The Nuclear Present, Future, Past
Ever since 1945, we have been living in a nuclear age. Presently, much controversy revolves around nuclear physics. Some people want to see the nuclear industry grow. Others think that nuclear reactors and weapons should be no part of humankind. Some people also want to keep things the way it is right now. If you want to know more about the present, then read on.
Many countries have recently acquired nuclear weapons or are close to
These countries include North Korea, Israel, South Africa, India, Iraq, Iran, Syria, Libya, Algeria, and Pakistan. There is an overwhelming fear of mass destruction because of the large degree of nuclear proliferation. The current treaties and organizations which attempt to ensure the safety of the world from nuclear weapons include the Nuclear Nonproliferation Treaty and the International Atomic Energy Agency.
There will be much more debate about the consequences of nuclear proliferation. Some will argue that all nuclear weapons should be disposed of, where others will argue that the current international treaties and organizations will suffice to maintain the safety of the world from nuclear weapons.
There is also a fairly substantial fear that nuclear weapons might fall into the hands of terrorists. With so many recent acts of terrorism, many people fear the worst if these weapons of mass destruction are acquired by terrorists.
There are currently around two hundred nuclear power plants in the world which supply about one sixth of the world's energy. Because of disasters such as Chernobyl and Three Mile Island, more stringent safety laws and more effective safety mechanisms have been implemented. Because there haven't been any new power plants constructed recently and nuclear reactors only have a forty to fifty year lifetime, plans are being considered to replace dying power plants.
Currently, all nuclear energy is harnessed by the principle of nuclear fission. There is research being done to harness energy by means of nuclear fusion. As evidenced by the hydrogen bomb as opposed to the atomic bomb, nuclear fusion has the potential to generate much more energy.
The construction of the multi-billion dollar waste management investment Yucca Mountain is still continuing, with completion expected in the year 2010. Prompted by disasters such as the waste explosion at Russia's Ural Mountains, one of the main goal of this site will be safety.
There exists much controversy about future site selection for waste
sites. Nobody wants a
nuclear waste site in their backyard, but they have to be built somewhere. And, of course, there can never be an absolute guarantee of safety. There is always some risk.
In the present, there is still no way quantitatively tell how much radiation
a person has been exposed to. The best way right now is just an examination
of symptoms. However, many symptoms don't show up until days or weeks after
the exposure, so many doctors and hospitals waste their time on patients
with exposure to fatal amounts. Computer aided
tomography (CAT) and Nuclear Magnetic Resonance (NMR) imaging can help doctors
locate where the radiation occurs in the body and what type of radiation it is.
The current methods to treat patients with radioactive-dose-inflicted
cancers) are by replacement and chemotherapy. Although fairly effective, it is often hard
to find possible donors and additionally, the body might reject the transplant. However, the success rate is low enough to definitely warrant further research.
Currently understood relevant nuclear physical principles include:
•The Equivalence of Mass and Energy •Four Fundamental Forces of Nature
•gravitational force •strong nuclear force •weak nuclear force •and electromagnetic force
•Atomic and Subatomic Structure •Nuclear Fission •Nuclear Fusion •Types of Radiation
There are theories in developmental stages which hope to create a unified picture of the
fundamental forces of nature:
•Theory of Everything: The theories of everything are general terms given to theories which make an attempt at unification. •Grand Unification Theory: This is the most orthodox theory of unifying the fundamental forces of nature. The current task at hand is to unify the strong, weak, and electromagnetic forces. •Superstring Theory: An attempt is made to create a unified picture of all four fundamental forces of nature by modelling particles as strings and combining this string theory with a mathematical structure known as supersymmetry. Interestingly enough, this theory proposes the idea that the universe may not consist of only four dimensions as Einstein saw it, but instead of ten dimensions.
The Nuclear Future, Present, Past
The near future of nuclear science holds the potential for an explosion in technology and
controversy. Currently, there are many ongoing efforts to enhance human understanding
of nuclear science and to utilize nuclear energy more beneficially. Of course, how far
nuclear science actually advances is entirely unpredictable.
Although the Nuclear Nonproliferation Treaty is still intact, many countries have the potential of causing mass destruction to the rest of the world. The atomic bombs used against Japan in World War II were relatively small bombs as compared to the modern atomic and hydrogen bombs in existence today. To put this in perspective, a modern hydrogen bomb has the power of ten megatons,whereas all the explosives detonated in World War II, including the two atomic bombs, only combined to yield two megatons.
Technology will focus on increasing the accuracy of bomb and missile
delivery methods as
well as creating more effective defense mechanisms.
