Monday, April 4, 2011

Nuclear Chemistry Applied to the Real World




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Basics on nuclear reactors:
·         Nuclear reactors contain and controls nuclear reactions (1)
·         They are mainly used for generating electricity (1)
·         Produce medical isotopes for imagining and cancer treatments (1)
·         There are many different types of nuclear reactors- pressurized water reactor, boiling water reactor, sodium cooled fast reactor, high temperature gas rector.. ect (1)

Parts of a nuclear reactor:
·         The core- contains all of the nuclear fuel and generates all of the heat (1).
·         The coolant- material the passes through the core. The coolant transfers the heat from the fuel to a turbine (1).
·         The turbine- transfers heat from the coolant to electricity (1).
·         The containment- separates the reactor from the environment, usually shaped like a dome and constructed of high-density steel enforced concrete (1).
·         The cooling towers- where they dump the excess heat that cannot be converted into energy (1).
The Nuclear Core:
·         Fuel Pins (1):
o   smallest unit in the reactor (1)
o   typically uranium oxide (1)
o   surrounded by cladding to keep fission particles from escaping (1)

·         Fuel assembly (1):
o   collections of fuel pins (1)
o   fuel is put in and taken out through the fuel assemble (1)


·         Full Core (1):
o   made up of fuel assemblies (1)
o   can vary (1)
Chernobyl:        
·        Occurred April 26, 1986 (2)
·        Chernobyl was a nuclear power plant located in the marshlands of Ukraine (2).
·        Its first reactor began working in 1977 and the fourth and final reactor began working in 1983 (2).
·        After the fourth plant began working a small town, Pripyat, was created outside the plant to house families that worked at Chernobyl (2).
·        On April 25  1986 reactor four was shut down for routine maintenance, during the maintenance they were also going to check the reactor to insure that the turbines could produce enough energy and cold water in case of a power outage (2 and 3).
·        The tests began at 1 am on April 25.  During the tests Alexander Akimov shut down several of the safety systems, the test was then delayed nine hours due to a power demand in Kiev (3).
·         On 1 am on April 26, the reactors power dropped creating a horrible situation, the reactor exploded 23 minutes later (2).
·         Two days after the explosion monitors of other power plants around Europe began noticing high levels of radiation from their plants (2).
·         However the Soviets tried to cover up this nuclear disaster and denied it (2).
·         Pripyat was evacuated two days after the explosion went off but the town of Chernobyl wasn’t evacuated until six days later (2).

Remedy of Chernobyl:
·         Tried to pour water on the fires and stop them with sand, however when that proved to not work, they began to try to stop the fires with lead and nitrogen (2).
·         Two weeks later all the fires were put out but during that time people were told to stay indoors (2).
·         Soil and water were placed in barrels in order for the radiation and contamination to not spread (2).
·         They enclosed the remains of the fourth reactor in a concrete box so no additional radiation would leak out (2).

What went wrong at Chernobyl?
·        Chernobyl did not have containment (1).
·        During the tests several of the reactors safety systems were shut off (2).
·        The engineers who designed the tests for Chernobyl were specialists in electric generators, as opposed to nuclear reactors, and little discussion with nuclear reactor specialists was made prior to the test (3).
·        During the test the grid needed power for a longer time than was expected (3).
·        Because the test was to take place after midnight there was a new shift on duty and the new shift was not briefed on the procedure (3).
Lasting effects of Chernobyl:
·         31 people died shortly after the explosion but thousands more died due to the effects of the radiation (2).
·        The reactor created a cloud of radioactive materials (5)
·        Cesium-137 is still found in soil and food in Europe because of its long half life(5)
·         Pripyat is now a ghost town (6)
·         A quarter of a million people moved away from their homes (6)
·         The search for alternative energy is larger than the search for nuclear energy (6)
Chernobyl vs. Japan Today
·        similarities:
o   houses were evacuated (7)
o   radiation lingers in the air (7)
o   used lead to help put out the fires (7)
·        differences:
o   the reaction in Japan went worldwide almost immediately where as a Chernobyl the Soviets tried to hide the fact
o   Fukushima was caused because of a natural disaster while Chernobyl was caused because of a carless mistake
·         Should we be worried?
o   No Americans should not be worried; they do not expect harmful levels of radiation to reach the west coast (7).
o   They are constantly monitoring the radiation levels in American just in case (7).
Works Cited: