 1945 in the Southern New Mexico desert, the first nuclear bomb was dropped. For the first time, their destructive potential was realized. The allies then proceeded to drop a nuclear bomb on Hiroshima, a city in Japan. The city was basically destroyed, many people were killed, and many died later due to the effects of radiation. Japan, however, did not surrender after this first attack; the Allies struck again, this time in Nagasaki. Japan quickly surrendered after this second defeat.

The fallout of this attack can still be felt today. The survivors of this attack will never forget the day they almost died. About 600,000 people were living in Hiroshima and Nagasaki at the time of the bombings. 180,000 immediate deaths were caused by the bombs, mainly from the blast and heat, compounded by radiation. About 100,000 survivors have been monitored medically over the past 40 years. Many people died as a result of nuclear fallout; radiation caused genetic mutations in the unborn, and cancer in the unfortunate people who were relatively close to ground zero.

The effect of Nuclear bombs has been realized since the disasters at Hiroshima and Nagasaki. Presently the United states and Russia are involved in disarming their Nuclear Arsenal.

 

Chernobyl

Chernobyl is a horrific reminder of how dangerous nuclear technology can be. Even in as far away a place as Russia, a nuclear disaster is still felt world wide. The meltdown of Chernobyl happened on April 25 1986, and was mainly caused by human error. Chernobyl released 5000 tons of materials into the atmosphere. Forty tons containing boron and absorbing neutrons, 2400 tons of lead, and 1800 tons of sand and clay. This huge amount of fallout made its way around the globe. The destruction of Chernobyl caused many people to think about or change their opinions concerning nuclear energy.

The Biological Effects of Radiation Exposure

The millisievert is a unit of measurement corresponding to radiation exposure levels.

0.01-0.1 millisievert

Typical annual exposure to the most exposed members of the public as a result from Ontario Hydro’s nuclear generating stations. No detectable health risk.

2-3 millisieverts

Normal background radiation from natural sources each year at sea level; the average minimum dose received by most people on earth. The probability of this exposure causing cancer is 1 in about 10,000.

100 millisieverts

If given instantaneously, would not cause obvious illness; could cause cancer in the following years in 5 of every 1000 people exposed. (Normal cancer deaths are 200-250 per 1,000 people).

1,000 millisieverts

If given instantaneously, may cause nausea, but probably not death; would cause cancer in following years in about 50 of every 1,000 people exposed.

4,500 millisieverts

If given instantaneously, would cause nausea in first hours, followed by blood cell damage. Some deaths would occur in the first weeks after the exposure. Medical treatment could reduce the subsequent death rate. However, about 50 percent of the exposed individuals are likely to die.

10,000 millisieverts

If given instantaneously, would cause immediate illness and death within a few weeks, even if medical treatment is provided.

Nuclear Waste

With all of the benefits that nuclear technology has to offer us, we are faced with the problem of its toxic and hazardous by-products. Radioactive waste comes in many different forms, including used fuel rods, old tools from nuclear power plants, old medical radiation equipment from hospitals and clinics, and even used smoke detectors. Radioactive waste produced by nuclear reactors as a result of nuclear fission is the biggest problem facing the nuclear power industry today. Finding safe ways of storing radioactive wastes so they do not leak radiation into the environment is a difficult task. According to a 1983 report by the U.S. National Academy of Sciences, it will take 3 million years for radioactive waste stored in the U.S. as of that year to decay to background levels. Radioactive waste is classified into three main categories: High-level waste, mill tailings and low-level waste.

High-level waste: This category consists mostly of spent nuclear fuel from commercial power plants and military facilities. It can emit large amounts of radiation for hundreds of thousands of years. Commercial plants in the U.S. produce 3,000 tons of high-level waste each year. A spent fuel rod contains 94% irradiated uranium. Nuclear power plants generally store their spent fuel rods on-site in lead lines concrete pools of water. These pools keep the rods relatively cool and somewhat contain the spread of gamma radiation. On-site storage is intended as a temporary measure, and space is running out at many plants. Long-term storage of high-level waste requires a waterproof, geologically stable repository and leak-proof waste containers.

Mill-tailings: These materials are left over when ore is refined and processed. Only 1% of uranium ore contains uranium - the remainder is left on-site as sand-like residue. These tailings are generally left outdoors in huge piles, where they blow around, releasing radioactive thorium, radium, and radon into the surrounding air and water. Although their radiation is generally less concentrated than that in other forms of waste, some of the isotopes in these tailings can continue to emit radiation for many thousands of years. Before they were discovered to be hazardous, mill-tailings were used in certain building materials. Upon discovery of this problem, measures were taken to ensure adequate cleanup of the dangerous materials.

Low-level waste: Low level waste includes all radioactive waste that does not fall into the high-level waste or mill-tailings category. Examples are contaminated reactor water, and materials created in medical laboratories, hospitals, and industries. Wastes in this category usually (but not always) release smaller amounts of radiation for a shorter amount of time. These wastes, although low-level, are still dangerous. This type of waste is usually disposed of in special low-level waste landfill sites. These sites provide a false sense of "out of sight, out of mind" security. An alternative to these landfills is to store the waste at existing nuclear plant sites.


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