There will be much more debate about the consequences of nuclear proliferation. Some will argue that all nuclear weapons should be disposed of, whereas others will argue that the current international treaties and organizations will suffice to maintain the safety of the world from nuclear weapons.
The average lifetime for a power plant is between forty and fifty years. The first power plant opened in 1956, so we will probably see many power plants shutting down. With the gradual decline of common energy fuels such as coal and oil, in the future, people will have to make some tough decisions in terms of energy resources. Although many new types of energy such as water, solar, natural gas, geothermal, and wind are being extensively researched and tested, we can bet on nuclear energy as one of the future's main sources of energy. As many countries are seeking nuclear weapons, many countries will also be seeking nuclear power plants to power their lands.
Additionally, much more research will be conducted to maximize the safety
disasters such as Chernobyl and Three Mile Island. Future technology focuses on designing power plants which inherently cannot melt down.
There will also be much more research conducted with the hopes of making
(as opposed to nuclear fission) a way of harnessing energy. Current power plants all harness energy through nuclear fission.
The multi-billion dollar waste management investment Yucca Mountain
is scheduled to be
completed by the year 2010. This waste storage center will provide a safer and completely
regulated way to store waste.
In addition, alternative methods of waste disposal will also be investigated including disposal in space and in the ocean floors.
There will also be much controversy about future site selection for waste sites. Although urban areas consume most of nuclear-generated electricity, radioactive wastes are generally dumped in rural settings, where property values decline and public health is jeopardized. However, the problem of radioactive waste disposal is not unique to the United States. Other countries will be facing the same waste dilemmas.
As of yet, there is still no way to quantify the amount of radiation
a person has been exposed to. The best way right now is just an examination
of symptoms. However, many
symptoms don't show up until days or weeks after the exposure, so many doctors and
hospitals waste their time on patients exposed to fatal amounts. One method that is still in
development is the improvement of computer aided tomography and nuclear magnetic resonance imaging techniques.
Also, further methods are being investigated to treat patients who develop diseases (particularly cancers) as a result of radioactive doses. Currently, the only way to treat these cancers is by replacement. For example, the current treatment for leukemia is with bone marrow transplants to replenish the body's supply of white blood cells. Although this treatment somewhat effective, it is often hard to find possible donors. Additionally, the body might reject the transplant. In the future, scientists hope to formulate ways to "fix" the damaged blood cells.
There are theories that are in developmental stages which hope to create
a unified picture
of fundamental forces of nature: gravitational force, strong nuclear force, weak nuclear force, and electromagnetic force such as:
•Theory of Everything: The theories of everything are general terms given to theories which make an attempt at unification. •Grand Unification Theory: This is the most orthodox theory of unifying fundamental forces of nature. The current task at hand is to unify the strong, weak, and electromagnetic forces. •Superstring Theory: An attempt is made to create a unified picture of all four fundamental forces of nature by modeling particles as strings and combining this string theory with a mathematical structure known as supersymmetry. Interestingly enough, this theory proposes the idea that the universe may not consist of only four dimensions as Einstein saw it, but instead of ten dimensions.
The Nuclear Past, Future,Present
Oh what a glorious past the nuclear age has had. All this was started by a few ambitious scientists studying the nucleus and it has turned into mass destruction, efficient energy, and major controversy. As you delve into the history of the nuclear era, try to put in perspective the impact of a few early experiments on the world afterwards. No pun intended, but the nuclear age "exploded."
For history concerning the physics, consult the nuclear physics page.
•The Nuclear PAST
Major beginnings in developing nuclear explosions
It all started rather innocently in 1896, when Antoine Henri Becquerel discovered radioactivity in uranium. Becquerel, of course, did not envision the atom bomb when he made his discovery. The next step came in 1902 when Marie and Pierre Curie isolated a radioactive metal called radium. Three years later came an electrifying breakthrough, when Albert Einstein published his theory of relativity. Einstein asserted that matter (mass) and energy were two forms of the same thing. According to Einstein, if somehow we could transform mass into energy, it would be possible to "liberate" huge amounts of energy.
It was one thing to say this is theory, but it was another thing to do it. During the second decade of the century, a major step was taken in that direction when Ernest Rutherford and Niels Bohr described the structure of an atom more precisely. It was made up, they said, of a positively charged core, the nucleus, and of negatively charged electrons that revolved around the nucleus. It was the nucleus, scientists concluded, that had to be broken, disintegrated, "exploded," if atomic energy was to be liberated.
