Nuclear Disasters

Jonathan Dorsey and Carter Johnstone

Big image

What is a Nuclear Power Plant Disaster?

A nuclear power plant disaster generally occurs when the core in a nuclear reactor is damaged from overheating. The resulting effects can be devastating to both the environment and surrounding life/people, spreading dangerous radiation that can harm organic life. Nuclear power plants produce energy through nuclear fission, or the separation of the nucleus of an atom. Almost all power plants use the more fission-prone isotope of uranium-uranium-235-located in the core of the reactor. Basically, a neutron is shot at high speeds at a sample of uranium-235 which then splits into Barium-142 and Krypton-91, along with 3 neutrons and gamma rays (gamma radiation), beta particles, and an enormous amount of kinetic energy (the particles collide at high speeds). The resulting neutrons then go on to collide with other uranium samples, and the process continues.

Reaction in Nuclear Power Plants

Big image

Fukushima Nuclear Meltdown

Fukushima Japan Nuke Reactor #3 Explosion (Full view)
The Fukushima nuclear power plants are among the largest in Japan. They consist of two separate plants, one located at Daiichi, one at Daini. On the Friday of March 2011, an earthquake of magnitude 9.0 caused the formation of a tsunami in the Pacific Ocean. The tsunami struck the Daiichi power plant and disabled both the cooling system and power supply. Normally, when power is lost, the backup diesel generators would turn on and continue to power the plant until it was safely shut down. However, the 15-foot tidal wave flooded the generators, rendering them useless. The coolant systems without power were too rendered useless, and the water in the coolant system continued to be heated by the ongoing nuclear reaction (despite the lack of power, the residual uranium-235 samples continued to react and produce energy). Volatile fission products too continued to be released as the coolant system was offline. One of these products was hydrogen, which ignited in reactors 1, 2, 3, and 4 and caused a large hydrogen explosion (as seen in the video above). An evacuation of the surrounding 20 kilometers of land was ordered in order to protect citizens from radioactive materials. While there were no deaths from radiation poisoning following the meltdown, almost 100,000 people were forced to evacuate and during the ensuing natural disaster that was the tsunami, almost 1,000 died out of the 100,000 that evacuated. Later, a small amount of radioactive material was released into the Pacific Ocean, and INITIALLY after monitoring, the effect of this material on marine life was practically negligible. Likewise, as of 2013, the containment zone has been reduced by 2/3. However, samples of radioactive material in water were still being discovered by the beginning of 2012 in amounts deemed dangerous for infants. To this day, fishing is still prohibited in that region of Japan as the levels of nuclear waste in the ocean is considered astronomically higher than what was first thought.
Big image

Three Mile Island Accident

In March 1979, a series of mechanical and human errors at the Three Mile Island nuclear generating plant near Harrisburg, Pennsylvania, resulted in an accident that profoundly affected the utility industry. The power plant, a pioneer nuclear plant, paved the path for generating energy in the future. The accident occurred when the reactor was operating at 97%. There was a malfunction with the cooling circuit which caused the uranium core to overheat. The nuclear plant automatically went into shutdown , however, the operators were unable to correctly analyze and respond to the unplanned occurrence. The operators hurriedly tried to fix the coolants in order to cool the still hot core. While they did cool down the uranium core, radioactive gases from the reactor were released into the environment. In the following months of the accident, suspicions raised and worries growing, meticulous investigations were conducted to research the true effects of the accident. With thousands of samples tested, the effects of the increased nuclear radiation proved to have negligible on effects physical health and the environment. Even with little physical affects, the people of America became ambivalent towards generating energy via nuclear substances. New reforms and requirements were enforced in order to create a safer way to have nuclear energy. Plant designs, equipment requirements, emergency preparedness requirements, and scheduled inspections were all effects of The Three Mile Island Accident.

Big image

Chernobyl - The Biggest Man-Made Disaster

The town of Chernobyl is in Ukraine near the borders of Russia and Belarus and was a nuclear power site created by the Soviets. The Soviets planned to have a total of six reactors made and 4 were already constructed at the time of the disaster. Reactor #4 had been operating for two years with regular safety and procedural checks. However the monitoring procedures were inadequate and reactor #4 had a meltdown which spewed 400 times the amount of radiation released at Hiroshima and Nagasaki. The fires created by the explosion required 800,000 Soviet firefighters. 25,000 of these people died and 70,000 of these people became disabled. The evacuation procedures that affected the surrounding areas were like no other. 300,000 people left their homes never to come back. The disaster at Chernobyl was also spread worldwide. Nuclear rain quickly spread ephemerally throughout nearby areas. A total of 93,000 cancer related deaths were linked to the disaster. Although pensions were given to the surrounding countries, nothing would be able to reverse the psychological affects caused by disaster. However, the region has become one of the world's most unique wildlife sanctuaries with thriving populations of wolves, deer, beavers, eagles, and other animals. Officials say that it could take up to 100 years before the station is completely decommissioned with 200 tons of radioactive materials still left inside the reactor.
Chernobyl fires send radiation particles in atmosphere

Our Opinion

Despite the environmental fallout and resulting nuclear waste releases, we believe that these nuclear power plant disasters were beneficial in the long run. While the environment may have been harmed, human learning and experience with nuclear power plants has greatly increased in response to the nuclear power plant failures. For example, after the Three Mile Island incident in Pennsylvania, the United States took measures to ensure that a similar nuclear meltdown wouldn't occur again. Reforms were implemented that tightened restrictions on the production of nuclear energy and plant designs were entirely reconstructed in order to prevent the escape of volatile radioactive gases in the event of a meltdown. Likewise, the disaster at the Fukushima Daiichi plant taught us that despite having a state-of-the-art facility, a nuclear meltdown can still occur. Even though there were numerous safety measures in place to prevent a meltdown such as the backup generators and vent stacks and the coolant system, four of the six reactors still experienced a meltdown and released their radioactive toxins into the air. Also, the Fukushima disaster highlighted the ineffectiveness of the communication system in many nuclear plants; records of the evacuated were not kept, vital information regarding health advisories and evacuation necessity were deleted, the disaster itself was mismanaged (radioactive gases continued to be released into the air weeks after the meltdown), and inaccurate surveys regarding the amount of radioactive waste released were conducted. Now, communication among workers has been reformed, and new improvements in nuclear reactors such as Passive Auto-catalytic hydrogen Recombiners (machines that combine dangerous hydrogen gas with oxygen to form water), 3-day backup batteries for battery-powered generators, and Filtered Containment Venting Systems (systems that successfully cool and vent the reactor core without the use of electricity) are being introduced that will ensure shutdown in the event of an emergency. In summation, nuclear power plant disasters have all shed light on the flaws within the industry and have helped create a more reliable form of nuclear energy production through reforms and innovations.