Chernobyl Essay, Research Paper
: The Chernobyl disaster on April 26, 1986 is described as one of
the most frightening environmental disasters in the world. The
plant was made up of four graphite reactors, which were the most
modern Soviet reactors of the RBMK-type. Two more of these reactors
were still under construction at the station. Chernobyl was an
obscure town in north central Ukraine (former Soviet Union) on the
Pripyiat River near the Belarus border. Immediately its name was
joined to the Nuclear Power Plant located twenty-five kilometers
upstream. The plant is actually located fifteen kilometers
northwest of the city. It is not only the radioactive mess left
that strikes fear. Nineteen similar stations are still running,
because neither the former Soviet Union nor its republics can
afford to shut them down. The world first learned of this accident
from Sweden, where unusually high radiation levels were noticed at
one of their own nuclear facilities.
At 1:23 am technicians at the Chernobyl Plant took some erroneous
actions that will impact the course of Soviet events without
exaggeration. Human error is what basically caused the disaster.
These operators of the fourth unit slowly allowed power in the
reactor to fall to low levels as part of a controlled experiment
gone wrong. The purpose of the test was to observe the dynamics of
the RMBK reactor with limited power flow. Twelve hours after power
reduction was initiated, power reached 50 percent. Only one turbine
was needed to take in the decreased amount of steam, so no. 2 was
turned off. Power was then reduced to 30 percent. One of the
operators made a mistake. Instead of keeping power at 30 percent,
he forgot to reset a controller, which caused the power to plummet
to 1 percent. Now water was filling the core, and xenon (a neutron
absorbing gas) built up in the reactor. The power was too low for
the test. The water added to the reactor is heated by the nuclear
reaction and turned into steam to turn the turbines of the
generator. The operator forced the reactor up to 7% power by
removing all but 6 of the control rods. This was a violation of
procedure and the reactor was never built to operate at such low
power. This type of reactor is very unstable when filled with
water. The operator was not successful in getting the flow of water
corrected and the reactor was getting increasingly unstable. The
operator disabled emergency shutdown procedures because a shutdown
would abort the test. By 01:22 AM, when the operators thought they
had stable conditions, they decided to start the test. The operator
blocked automatic shutdown because of a fear that a shutdown would
abort the test and they would have to repeat it. The test began and
the remaining turbine was shut down. Power in the reactor began to
gradually rise because of the reduction in water flow caused by the
turbine shutdown, which lead to an increase in boiling. The
operator initiated manual shut down, which lead to a quick power
increase due to the control rod design. The reactor reached 120
times its full power. All the radioactive fuel disintegrated, and
pressure from all excess steam broke every one of the pressure
tubes and blew the entire top shield of the
reactor. All of these factors including serious violations of
safety operations, dangerous design flaws, and imperfect control
systems is what led to the virtually instantaneous
catastrophic increase of thermal power which led to core meltdown.
The steam explosion also destroyed part of the building.
Radioactive material was then thrown out into the atmosphere for
over 10 days. Multiple fires were formed both inside and out of the
reactor. By five o’clock the firemen had smothered the flames.
In later days, about 5000 tons of materials were thrown into the
reactor well from helicopters of the air force to extinguish
burning graphite and suppress radiation release. The flow of
different substances continued until the beginning of June 1986. It
is still not clear if the dumping of these materials actually
achieved their goal. Recent data has shown only a small part of the
materials actually got into the well.
Due to the accident, the people of Chernobyl were exposed to
radioactivity 100 times greater than the Hiroshima bomb. The people
of the world and Northern Europe were greeted with clouds of
radioactive material being blown northward through the sky.
Seventy
percent of the radiation is estimated to have fallen on Belarus and
10 years later babies are sill being born with no arms, no eyes, or
only stumps for limbs. No one can predict the exact number of human
victims. It is estimated that over 15 million people have been
victimized by the disaster in some way. It has also estimated that
ultimately the accident will claim more victims than World War II.
It will cost over 60 Billion dollars to make these people healthy.
Thirty-one lives were lost immediately, and more than 600,000
people were involved with the cleanup. Many are now dead or
sick.
Hundreds of thousands had to abandon entire cities and settlements
within the thirty-kilometer zone of highest contamination. Possibly
as many as three million still live in contaminated areas. Ten
thousand of these are still living in the city of Chernobyl today.
Huge sums of many have been spent, and will continue to be spent to
relocate settlements and decontaminate the once rich farmlands.
Chernobyl has developed as an icon for the terror of uncontrolled
nuclear power and abilities, and for Soviet deception and inability
to provide safe conditions for workers and basic services such as
transportation and health care, especially in times of greatest
need. The catastrophe also halted a highly potential nuclear
program.
The impact of the Chernobyl Accident on a Nuclear Energy Policy is
tremendous. Some countries stopped national nuclear energy
programs. Construction of new plants in the Soviet republics were
frozen. Public opinion was directed against nuclear power plants.
Some plants were even shut down, but have now been reactivated. The
accident has also initiated an international activity in the area
of nuclear safety and nuclear emergency planning. Many countries
started a development of decision support systems for nuclear
accident cases.
The way in which Soviet leaders have dealt with the situation is
very unsettling. In the aftermath of the catastrophe several
designs to encase the damaged reactor were reviewed. The option
that was selected included the construction of a massive structure
in concrete and steel that used what remained of the reactor walls
as support. Its construction is considered one of the most
complicated building works in the world. In charge of building the
tomb was Construction Department No. 605. They ran into many
problems while constructing the massive concrete and steel shell.
Concrete blocks for the tomb were pieced together far from the
reactor itself, and the roads entering the facilities were not
accommodated for such loads, which made it difficult for the
drivers. Once the blocks were delivered, the workers needed to put
them in place. Each weighed several dozen tons so eventually crane
operators had to perform this task.
This outer protective wall, 28 stories high, is placed around the
perimeter and other walls connected to the Unit 3 reactor. A steel
roof then completed the structure. The destroyed reactor was
entombed in a 300,000-ton concrete structure known as the “shelter”
or “envelope.” In conditions of high radioactivity the mammoth task
was completed in seven months, in November 1986. The site around
the plant had then been announced safe for about the next thirty
years. However today the sarcophagus is cracked and crumbling. Some
of these cracks are as large as a garage door.
Multiple sensors were placed to monitor levels of gamma radiation,
neutron flux, temperature, heat flux, as well as the concentrations
of hydrogen, carbon monoxide and water vapor in the air. Other
sensors monl
On the whole, there are some different points and aspects from the
authors to explain the effects of immigration on labor market. They
are the demand and supply, investment, expenditure form government,
skilled immigrants, mobility and the empirical findings. Although
there are both advantages and disadvantages from immigration, most
authors believed that there is no causal link between immigration
and unemployment. However, it is possible that they emphasized the
benefits and gave insufficient attention to the costs of
immigration on the labor market. In my view, government should
consider more aspects from the effect of immigration on labor
market for making the policy well. Also, government should not put
most responsibilities of unemployment on immigration in order to
escape the blame from high unemployment because it is not fair to
the contribution from immigration and make an unreal image of
immigration to society.
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