Fermi discovers nuclear fission
In 1934, Enrico Fermi of Italy disintegrated heavy atoms by spraying them with neutrons. Unfortunately, he didn't realize that he had achieved nuclear fission. In December 1938, however, Otto Hahn and Fritz Strassman in Berlin did a similar experiment with uranium and were able to verify a world-shaking achievement. They had split an atom. They had produced nuclear fission. They had transformed mass into energy--33 years after Einstein had said it could be done.
Einstein writes a letter to the president
And on August 2, 1939, Albert Einstein wrote a letter to the American
D. Roosevelt. "In the course of the last four months,: he said, "it has been made probable--through the work of Joliot in France as well as Fermi and Szilard in
America--that it may become possible to set up nuclear chain reactions in a large mass of
uranium... This new phenomenon would also lead to the construction of bombs... A single
bomb of this type, carried by boat or exploded in a port, might very well destroy the whole
port together with some of the surrounding territory." He urged Roosevelt to begin a
nuclear program without delay. In later years Einstein deplored the role he had played in
the development of such a destructive weapon: "I made one great mistake in my life," he
told Linus Pauling, another prominent scientist, "when I signed the letter to President Roosevelt recommending that atoms bombs be made."
The Manhattan Project
Roosevelt gave the note to an aide with the notation: "This requires action." For the next six years scientists, engineers, generals, government officials joined hands in the Manhattan Project-a massive enterprise to produce an atomic bomb. Sometimes the pace was slow, especially at the beginning, when even Fermi had doubts that the job could be done. In its later stages the pace was feverish.
The government spent more than $2 billion constructing a number of special research laboratories, hiring scientists and engineers, and building thirty-seven installations in nineteen states and Canada. Oddly enough, despite the scope of the effort, the secret was so well kept that practically no one outside a small select circle knew what was going on.
Dropping the bomb/The Second World War
So the development of the bomb continued. And on August 6, 1945, the
Enola Gay, an
American airplane, dropped the first atomic bomb ever used in warfare on Hiroshima,
Japan, eventually killing over 140,000 people. On August 9, 1945, the United States drops
a second atomic bomb, this time on the Japanese city of Nagasaki. The drop is one mile
off target, but it kills 75,000 people.
The Hydrogen Bomb
The hydrogen bomb works by the principle of fusion. After much debate
including opposition from Enrico Fermi and the General Advisory Committee of the
Atomic Energy Committee, on January 31, 1950, President Truman made the decision to
developed these massive weapons. "I believe," he writes in his memoirs, "that anything
that would assure us the lead in the field of atomic energy development for defense had to
be tried out..."
The man usually referred to as the "father" of the hydrogen bomb is Edward Teller, a immigrant from Hungary. Teller began thinking of a fusion bomb early in the 1940's. Scientists had known for decades that mass could be converted into vast amounts of energy through fusion by taking atoms of a light element such as hydrogen and fusing them.
A problem he faced was that fusion could only occur at multimillion-degree
There was nothing on earth that hot--except the atom bomb. The atom bomb, in fact, is
the trigger for the hydrogen bomb. It provides the heat that fuses tritium and deuterium,
and in the process releases innumerable fast neutrons both to explode the fuel and to fission the bomb's uranium jacket. The H-bomb, in fact, is not a fusion bomb per se, but a fission-fusion-fission bomb.
On November 1, 1952, on a Pacific islet called Elugelab, in the Eniwetok
technicians detonated a 50-ton cubical box about two stories high, code-named Mike.
Humankind had entered the second phase of the nuclear era, the hydrogen-bomb phase.
As described by nuclear scientist Ralph Lapp, a massive fireball consumed the little island
"sucking up millions of tons of coral, and water turned to steam." A hundred thousand feet
above ground the ball was three miles in diameter. Down below, nothing remained of the
islet of Elugelab except a hole 175 feet deep and a mile in diameter. The adjacent island was "wiped clean"; had any human beings remained there, they would have instantly perished. "Mike," the device that devastated Elugelab, had the power of 12 megatons; it was almost a thousand times more powerful than the A-bomb that had consumed
Hiroshima seven years earlier.
In the 19th century, the rapid advance of modern technology and industrial
greatly increased both the destructive power of armed forces and the capacity of societies
both to resist and to recover from an attack. Nuclear weapons, carry the possibilities of
destruction to a new level, and they are able to inflict far greater damage within a few hours than previously resulted from years of warfare. This not only makes the consequences of war worse but also raises new concerns about controlling such a destructive process. Indeed, nuclear weapons have not been used in war since the first two atomic bombs were dropped on Japan in 1945, but many countries, including many Third World countries, now have nuclear weapons.
The Cold War
After the second world war the USA and the Soviet Union emerged as the two dominating states of the world. German, Italy and Japan were defeated; France and Great Britain were severely weakened. Although the Soviet Union had suffered great losses during the second world war it had a strong position in 1945: Soviet troops controlled the major parts of East Europe.
