Since 1952, there have been 33 recorded nuclear incidents worldwide. Out of these 33, three stand out as being some of the most effective to date...
Chernobyl is a city situated in northern Ukraine, currently abandoned due to the disaster at the Chernobyl Nuclear Power Plant located approximately nine miles away. 30 years later, Chernobyl is withing the 30 kilometer exclusion zone surrounding the former power plant. Before April 26th, 1986, over 16000 people lived in Chernobyl. Today, it is only inhabited by Zone administrative personnel, and former citizens who refused to leave their homes following the disaster.
Chernobyl before the meltdown
On April 26th, 1986, the plant was testing a way to cool the core of the nuclear reactor in case of an emergency. A rise of steam pressure within Reactor number 4 causes an explosion, lifting a 1000-ton lid used to contain radioactive fuel elements. This action immediately releases radiation into the air.
The oxygen in the air begins to go into the reactor, resulting in a graphite fire and a second explosion. The flaming debris lands on the lid of Reactor number 3. After this, 30 separate fires take place within the plant. Four hours later, reactor Number 3 is shut down; while Reactors 1 and 2 are shut down around 24 hours later.
During the Chernobyl disaster
What was the result?
Two workers within the facility were killed instantly, and 197 citizens were hospitalized with radiation sickness. To date, almost 5000 cases of thyroid cancer have been identified in children up to 18 years of age. 28 workers died as a result of ARS (acute radiation sickness) within the same year as the disaster (What, 2017).
THREE MILE ISLAND
Though this was the most serious accident in U.S. commercial nuclear power plant operating history, the incident had no detectable health effects on plant workers or the public. This reactor in Middletown, Pennsylvania melted down on March 28th, 1979 due to equipment malfunctions, design problems, and worker errors.
Three Mile Island before the accident
At 4 A.M. on March 28th, 1979, the plant experienced failure in one of the two reactors on the plant. A mechanical-or electrical- issue prevented the main feed-water pumps from bringing water to the steam generator, which removes heat from the reactors core. Because of this, both the turbine-generator and the reactor shut down, resulting in the rise of pressure in the nuclear section of the plant. The valve on the top of the pressurizer became stuck open and the cooling water was pouring out.
Matters were made worse when the workers decided to reduce the amounts of cooling water being poured into the primary system. The water began to overheat, causing the nuclear fuel to so the same.
Significant amounts of radiation were released from the plant's auxiliary building. Chemical reactions in the melting fuel caused the creation of a large hydrogen bubble within the dome of the pressure vessel (where the reactor core is held). If the bubble were to explode, the core would fall into the containment building. Fortunately, this did not happen, and the bubble eventually dissipated.
What was the result?
Thankfully, there were no fatalities within the Three Mile Island Catastrophe. However, this incident made the United States Nuclear regulatory Commission much more aware of protocol, to make sure something like this never happens again.
Here's just a few things they've done to ensure that:
- Upgrading/strengthening of plant design and equipment requirements.INCLUDING :fire protection, piping systems, auxiliary feed-water systems, containment building isolation, reliability of individual components,and the ability of plants to shut down automatically
- Creating new and more effective operator training and staffing requirements, improved instrumentation and controls for operating the plant, and establishment of programs for plant workers to protect against alcohol/drug abuse
- Emergency drills and response plans tested by licensees several times a year, state and local agencies participate in drills along with the Federal Emergency Management Agency and NRC.
CURRENTLY... the TMI-2 reactor is shut down and all fuel has been removed. FirstEnergy contracted to Exelon the right to monitor TMI-2. Both companies plan to keep the facilities in monitored storage until the TMI-1 reactor's licsense expires. Then, both plants will be recalled (Backgrounder, 2014).
Three Mile Island post-accident
Six years ago, a devestating earthquake damaged the Fukushima Daiichi Nuclear Plant in Japan. To this day, the area is still a hotspot for radioactivity and is not stable.
Fukushima before the meltdown
At approximately 2 P.M (EST), the fifth largest earthquake hit northern Japan, sparking a major tsunami. A wall of water 30 feet high hits Japan, resulting in the damage of anything within its path: including the Tokyo Electric Power Company's Fukushima Daiichi Nuclear Plant. The flood water reacts with the plants generators, resulting in their failure as the reactors heat up.
The Japanese government issues an emergency message for the plant,and the cooling systems begin to fail. Then, it is discovered the radiation levels within reactor Number 1 are rising, and the possibility of a radiation leak is rising. Within a matter of hours, the radiation levels are eight times more than its usual level.
Then, at 6:22 P.M., a hydrogen explosion at reactor Number 3 occurs, resulting in the injuries of four people. Those who live within 20 kilometers of the plant are told to evacuate. Authorities begin to distribute iodine tablets to prevent radiation poisoning. Three days later, a second explosion takes place at reactor Number 3 and 2, injuring 11 people. The next day, one more explosion takes place at reactor Number 2, followed by a fire at reactor Number 4. At this point, radiation levels at the plant are 167 times the average level. Though the levels have decreased greatly, Fukushima is still unstable (Jones, 2011).
Fukushima as the explosions took place
What was the result?
Since 2011, 173 children/young adults in Fukushima have been suspected or confirmed for thyroid cancer. According to the World Health Organization, the risk of thyroid cancer in females exposed as infants is as high as 70% (Global, 2013). Over 21,000 residents within the Fukushima exclusion zone were forced to abandon their homes as a result of the nuclear alert. Many have not returned home, as the area is still unstable (Japanese, 2016).