USA was the single Great Power that had almost not been directly affected
by the war. It had also built a big industry and was the only country in
the world to have nuclear weapons at the end of world war II. Only a couple
of years later, the USSR had them too. The USA and the USSR had both become
super powers. The Iron Curtain was a fact and in 1948 the American writer
Walter Lippmann introduced the concept "Cold War".
X-rays were discovered in 1895 and X-ray technology was developed in order to produce photographic images of the insides of the human body. Unfortunately, this technique proved not to be very effective when radiation is involved because it's difficult to distinguish between healthy and damaged tissue. Also, it provided a two dimensional image which was deficient because of its inability to discriminate among overlapping structures. The basic principle behind x-ray imaging is that x-rays are really thin so they can penetrate the body and produce a photographic representation on film placed behind the x-rayed region. And of course, x-rays always have the potential of doing harm to a person.
Computer Aided Tomography
Computer aided tomography (CAT) was first developed in 1966. This was somewhat like an x-ray system in that x-rays were used. However, this provided a three dimensional image. X-rays were shot at different angles in order to preserve viewpoints. Images were collected by a detector array, displayed on a TV monitor and photographed for later use after the image has been reconstructed by a computer which calculates a representative three dimensional image based on the various cross-sectional x-ray images. However, since x-rays were used, there was still a potential risk involved.
Nuclear Magnetic Resonance Imaging
Nuclear magnetic resonance (NMR) imaging was first developed in theory in the year 1952 by Felix Bloch of Stanford University and Edward M. Purcell of Harvard University who later shared a Nobel prize. NMR imaging gives a more precise three dimensional image and has the ability to distinguish even more characteristics of tissue. NMR imaging does not involve the use of x-rays but rather produces images due to the spins of atomic nuclei.
Fermi produces nuclear fission from a reactor
The first in history test--of the world's first man-made nuclear reactor,
Enrico Fermi's famous "pile," CP-1 took place on December 2, 1942, in a
squash court under the stands of the University of Chicago's Stagg Field.
Fermi, the Italian Nobel laureate physicist, led the team that day. The
pile, as it waited in the dark cold of Chicago winter, was a black,
greasy, flattened-ovoid hulk--a doorknob as big as a garage--stacked with 771,000 pounds of 16-inch graphite bricks, 80,590 pounds of uranium oxide pucks, and 12,400 pounds of uranium-metal slugs, the uranium components dropped into blind holes bored into the graphite bricks in a roughly spherical lattice. CP-1 cost about $1 million to build. It had no shielding. It had no cooling. Fermi intended to run it no hotter than half a watt, but no one doubted that its mechanism, if it worked, could someday be applied to the production of power. Such power would keep submarines in perpetual motion underwater, a few people in the U.S. Navy had quickly realized. Others, including Fermi's young physicist colleague Walter Zinn, were already thinking about power for civilian electricity.
When enough neutrons fissioned the U-235 nuclei, Fermi reasoned, a chain reaction should occur, each fission causing two more fissions, two causing four, four causing eight, eight causing sixteen, in a geometric progression that could ultimately generate enough heat and radiation to burn up the pile if Fermi didn't limit the reactor with control rods. In CP-1 the handmade wooden rods were wrapped with sheets of cadmium, a metal that hungrily absorbs neutrons. By moving one or more control rods in or out of holes in the pile, allowing the cadmium to absorb greater or lesser numbers of neutrons, Fermi could accelerate, slow, or stop the chain reaction. If something happened to the control rods, he had a suicide squad in reserve: three young scientists with jugs of cadmium-sulfate solution waited near the ceiling of the squash court, ready to flood the pile with cadmium and quench any runaway reaction at the risk of their lives.
Through the morning and early afternoon the historic experiment proceeded. Mid afternoon, an eyewitness remembers, "suddenly Fermi raised his hand. 'The pile has gone critical,' he announced. No one present had any doubt about it." The reaction had become self-sustaining. The pile's neutron intensity at that point was doubling every two minutes as the chain reaction proceeded. Left uncontrolled for an hour and a half, that rate of increase would have carried CP-1 to a million kilowatts.
Fermi ran the pile for four and a half minutes at one-half watt before he shut it down. It was 3:53pm. "The Italian navigator has landed in the new world," an administrator whispered into the telephone to Washington. A force of nature had been released by an inspired application of human ingenuity; for good and for ill, forever after, it would have to be reckoned with. Nothing very spectacular had happened. Nothing had moved and the pile itself had given no sound. Yet, for some time they had known that they were about to unlock a giant; still, they could not escape an eerie feeling when they knew they had actually done it.
The government steps in
Through many acts and organizations including the Atomic Energy Act
of 1946 and the Congressional Joint Committee on Atomic Energy, the government
made atomic energy in all its manifestations an absolutely monopoly and
sought out to monitor and control nuclear development, building test reactors
and even test weapons. Between 1964 and 1970, U.S.
utility companies placed orders for some 100 reactors. The bandwagon rolled.
Three Mile Island
One minute past 4 a.m. on Wednesday, March 18, 1979, maintenance workers cleaning sludge from a small pipe blocked the flow of water in the main feed water system of a reactor at Three Mile Island near Harrisburg, Pennsylvania. The sift foreman heard "loud, thunderous noises, like a couple of freight trains," coming from Unit 2. Loudspeakers broadcast warnings. Since the reactor was still producing heat, it heated the blocked cooling water around its core hot enough to create a pressure surge which popped a relief valve. Three emergency feed water pumps started up to restore circulation.
But the relief valve stuck open, and some 220 gallons of water per minute began flowing out of the reactor vessel. Two valves that normally channeled water from the emergency pumps on the system could have supplied the reactor vessel with enough cooling water to replace the escaping water, but he control-room operators didn't know that the valve was stuck open.
Within five minutes after the main feedwater system failed, the reactor, deprived of all normal and emergency sources of cooling water, and no longer able to use its enormous energy to generate electricity, gradually started to tear itself apart.
The loss of coolant at the reactor continued for some 16 hours. About a third of the core melted down. Radioactive water flowed through the stuck relief valve into an auxiliary building, where it pooled on the floor. Radioactive gas was released into the atmosphere. An estimated 140,000 people were evacuated from the area. It took a month to stabilize the malfunctioning unit and safely shut it down. The reactor was a total loss and the cleanup required years and cost hundreds of millions of dollars.
No one was reported injured and the little radiation that leaked out was quickly dispersed. Although this accident did cost lots of money and time, no one was hurt. Three Mile Island inspired the NRC mandated safety modifications to nuclear plants throughout the United States that averaged $20 million per plant. "It is not an exaggeration to say," Cohen concludes, "that lessons learned from the Three Mile Island accident revolutionized the nuclear power industry."
A far more serious accident occurred at Chernobyl, in what was then
still the Soviet Union.
At the time of the accident April 26, 1986--the Chernobyl nuclear power station consisted of four operating 1,000 megawatt power reactors sited along the banks of the Pripyat River, about sixty miles north of Kiev in the Ukraine. A fifth reactor was under construction.
All the Chernobyl reactors were of a design that the Russians call the RBMK--natural uranium-fueled, water-cooled, and graphite-moderated--a design that American physicist and Nobel laureate Hans Bethe has called "fundamentally faulty, having a built-in nstability."Because of the instability, an RMBK reactor that loses its coolant can under certain circumstances increase in reactivity and run progressively faster and hotter rather than shut itself down. Nor were the Chernobyl reactors protected by containment structures like those required for U.S. reactors, though they were shielded with heavy concrete covers.
Without question, the accident at Chernobyl was the result of a fatal combination of ignorance and complacency. "As members of a select scientific panel convened immediately after the... accident," writes Nobel laureate Hans Bethe, "my colleagues and I established that the Chernobyl disaster tells us about the deficiencies of the Soviet political and administrative system rather than about problems with nuclear power."
Although the problem at Chernobyl was relatively complex, it can basically be summarized as a mismanaged electrical engineering experiment which resulted in the reactor exploding. The explosion was chemical, driven by gases and steam generated by the core runaway, not by nuclear reactions. Flames, sparks, and chunks of burning material were flying into the air above the unit. These were red-hot pieces of nuclear fuel and graphite. About 50 tons of nuclear fuel evaporated and were released by the explosion into the atmosphere. In addition, about 70 tons were ejected sideways from the periphery of the core. Some 50 tons of nuclear fuel and 800 tons of reactor graphite remained in the reactor vault, where they formed a pit reminiscent of a volcanic crater as the graphite still in the reactor had burned up completely in a few days after the explosion.
The resulting radioactive release was equivalent to ten Hiroshima's. In fact, since the Hiroshima bomb was air-burst--no part of the fireball touched the ground--the Chernobyl release polluted the countryside much more than ten Hiroshima's would have. Many people died from the explosion and even more from the effects of the radiation later. Still today, people are dying from the radiation caused by the Chernobyl accident. The estimated total number of deaths will be 16,000.
"We are glad that you find the information useful." Regards, Johann Schleier-Smith
Present, Future, Past
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